Section 2.

Engine
Refer to Fig.2-1 and Fig.2-2 for front and side sectional views of the engine.

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Fig.2-1. Side sectional view of the engine

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Fig.2-2. Front sectional view of the engine

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 Fault diagnosis
Symptom/fault Remedy

Engine fails to start

1. Carry out the following operations:
1. No fuel to carburettor:
- blow fuel pipes, clean fuel tank, renew fuel filter;
- blocked fuel pipes or fuel filter;
- clean filters;
- clogged carburettor or fuel pump filters;
- check pump operation and renew any damaged components
- faulty fuel pump
2. Refer to section «Ignition system»
2. Ignition system fault
3. Carry out the following:
3. Carburettor fuel cutoff solenoid fails to open at ignition switch-on:
- check wiring and connections, renew damaged wires;
- disconnected, loose or broken wiring to solenoid or solenoid control
unit;
- faulty solenoid control unit; - renew control unit;
- defective fuel cutoff solenoid - replace solenoid with a new one
4. Carburettor choke not opening at first flashes in cylinders 4. Eliminate any leakage of choke pull-down unit

Engine idles erratically or stalls

1. Incorrectly adjusted idle speed 1. Adjust idle speed

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2. Defective carburettor solenoid control system 2. Refer to «Engine fails to start»
3. Faulty carburettor: 3. Carry out the following:
- blocked carburettor jets or internal passages; - blow carburettor jets and internal passages;
- water in carburettor; - remove water from carburettor, drain sludge from fuel tank;
- broken choke control diaphragm - fit new diagram
4. Ignition system fault 4. Refer to section «Ignition system»
5. Vacuum leak through damaged hose between intake pipe and brake 5. Replace damaged hose
servo unit 6. Tighten retaining nuts or renew gaskets; eliminate carburettor flange
6. Air leak through gaskets at connections between intake pipe and car- deformation or fit new carburettor
burettor/cylinder head 7. Fit new pipe in place of damaged one
7. Leaking distributor vacuum pipe

Engine lacks power and has poor acceleration

1. Partly open throttle 1. Adjust throttle linkage
2. Choked air cleaner element 2. Change filter element
3. Ignition system fault 3. Refer to section «Ignition system»
4. Faulty fuel pump 4. Check pump operation and renew any damaged components
5. Faulty carburettor: 5. Carry out the following:
- faulty accelerator pump; - check pump operation, renew damaged parts;
- blocked main jets; - blow jets with compressed air;
- partly open choke; - adjust choke operation;
- low fuel level in float chamber; - adjust float;
- leaky throttle enrichment diaphragm - replace diaphragm
6. Restricted fuel tank vent pipe 6. Blow pipe with compressed air
7. Incorrect valve clearances 7. Adjust valve clearances
8. Misaligned timing marks 8. Adjust timing belt accordingly, align timing marks
9. Insufficient cylinder compression - below 1 åP‡ (10 kgf/Òm ): 2
9. Carry out the following:
- broken or sticking piston rings; - clean piston rings or grooves from carbon deposits, renew damaged com-
- poor valve-to-seat fitting; ponents;
- replace damaged valves, regrind valve seats;
- excessively worn cylinders or piston rings - replace pistons, rebore and hone cylinders.

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 Main bearing knocking
Typical knocking or thumping noticeable at sudden throttle opening at idle which intensifies with higher crankshaft rate. Excessive endfloat
of crankshaft causes sharper irregular knocking, especially noticeable during smooth increase or decrease in crankshaft speed.
1. Early ignition 1. Adjust ignition timing
2. Insufficient pressure oil 2. Refer to subsection «Insufficient oil pressure at idle»
3. Loose flywheel securing bolts 3. Tighten bolts to torque specified
4. Excessive main bearing running clearance 4. Grind journals and renew bearing shells
5. Excessive thrust washers-to-crankshaft clearance 5. Fit new thrust washers, check clearance

Big-end bearing knocking

Big-end bearing knocking is sharper than that of main bearings. It is noticeable during engine idle at sudden throttle opening. The origin of
knocking can be easily identified through switching off spark plugs one at a time.
1. Insufficient oil pressure 1. Refer to «Insufficient oil pressure at idle»
2. Excessive big-end bearing running clearance 2. Fit new bearing shells and regrind journals

Piston slap
Thumping noise caused by piston «runout» in cylinder. Most noticeable at low crankshaft speed and under load.
1. Excessive piston-to-cylinder bore clearance 1. Renew pistons, rebore and hone cylinders
2. Fit new rings or new pistons with rings

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2. Excessive gudgeon pin-to-piston groove clearance

Knocking of intake or exhaust valves

Excessive valve clearances cause typical regular noise; its frequency is lower than the frequency of any other engine noise, since the valves
are operated by camshaft rotating at half the crankshaft speed.
1. Excessive valve clearances 1. Adjust clearances
2. Broken valve spring 2. Renew spring
3. Excessive valve-to-guide clearance 3. Replace worn parts
4. Worn camshaft lobes 4. Renew camshaft and levers
5. Loose locknut of adjuster bolt 5. Adjust clearance between lever and cam, tighten locknut

Excessive noise of camshaft operation line

Noise from camshaft operation line is caused by clearances between engagement elements and becomes noticeable in general engine noise
at low crankshaft speed.
1. Tighten chain
1. Loose chain caused by general wear
2. Renew tensioner shoe or damper
2. Broken chain tensioner shoe or damper
3. Eliminate seizure
3. Seized chain tensioner plunger rod

Insufficient oil pressure at warm engine idle

1. Foreign particles entrapped under oil pump relief valve 1. Clean valve from foreign particles and flash, clean oil pump
2. Seized oil pressure relief valve 2. Renew valve
3. Worn oil pump gears 3. Repair oil pump
4. Excessive main bearing running clearance 4. Turn journals and renew bearing shells
5. Excessive camshaft bearing journal-to-bearing housing clearance 5. Renew camshaft or bearing housing
6. Incorrect oil grade or inappropriate oil quality 6. Change oil as recommended in Attachment 4

Excessive oil pressure on warm engine

1. Seized oil pressure relief valve 1. Renew valve
2. Excessively tough spring of oil pressure relief valve 2. Renew spring

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 Excessive oil consumption
1. Oil leaking through engine gaskets 1. Tighten fittings or replace gaskets and oil seals
2. Restricted crankcase ventilation system 2. Wash components of crankcase ventilation system
3. Worn piston rings 3. Rebore and renew pistons and rings
4. Broken piston rings 4. Renew rings
5. Foul windows of oil scraper rings or foul slots in piston grooves due to 5. Clean windows and slots of carbon, change motor oil as recommended in
wrong oil Attachment 4
6. Worn or damaged valve oil caps 6. Renew oil caps
7. Badly worn valve stems or guides 7. Renew valves, repair cylinder head

Excessive fuel consumption

1. Choke not fully opened 1. Adjust choke linkage
2. Excessive resistance to vehicle motion 2. Check and adjust pressures in tyres, braking system, wheel alignment
3. Incorrect ignition timing 3. Adjust ignition timing
4. Defective distributor vacuum unit 4. Renew vacuum unit or ignition distributor
5. High fuel level in carburettor: 5. Carry out the following:
- leaking needle valve or its gasket; - check for any foreign matter entrapped between needle and valve seat;
renew valve or gasket as applicable;
- seizure or excessive friction hindering normal float operation - check and when necessary replace floats

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6. Choked carburettor air jets 6. Clean jets
7. Leaking part throttle enrichment diaphragm 7. Replace diaphragm
8. Carburettor solenoid failed to shut off fuel at overrun: 8. Following to be done:
- no earthing of idle switch sliding contact; - clean solenoid contact surfaces;
- broken wire between control module and carburettor idle switch; - check wiring and connections, renew damaged wire;
- faulty control module - renew control unit

Engine overheating
Coolant temperature gauge needle is in the red sector. Start tracing the failure with checking coolant temperature gauge and its sender (Refer
to section «Instrumentation»).
1. Slackened pump and alternator drive belt 1. Adjust drive belt tension
2. Insufficient coolant in system 2. Top up coolant to cooling system
3. Incorrect ignition timing 3. Adjust ignition timing
4. Dirty radiator outside 4. Clean radiator outside with water jet
5. Defective thermostat 5. Renew thermostat
6. Faulty radiator cap inlet valve (opening pressure is below 0.07 MPa 6. Renew cap
(0.7 kgf/cm2)
7. Defective coolant pump 7. Check pump operation, renew or repair pump

Sudden coolant drop in expansion tank

1. Damaged radiator 1. Repair or renew radiator
2. Damaged cooling hoses or pipe gaskets, loose clips 2. Renew damaged hoses or gaskets, tighten hose clips
3. Leaking heater tap or heater matrix 3. Renew tap or heater matrix
4. Leaking water pump seal 4. Renew seal
5. Damaged radiator cap or cap seal 5. Renew cap
6. Defective cylinder head gasket 6. Renew gasket
7. Leaks from fissures in cylinder block or cylinder head 7. Check cylinder block and cylinder head for leakage; renew damaged com-
ponents in case of evident cracking
8. Leaks from fissures in water pump housing, water jacket return pipe, 8. Check for leaks; renew components in case of fissures; minor leaks can
thermostat, expansion tank or intake pipe be cured by adding a radiator sealant such as çààëë-1

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 Engine - removal and refitting Undo the nuts holding the downpipe to exhaust manifold.
Detach the downpipe from the bracket on the transmission and
Put the vehicle on a lift or over an inspection pit and apply the lower it down.
handbrake. Take out the spare wheel and its supporting pipe.
Slacken the clips, disconnect the hoses from the fuel pump and
Disconnect the battery leads and withdraw the battery. Unbolt secure the pump in the position that excludes any fuel leakage.
and remove the bonnet. Detach the fuel return hose from the carburettor.
To remove the air cleaner, disconnect its hoses, remove the Release the clips and disconnect the hoses from the heater
cover and filter element. Temporarily plug the carburettor. manifolds, detach the brake servo hose from the intake pipe.
Disconnect the throttle linkage and choke cable. Use socket spanner 02.7812.9500 to unbolt the starter motor
Disconnect the wires from the fuel cutoff solenoid, idle switch, from the clutch housing. Undo the bolts holding the clutch hous-
oil pressure sensor, coolant temperature sensor, ignition distribu- ing cover to the lower clutch. Using Ä.55035 undo the clutch bell-
tor, alternator and starter motor. housing to the cylinder block.
Drain coolant from the radiator, cylinder head and heater unit. Hoist the beam íëé-3/379 and secure the engine right side
To do this, shift the heater tap control lever to the right, undo the to the lifting yoke at the front exhaust manifold stud, while the left
caps on the cylinder block left side and radiator right-hand fluid side shall be secured through the clutch housing mounting hole.
cooler, screw instead the return hoses connectors, then undo the Slightly tension the hoist, undo the nuts that retain front
caps of the expansion tank and radiator. engine mounting rubbers 3 (Fig.2-3) to the side brackets, undo
Separate the fan cowl halves and remove the fan blower the nut and bolt holding the front axle housing to the engine

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cowl. Disconnect the coolant supply and return hoses from the brackets. Disconnect the engine negative lead.
engine. Undo two bolts retaining the radiator to the body, release Lift out the engine, first raise its top in order to take the bolts
the top catch of the fan cowl, move the top radiator toward the of the mounting rubber out of the bracket holes, then move the
engine and withdraw the radiator from the engine bay complete engine forward in order to release the input shaft from the bear-
with the thermostat and associated hoses. Remove the fan cowl. ing in the crankshaft flange.

Fig. 2-3. Engine mounting unit:

1 - right-hand support bracket with rubber; 2 - left-hand support bracket; 3 - mounting rubber; 4 - cross-piece, rear mounting; 5 - bracket with rear mounting

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Fig.2-4. Removing the oil filter using tool Ä.60312 Fig.2-5. Releasing the crankshaft nut using tool Ä.50121

Remove the starter motor heat shield, followed by the starter

motor, hot air intake complete with the supply hose. Remove from
the cylinder head two side brackets together with the front engine
mounting rubbers.

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Unbolt the clutch and withdraw it.
Refitting is a reversal of the removal procedure. Draw special
attention to the engine-to-transmission connection: the input shaft
must precisely engage the clutch disc splines. Furthermore, for
perfect engine/transfer box centering, the centering washers of
the front engine mounting rubbers must be in the respective side
brackets holes.

Engine - dismantling
Flush the engine, mount it on a stand for dismantling and
drain the oil sump.
Remove the carburettor, for that disconnect the hoses and
throttle operating rod.
Remove the fuel pump and ignition distributor. Use spanner
67.7812.9514 to unscrew the spark plugs and coolant tempera- Fig.2-6. Removing the chain tensioner and damper:
ture sensor. 1 - camshaft timing chain; 2 - shoe retaining bolt; 3 - tensioner chain; 4 - ten-
sioner retainer nut; 5 - tensioner housing; 6 - tensioner cap nut; 7 - chain
Remove the alternator and water pump drivebelt. Remove the
damper securing bolts; 8 - oil pump shaft sprocket retaining bolt
alternator and its retaining bracket.
On the pump and exhaust manifold disconnect the coolant camshaft and oil pump drive shaft sprockets.
supply pipe from the heater. Slacken chain tensioner cap nut 6 (Fig.2-6), undo nut 4 hold-
From the pump and exhaust manifold disconnect the coolant ing it to the cylinder head, remove the tensioner; then unbolt and
supply pipe from the heater. remove chain tensioner shoe 3.
Use tool Ä.60312 to undo the oil filter with seal, remove the Undo the chain stop pin, remove the oil pump and camshaft
oil filter and seal (Fig.2-4). sprockets, then take off the chain.
Unscrew the oil pressure warning lamp sender. Remove the Loosen studs 4 nuts (Fig. 2-7). Remove the camshaft bearing
crankcase vent breather cover, crankcase and oil pump. Remove housing. Undo studs 4 nuts, remove thrust flange 1 and withdraw
the oil separator drain pipe catch and take out the oil separator. the camshaft exercising maximum care not to damage the
To remove the crankshaft pulley, secure the flywheel using camshaft bearing housing surface.
Ä.60330/R (Fig. 2-10) and undo the nut using tool Ä.5012 (Fig. 2- Unbolt the cylinder head and withdraw it complete with the
5). Withdraw the valve cover and timing cover. Unbolt the exhaust manifold and intake pipe.

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Fig.2-7. Removing the camshaft thrust flange:
1 - thrust flange; 2 - camshaft; 3 - bearing housing; 4 - thrust flange securing Fig.2-8. Removing the oil pump shaft:
stud 1 - thrust flange; 2 - flange securing bolt; 3 - oil pump shaft; 4 - wrench

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Remove thrust flange 1 (Fig.2-8) of the oil pump drive shaft
and take the shaft out of the cylinder block.
Using picker Ä.40005/1/7 (kit Ä.40005) drive the sprocket off
the crankshaft (Fig.2-9).
Undo the connecting rod bolts, remove the big end cap and
carefully lift the pistons with the conrods through the cylinders.
Mark the piston, connecting rod, main and big-end bearing shells
for position to facilitate the reassembly.

WARNING. When removing the pistons and conrods, do

not press out the connecting rod bolts.

Fit tool 5 (Fig.2-10), undo bolts 3, remove washer 4 and the

flywheel from the crankshaft. Remove the front clutch housing Fig. 2-9. Removing the crankshaft sprocket using a picker
cover.
Using tool Ä.40006, take the input shaft bearing out from the
crankshaft (Fig.2-11).
Remove the crankshaft oil seal retainer.
Unbolt the main bearing cap bolts, remove them complete
with the lower bearing shells, then lift out the crankshaft, top
bearing shells and rear bearing thrust washers.

Engine - reassembly
Follow the engine reassembly procedure as below:
Locate a clean cylinder block and screw in any missing dow-
els. Oil the crankshaft bearing shells, thrust washers, pistons and
Fig.2-10. Removing the flywheel:
oil seals. Always fit new crankshaft oil seals when reassembling 1 - wrench; 2 - flywheel; 3 - flywheel securing bolt; 4 - washer; 5 - tool
the engine after overhaul. Ä.60330/R to lock the flywheel stationary; 6 - front clutch housing cover

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Fig.2-11. Pressing out the bearing from the crankshaft using tool A.40006 Fig. 2-12. Refitting the thrust washers to the rear mounting

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Fit the centre main bearing shells without an oilway into the
bearing recesses. Fit into other cylinder bores the bearing shells
with an oilway, while into the relevant main bearing caps - the
bearing shells without an oilway. Lower the crankshaft into posi-
tion, then stick two thrust washers into the rear bearing recesses
(Fig.2-12).

WARNING. The washers must be fitted so that their oil-

ways face away from the bearings in the block and cap (anti-
friction coat is applied on the washer surface). At the rear of
the rear main bearing there fitted a sintered thrust washer
(yellow), while at the front - a steel-aluminium thrust washer. Fig.2-13. Marks on the main bearing caps (bearing are numbered from the
engine front end)
Locate the main bearing caps according to the marks on their
outer surface (Fig.2-13). Tighten the cap securing bolts.
Check the crankshaft endfloat. To do this, turn the cylinder
block to have the rear side up and position the dial gauge foot
against the crankshaft flange (Refer to Fig.2-14). Moving the
crankshaft up and down (using screwdrivers, for instance), check
the crankshaft endfloat to be within 0.06-0.26 ÏÏ. If not, adjust
accordingly and replace the old thrust washers with new ones or
fit thicker thrust washers.
Locate the rear oil seal housing gasket on the crankshaft
flange, insert the front clutch housing cover bolts into the respec-
tive bores (Fig.2-15). Place the oil seal housing on tool
41.7853.4011 and slide it to on the crankshaft flange; next secure
it to the cylinder block with the bolts.
Locate front clutch housing cover 6 (Fig.2-10) over two cen-
tering pins (Fig. 2-16). Secure the cover to the rear oil seal hous-
ing with nuts. Fig.2-14. Checking the crankshaft endfloat

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Fig.2-15. Crankshaft rear oil seal housing. Fig.2-16. Clutch dowels (arrowed black) and clutch housing centering
The lugs (arrowed) for centering the housing against the crankshaft flange pins (arrowed white)

Locate the flywheel in position so that the marking (a cut-out)

near the rim is against the No 4 cylinder crankpin axis. While

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holding the flywheel stationary with tool Ä.60330/R, bolt it to the
crankshaft flange to the specified torque.
Using a ring compressor (tool 67.8125.9502), fit the pistons
and connecting rods to the cylinders (Fig.2-17).

WARNING. The hole for gudgeon pin in the piston is 1.2

mm set off, so the arrows on the piston crown must face the
timing belt end of the engine when inserting the pistons into
the cylinders.

Press the big-end bearing shells into the connecting rods and
caps. Guide the conrods and big-end caps onto the crankshaft Fig.2-17. Fitting the pistons complete with piston rings using ring com-
journal, then tighten the connecting rod bolts. The big-end caps pressor; centering pins of the cylinder head (arrowed)
must be positioned so that the cylinder number on the cap is
Tighten the cylinder head bolts in the established procedure
against the cylinder number on the connecting rod big-end.
(Fig.2-18) in four steps to ensure a reliable fit and exclude further
Refit the crankshaft sprocket. Locate the oil pump shaft and
tightening during vehicle servicing.
secure it with the thrust flange.
1st step - tighten the bolts 1-10 to 20 N•m(2 kgf•m);
Insert two centering pins into the cylinder block (Fig.2-17) and
2nd step - tighten the bolts 1-10 to 69.4-85.7 N•m
locate the cylinder head gasket over them.
(7.1-8.7 kgf•m), while the bolt 11 to 31.36 -
WARNING. Always fit the new cylinder head gasket. 39.1 N•m (3.2-3.99 kgf•m);
Never re-use the old gasket. 3rd step - turn the bolts 1-10 to 90°;
Before refitting the gasket, remove any oil from the mat- 4th step - turn again all bolts 1-10 to further 90°.
ing surfaces of the block and cylinder head. Make sure the
gasket is perfectly clean and dry. Avoid any incidental oiling WARNING. The cylinder head bolts can be re-used only
of the gasket. when their length is not in excess of 120 mm, otherwise
renew the bolt.
Turn the crankshaft so that the pistons are midway in the Before reassembly, immerse the bolts, thread and head,
cylinder bore. into engine oil. Allow the excess oil drip for at least 30 min-
Refit the cylinder head complete with the valves, exhaust utes. Remove all entrapped oil from the bolt bores in the
manifold and intake pipe over the centering pins. cylinder head.

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 Turn the flywheel so that the mark on the crankshaft sprock-
et is against the cylinder block mark (Fig.2-19).
Check to see the camshaft bearing housing centering pins
are in position (Fig.2-20). Refit the sprocket to the camshaft com-
plete with the bearing housing and turn the camshaft so that the
timing mark in the sprocket is aligned against the mark on the
bearing housing (Fig.2-21). Remove the sprocket and without
changing the camshaft position, refit the bearing housing to the
cylinder head so that the centering pins are in the respective
bores of the bearing housing. Secure the bearing housing, tight-
ening the nuts in the sequence as shown in Fig.2-22.
Refit the chain vibration damper.
Refit the camshaft timing chain:
- fit the chain onto the camshaft sprocket and position the
sprocket so its TDC mark is aligned with the respective mark on
Fig. 2-18. Cylinder head bolt tightening sequence the bearing housing (Fig.2-21). Do not tighten the sprocket bolt
fully;
- fit the sprocket to the oil pump shaft, but do not tighten the
retaining bolt fully;

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- fit the chain tensioner shoe and tensioner, but do not tight-
en the cap nut so that the tensioner spring can compress the
shoe; screw the chain stop pin into the cylinder block;
- turn the crankshaft two turns forward to ensure the chain
tension required; check the indentations in the sprockets are
aligned with TDC marks in the cylinder block and bearing hous-
ing (Fig.2-19 and Fig.2-21);
- when the marks are aligned, hold the flywheel stationary
with tool Ä.60330/R (Fig.2-10), then tighten the sprocket securing
bolts and chain tensioner cap nut to the torques specified, bend
the sprocket bolt lock washers; should the marks are not aligned,
repeat the chain refitting procedure.
Fig. 2-19. Aligning the timing marks on the crankshaft sprocket and cylin-
der block

Fig.2-21. Aligning the timing mark on the camshaft sprocket against bear-
ing housing mark:
Fig.2-20. Centering pins for camshaft bearing housing 1 - mark in sprocket; 2 - mark on bearing housing

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 Fig.2-23. Timing cover
Fig.2-22. Camshaft bearing housing nuts tightening sequence Projections (arrowed) for cover centering against crankshaft pulley hub

Adjust the clearance between the camshaft lobes and valve Fit the valve cover complete with the gasket and fuel piping

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levers. bracket.
Refit the camshaft cover (Fig.2-23) complete with the gasket Fit the air cleaner, to do this secure the hoses to the air clean-
and oil seal to the cylinder block, do not tighten the retaining bolts er housing, fit the filter housing complete with the gasket to the
and nuts fully. Using tool 41.7853.4010 centralize the cover carburettor, then fit the mounting plate and secure the housing
against the crankshaft end, then tighten the retaining nuts and with nuts. Locate the filter element and secure the air cleaner
bolts to the torques specified. cover.
Fit the alternator and oil pump pulley, then secure it with the Reconnect the HT leads to the distributor and spark plugs.
nut. Fill the engine with motor oil through the oil filler in the valve
Fit the oil filter complete with the gasket, manually screw it to cover.
the union on the cylinder block. Refit the crankcase vent oil sep-
arator, breather cover and secure the oil separator drain pipe with
the clip.
Fit oil pump 1(Fig.2-24), then fit the oil sump with the gasket.
Fit the coolant pump, alternator bracket and alternator. Fit the
belt around the pulleys and adjust the belt tension.
Fit the heater matrix supply pipe and cooling water jacket out-
let pipe to the cylinder block. Secure the heater matrix drain pipe
to the coolant pump and outlet pipe.
Fit the instrumentation sensors.
Fit the oil pump / distributor gear, followed by the ignition dis-
tributor. Insert the spark plugs, place spanner 67.7812.9515 on
the spark plugs and tighten the spark plugs with a torque wrench
to the torques specified.
Fit the fuel pump as outlined in section «Fuel system».
Fit the carburettor and reconnect the hoses. Cover the car-
burettor with a provisional cap.

WARNING. Never secure the carburettor (or tighten its Fig.2-24. Refitting the oil pump:
retaining nuts) when it is warm. 1 - oil pump; 2 - drain pipe lock; 3 - oil separator drain pipe

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Engine run-in after overhaul WARNING. Never check the engine or vehicle on the
roller stand without additional rollers for the front wheels.
After overhaul the engine is bench tested (run-in) at no loads
under the following cycle:
750-800 rpm 2 minutes Cylinder block
1000 rpm 3 minutes
1500 rpm 4 minutes
General description

2000 rpm 5 minutes The cylinder block basic sizes are shown in Fig.2-25.

Locate the engine on the test bench, start the engine and The cylinder block is of a low-alloyed cast iron. The cylinder
make checks with respect to the following items: bores are of five classes in steps of 0.01 mm and are designated
by the letters A, B, ë, D, Ö. The cylinder class is engraved on the
- evidence of coolant or fuel leaks through mating compo-
cylinder block bottom face. (Fig.2-26).
nents, pipe connections or gaskets;
The cylinders can be rebored to accommodate the oversize
- oil pressure and oil leaks through gaskets;
pistons of 0.4 mm and 0.8 mm bigger diameters.
- ignition timing;
The main bearing caps are machined complete with the cylin-
- idle speed; der block; therefore they are not interchangeable and feature dis-
- carburettor / intake pipe tightness; tinctive notches on the outside surface (Fig.2-13).
- abnormal knock.

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In case of any malfunctions or unknown rattle, stop the Inspection and repair
engine, eliminate the faults, then continue the tests.
Inspection. Wash the cylinder block thoroughly and clear the oil-
In case of oil leaks through the gasket between the valve
ways. Blow dry with compressed air and inspect the cylinder
cover and cylinder head or through the gaskets between the oil
block visually. Make sure there are no cracks in the mountings or
sump, cylinder block and covers, tighten the securing bolts to the
elsewhere in the cylinder block.
torque specified. If oil leaks persist, check the correct fitting of the
gaskets and renew when applicable. When cooling water is suspected in the crankcase, use a
special test bench to examine the cylinder block for leaks. To do
Since the overhauled engine is not fully bed-in and frictions
this, plug the cylinder block cooling water jacket ports, force in
between the working surfaces of renewed parts show significant
some room temperature water at 0.3 MPa (3 kgf/sq.cm). There
resistance to the rotation, a certain run-in period is required.
should be no evidence of water leaks from the cylinder block with-
This especially concerns those engines, where the pistons, in 2 minutes.
main / big-end bearing shells have been renewed, or the crank-
When coolant is found contaminated with oil, do not strip the
shaft journals have been reground, or the cylinders - honed.
engine completely, rather check the cylinder block for cracks in
Therefore during run-in after the engine overhaul, never allow the area of the oilways. For that, drain the coolant from the cool-
the engine to run at maximum loads. When in the vehicle, always ing system, remove the cylinder head, refill the cylinder block
run-in the engine at the speeds which are recommended for the water jacket with water and apply compressed air to the vertical
run-in periods. oilway in the cylinder. If there are any bubbles in the water of the
cooling water jacket, renew the cylinder block.
In-vehicle engine inspection after overhaul Examine the split face between the cylinder block and cylin-
Locate the engine in the vehicle, thoroughly check its correct der head using a straight-edge and feeler blades. Position the
mounting. straight-edge diagonally and using a feeler gauge measure at the
centre, both transversely and longitudinally. The flatness to be
Run the engine for a while, then check for:
within 0.1 mm tolerance.
- coolant or fuel leaks through pipe connections, tighten when
necessary; Cylinder repair. Check the cylinders for wear to be maximum
- full throttle opening and closing by the carburettor cable, 0.15 mm.
adjust accordingly, if necessary;
When available, use a dial inside gauge to measure the bore
- alternator drivebelt tension, adjust, when applicable; diameter (Fig.2-27) in four lands, both longitudinally and trans-
- reliable wiring connections and operation of the warning versely (Fig.2-28). Use tool 67.8125.9502 to set the inside gauge
lamps in the instrument cluster. to zero.

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 cardiagn.com
Fig.2-25. Basic sizes of the cylinder block

Fig.2-27. Measuring the cylinder bore with the inside dial gauge:
Fig.2-26. Cylinder size class engraved on the cylinder block 1 - inside dial gauge; 2 - setting to zero against reference gauge

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 There is practically no wear in the land 1 area of the cylin- There are five classes (Ä, Ç, ë, D, Ö) of the piston according
ders. Compare the values measured on the first and other cylin- to their major diameter, in steps of 0.01 mm. The piston has a
der lands to see the amount of the cylinder wear. complex outside shape: tapered in height and oval in the cross-
When the maximum wear is over 0.15 mm, rebore the cylin- section area. Therefore, the piston diameter must be measured
ders to the nearest oversize; provide 0.03 mm honing allowance in the plane normal to the gudgeon pin at 55 mm from the piston
on the diameter. Hone the cylinder walls so that the difference crown.
between the oversize piston diameter and cylinder bore is 0.025 There are three classes (1, 2, 3) of pistons, as to the hole for
- 0.045 mm. the gudgeon pin, in step of 0.004 mm. The classes of piston
diameters and holes for the gudgeon pin are stamped on the pis-
ton crown (Fig.2-30).
Pistons and connecting rods
The oversize piston major diameter is 0.4 or 0.8 mm bigger.
The 0.4 step is marked in the form of a triangle, while the 0.8 mm
General Description step is marked as a square.
The basic sizes of the pistons and connecting rods are Use the arrow on the piston crown for correct piston orienta-
shown in Fig.2-29. tion and fitting within the cylinder. The arrow of the piston must
Piston is an aluminium casting. The piston weight is face the timing belt end of the engine.
precisely maintained during the manufacturing process. Gudgeon pin is of steel, hollow, floating-type, i.e. freely
Consequently, there is no need to select the matching piston of operates in the piston bosses and connecting rod bush. The gud-
the same weight class during the engine assembly. geon pin is secured in the hole with two circlips.

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As to the outside diameter the gudgeon pin are of three
classes in step of 0.004 mm. The class is paint marked on the
gudgeon pin face: 1st class - blue paint, 2nd class - green paint,
3rd class - red paint.
Piston rings are of cast iron. The top compression ring has
a chromed barrel face. The bottom compression ring is of the
scraper type. The oil control piston ring features chromed work-
ing edges and has a coil expander (spreader ring).
The oversize rings are marked as 40 or 80, which corre-
sponds respectively to 0.4 or 0.8 mm step in the major diameter.
Connecting rod is of forged steel.The connecting rod is
machined together with the big end cap, therefore they are inter-
related. The cylinder number (6 in Fig.2-30) is stamped on the
caps and connecting rods to prevent confusion when refitting into
Fig.2-28. Measuring the cylinder bore:
A and B - direction of measurement; 1, 2, 3 and 4 - No of lands the cylinders. During reassembly the figures on the connecting
rod and cap should face the same side.

Fig.2-29. Basic dimensions of pistons and connecting rods

21
 The connecting rod small-end features a pressed-in steel- rod. The engine must always be fitted with the connecting rods of
bronze bush. As to the diameter of the bush, the connecting rods the same weight class. The connecting rod weight can be adjust-
are divided into three classes in steps of 0.004 mm (similar to the ed by removing excess metal from the bosses on the small-end
or big-end up to the minimum size of 16.5 mm or 35.5 mm (Fig.2-
pistons).
31).
The class number (5 in Fig.2-30) is engraved on the big-end
cap.
The connecting rod small-end and big-end are classified
weight-wise (Table 2-1) and are paint marked on the connecting

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Fig.2-30. Marking on the piston and connecting rod:

1 - arrow on piston crown for orientation in cylinder; 2 - oversize; 3 - piston class;
4 - class of gudgeon pin hole; 5 - connecting rod class as to gudgeon pin hole; Fig.2-31. Locations of possible metal removal subject to adjusted con-
6 - cylinder No necting rod small-end and big-end weights

22
 Table 2-1 Dismantling and reassembly
Connecting rod classification as to
Dismantling. Prise out the gudgeon pin circlips from the pis-
small-end and big-end weights ton, press out the gudgeon pin and detach the connecting rod
Connecting rod weight, g Class Paint mark from the piston. Remove the piston rings.
small-end big-end The bolts are pressed into the connecting rod and must never
be pressed out from the connecting rods during the engine or pis-
519±3 Ä white
ton/connecting rod dismantling.
186±2 525±3 Ç blue
When some components of the piston or connecting rod are
531±3 ë red not damaged or show little wear, they can be re-used. Identify
them accordingly during dismantling to facilitate further reassem-
519±3 D black bly with the respective components and to the original cylinder.
Reassembly. Before reassembly, select the gudgeon pin to
190±2 525±3 E violet
match the piston and connecting rod. For new components the
531±3 F green
class of the holes for the gudgeon pin in the connecting rod and
pistons must be identical to the class of the gudgeon pin. In case
519±3 G yellow of used components, for perfect mating, the gudgeon pin when
oiled should fit the relevant piston hole by force of the hand thumb
194±2 525±3 ç brown
(Fig.2-32); it should not drop out while held as shown in Fig.2-33.
531±3 I orange

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If the gudgeon pin drops, replace it with a new one of the next
class. When the piston is fitted with the gudgeon pin of the third
Selecting piston to cylinder class, renew the piston, gudgeon pin and connecting rod.
The design clearance between the piston and cylinder bore The reassembly of the piston and connecting rod is a rever-
(for new parts) is 0.025 - 0.045. The condition must be ensured sal of dismantling. After reassembly oil the gudgeon pin through
through prior measurements of the associated parts and fitting of the holes in the piston bosses. Refit the piston rings in the order
the pistons which belong to the same class of cylinders. The max- as detailed below.
imum permissible gap (for worn parts) is 0.15 mm. Oil the piston rings and grooves in the piston. Arrange the pis-
When the engine, in the course of operation, shows a clear- ton rings so that the gap of the first compression ring is at a 45°
ance of over 0.15 mm, reselect the pistons to the cylinders to interval to the gudgeon pin; space the gap of the second com-
have the clearance as close to the design value as possible. pression ring at about 180° interval to the first compression gap,
afterwards align the gap of the oil ring at about 90° interval to the
The pistons of classes Ä, ë, Ö are intended for replacement.
first compression ring gap.
These classes can be selected to closely match any cylinder in
the event of the engine overhaul, since the pistons and cylinders
are classified with small overlapping in the sizes. It means, the
piston of class C can match the cylinders of class B and D.

Fig.2-32. Fitting the gudgeon pin using the thumb pressure Fig.2-33. Checking the gudgeon pin fitting

23
 0.02-0.05 mm for the oil control ring. When worn, the tolerance
must not exceed the specified maximum of 0.15 mm.
The piston ring gap should be checked with a feeler gauge
via inserting the rings into the gauge (Fig.2-35), with the bore
equal to the piston ring nominal diameter ±0.003 mm. Use gauge
67.8125.9502 for the normal 82 mm rings.
The gap for all new piston rings should be within 0.25 to 0.45
mm. The maximum permitted gap for worn rings is 1 mm.

Crankshaft and flywheel

Design description
Basic dimensions of the crankshaft are shown in Fig.2-36.
Fig.2-34. Checking the piston ring-to-groove gap
Crankshaft is cast-iron, of five bearings. The crankshaft
journals can be reground during the engine overhaul when the
diameter is reduced by 0.25 mm, 0.5 mm, 0.75 mm and 1mm.
The crankshaft endfloat is restricted by two thrust washers.

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The thrust washers are fitted on both sides of the rear main bear-
ing: a sintered one (yellow) at the rear end and a steel-aluminium
one at the front end. The thrust washers are of two sizes - stan-
dard and 0.127 mm thicker.
Crankshaft bearing shells are thin-walled, aluminium with
steel backing. The upper bearing shells of No 1, 2, 4 Ë 5 bearings
have inner oil grooves, whilst the lower bearing shells are plain
shells. The upper and lower bearing shells of the centre bearing
(No 3) are plain, without an oil groove. The big-end bearing shells
(both upper and lower ones) are also plain.
The oversize bearing shells are thicker for the crankshaft
Fig. 2-35. Checking the piston ring gap
journals reduced by 0.25 mm, 0.5 mm, 0.75 mm and 1 mm.
Make certain the second compression ring is positioned with Flywheel is cast iron with the pressed-in steel starter ring.
the recess facing down (Fig.2-30), while the TOP (or ÇÖêï) mark The flywheel centering is ensured by a front input shaft bearing
should face up (the piston crown). which is pressed into the crankshaft.
Before refitting the oil ring, check to see the joint of the coil A taper recess on the rear face of the flywheel near the ring
expander (spreader ring) is on the side opposite to the ring gap. gear is provided as a positioning mark. Adjust it against cylinder
No 4 crankpin.
Inspection
Inspection and overhaul
Scrape away all traces of carbon from the piston and remove
all carbon deposits from the piston/connecting rod oilways. Crankshaft. Inspect the crankshaft. Make sure there are no
cracks. Examine the faces which mate the oil seal working edges
Thoroughly examine the components. Make sure there are
for evident cracking, scoring or scuffing.
no cracks of any sort on the piston, piston rings, gudgeon pin,
Mount the crankshaft on two V-blocks as shown in Fig.2-37
connecting rod or big-end cap. Renew the bearing shell if there
and check the run-out with a dial gauge:
is obvious scoring or scuffing.
• main bearing journals - maximum 0.03 mm;
The piston-ring-to-groove wall clearance is checked using
feeler blades as shown in Fig.2-34, fitting the ring into the respec- • mounting surfaces for the input shaft sprocket and bearing
tive groove. For new components the design clearance (rounded - maximum 0.04 mm;
off to the nearest 0.01 mm) is 0.04-0.07 mm for the first com- • surface mating the oil seal - maximum 0.05 mm.
pression ring; 0.03-0.06 mm for the second compression ring and Measure the diameters of the main bearing journals and

24
 cardiagn.com
Fig.2-36. Basic crankshaft dimensions

crankpins. Regrind when the wear is in excess of 0.03 mm, oval-

ity is over 0.03 mm, or when scoring and scuffing is obvious.
Regrind the journals and crankpins through reducing the
diameter to the nearest undersize (Fig.2-36).
When regrinding, observe the sizes for the crankshaft fillet as
shown in Fig.2-36 for the standard-size crankshaft.
The ovality and taper for the main bearing journals and big-
end bearing journals after regrinding must not exceed 0.005 mm.
On a reground crankshaft, the vertical offset of the crankpins Fig.2-37. Permissible runouts for basic crankshaft surfaces
axes must be 0.35 mm (Fig.2-37). To check this, place the crank-
shaft on V-blocks and position the crankshaft so that No1 The main and big-end bearing running clearance is checked
crankpin axis is in the horizontal plane passing through the main by measuring the components. It is convenient to check the
bearing journal axes. Using a dial gauge, check the vertical off- clearance with the help of «Plastigage» (which consists of a fine
set of crankpins No 2, No 3 and No 4 against crankpin No 1. thread of perfectly-round plastic, which is compressed between
the bearing cap shell and the crankshaft journal) under the fol-
After regrinding the journals and crankpins, polish them using
lowing procedure:
the diamond paste or special grinding pastes.
- ensure the journals and bearing shells are clean and dry,
After regrinding and followed finishing, unplug the oilways,
cut several pieces of the appropriate-size Plastigage (they should
then machine the plug seats with the mill-cutter Ä.94016/10 and
be slightly shorter than the width of the bearings) and place one
spindle Ä.94016. Thoroughly wash the crankshaft and oilways to
piece on each crankshaft journal axis;
flush abrasive residuals and blow dry with compressed air.
- with the bearing shells in position in the cages, fit the caps to
Use tool Ä.86010 to press in new plugs and punch each plug their original locations (depending on the journal checked). Take care
in three points with a centre-punch. not to disturb the Plastigage. Then tighten the securing nuts and bolts
On crankshaft web No 1 mark the reduced amount (under- to the specified torque. Tighten the connecting rod bolts to 51 ç•Ï
size) of the main bearing journals and big-end journals (eg. M (5.2 kgf•m), while the main bearing cap bolts to 80.4 ç•Ï (8.2 kgf•m);
0.25; B 0.50). - remove the bearing cap and check the running clearance by
Bearing shells. Remember that no adjustment on the bear- comparing the width of the crushed Plastigage on each journal
ing shells is allowed. Renew the shells when there are scratches, with the scale printed on the card gauge to obtain the bearing
scoring or flaking. running clearance (Fig.2-38).

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 cardiagn.com
Fig.2-38. Measuring the big-end bearing running clearance: Fig.2-39. Flywheel:
1 - crushed Plastigage; 2 - bearing shell; 3 - big end cap; 4 - scale for clear- 1 - surface mating the crankshaft flange; 2 - surface for clutch securing; 3 -
ance measurement clutching surface

The nominal design clearance is 0.02-0.07 mm for the starter ring interference on the flywheel. The starter ring should
crankpins and 0.026-0.073 mm for the main bearing journal. not rotate when applying 590 ç•Ï (60 kgf•m).
When the running clearance is below the maximum value (0.1 Check to see there are no scratches or scores on flywheel
mm for the big-end bearing journals and 0.15 mm for the main face 1 mating the crankshaft flange or on surface 3 mating the
bearing journals), the bearing shells can be re-used. clutch disc.
When the running clearance exceeds the specified maxi- Remove by lathing all scratches or scores on face 3, provid-
mum, replace the respective bearing shells with new ones. ed the overall thickness is reduced maximum by 1 mm. Do not
Where the crankshaft journals are worn and are reground to forget to lathe surface 2 maintaining the size (0.5±0.1) mm.
their undersize, change the bearing shells to those oversize. Ensure surfaces 2 and 3 are parallel to surface 1. The out-of-par-
Thrust washers. Similar to the bearing shells, no adjust- allelism tolerance is 0.1 mm.
ments are possible on the thrust washers. Always renew the Mount the flywheel on the tool, centralize is over the mount-
thrust washers when there is scoring, scuffing or flaking. ing bore against surface 1 and check the run-out of surfaces 2
and 3. The run-out values at the outboard points must not exceed
The thrust washers must be renewed when the crankshaft
0.1 mm.
endfloat exceeds the specified limit of 0.35 mm. Select new thrust
washers of the standard size or 0.127 mm thicker to have the
endfloat within 0.06 - 0.26 mm.
The crankshaft endfloat is checked with the help of a dial
Cylinder head and valve gear
gauge as outlined in Section «Engine reassembly» (Fig.2-14).
General description
The crankshaft endfloat can be also checked on the engine in
the vehicle. The axial shift of the crankshaft occurs at depressing Refer to Fig. 2-40 for basic sizes of the valves, guides and
and releasing the clutch pedal, the endfloat value is determined valve seats.
by the front crankshaft end displacement. Cylinder head is an aluminium casting with the pressed-in iron
Flywheel. Inspect the teeth of the flywheel starter ring, valve seats and valve guides.
should they are found deteriorated, renew the flywheel. If there The top of the valve guides is sealed with metal-rubber oil caps
are temper colours on flywheel face 3 (Fig.2-39), check the 3 (Fig.2-41).

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 cardiagn.com
Fig.2-40. Basic dimensions of the valves, valve guides and valve seats

The outer diameter of the replacement guides is 0.2 mm big-

ger. Bearing housing 5 with camshaft 6 is fitted to the cylinder
head.
Valve train. Valves 2 are operated by the cams through
levers 4. One end of the lever pushes the valve stem, while the
other end rests on the spherical head of adjuster bolt 7 which
adjusts the clearance A in the valve gear.

Valve clearance adjustment

The clearances are adjusted on the cold engine by means of
the chain adequately tensioned. The adjustment should result is
0.15±0.02 mm clearance for the intake valves and 0.2±0.02 mm
clearance for the exhaust valves.
While making adjustments, do not to twist the valve lever,
since it may result in a bigger final clearance.
The clearance is adjusted as follows:
- turn the crankshaft clockwise to align the indentation in the
camshaft sprocket with the mark on the bearing housing, which
corresponds to the end of the compression stroke of the cylinder
No4. Now in this position adjust the clearance at the cylinder No4
exhaust valve (No8 cam) and cylinder No3 intake valve (No6 cam);
- slacken the valve lever adjuster bolt nut;
Fig.2-41. Cylinder head cross-sectional view showing the exhaust valve: - between the valve lever and cam place a flat feeler blade
1 - cylinder head; 2 - valve; 3 - oil cap; 4 - lever; 5 - bearing housing; 6 - (A.95111) of 0.15 mm for the intake valve (0.2 mm for the exhaust
camshaft; 7 - adjuster bolt; 8 - lock nut; Ä - cam-to-lever clearance valve) and using a spanner tighten or slacken the bolt with further

27
Fig.2-42. Checking the clearance between the rocker levers and cam
lobes:
1 - feeler blade Ä.95111; 2 - adjuster bolt; 3 - lock nut

lock nut tightening, until the blade is a firm sliding fit when the lock

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nut is tightened (Fig.2-42);
- after the clearance is adjusted at the cylinder No4 exhaust
valve and cylinder No3 intake valve, turn the crankshaft progres-
Fig.2-43. Valve components:
sively to the 180° and adjust the clearances, observing the 1 - valve; 2 - circlip; 3 - valve guide; 4 - oil cap; 5 - lower spring seat, outer
sequence as shown in Table 2-2. spring; 6 - locking washer, inner spring; 7 - inner spring; 8 - outer spring; 9 -
upper spring seat; 10 - collets; 11 - valve rocker lever; 12 - valve lever spring;
13 - adjuster bolt; 14 - lock nut, adjuster bolt; 15 - bush, adjuster bolt; 16 - lock-
Table 2-2 ing plate, valve lever spring

Valve clearance adjustment

Crankshaft angle, Cylinder No Valve (cam) No
degrees (end of compression stroke)

0 4 8&6

180 2 4&7

360 1 1&3

540 3 5&2

Cylinder head - removal and refitting Fig.2-44. Removing the valve spring:
1 - tool Ä.60311/R; 2 - mounting base
The cylinder head is removed from the engine in the vehicle,
when no complete stripping of the engine is required, or when
carbon deposits should only be removed from the combustion
chamber and valves. To remove the cylinder head, carry out the
following operations.
Apply the handbrake, remove the spare wheel and discon-
nect the battery negative lead.
Remove the air cleaner and protect the carburettor with the
provisional plug. Drain the coolant from the radiator and cylinder
Fig. 2-45. Checking the leak-proofness of the cylinder head on tool
block. A.60334:
1, 2, 4 - plugs; 3 - tool plate; 5 - flange with water supply connector

28
 Disconnect the leads from the spark plugs and coolant tem- Slacken lock nuts 14, undo adjuster bolts 13 and bushes 15.
perature sender, from carburettor idle switch and fuel cutoff sole- Position tool Ä.60311/R, as shown in Fig.2-44, compress the
noid. valve springs and release the collets. A stationary tool
Disconnect the choke cable; disconnect the throttle linkage 02.7823.9505 can be used instead of tool Ä.60311/R.
from the intermediate lever on the valve cover. Remove the valve springs together with lower and upper
Loosen the clips and disconnect the carburettor supply / seats. Turn the cylinder head over and remove the valves from
return fuel hoses. Secure the hoses in a manner to exclude pos- the underneath. Take off the outer caps from the valve guides.
sible fuel leaks. Detach the vacuum hose from the carburettor. Reassembly. Reassemble the cylinder head in the reverse
Disconnect the hoses from the intake pipe, from the outlet order. Before assembly begins, always oil the outer caps and
pipe of the cooling water jacket and from coolant delivery pipe to valves with engine oil.
the heater. Remove the EGR valve. Before refitting the camshaft bearing housing, check the cen-
Disconnect the starter motor shield from the exhaust mani- tering pins are in the position (Fin.2-21). Tighten the bearing
fold, downpipe and detach the bracket securing the coolant pipe housing securing nuts in the sequence as shown in Fig.2-23.
(heater return line). Ensure the centering pins are positioned in the bearing housing
Remove the valve cover complete with the gasket and fuel recesses without sheering.
piping securing bracket. The valve clearances are adjusted only after the cylinder
Turn the crankshaft to align the camshaft sprocket TDC mark head has been refitted to the engine.
against the bearing housing mark (Fig.2-22).
Inspection and overhaul

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Unbolt the camshaft sprocket. Slacken the chain tensioner
cap nut, release the tensioner rod and fix it in position with the Cylinder head. Thoroughly wash the cylinder head and
cap nut. Remove the camshaft sprocket. clean the oilways. Scrape away all carbon from the combustion
Undo the bolts securing the cylinder head to the cylinder chambers and from the exhaust valve ports with a wire brush.
block and remove the cylinder head complete with the gasket. Examine the cylinder head. Look to see there is no cracking
Refitting of the cylinder head is the reverse order of removal, in the cylinder head. Check the cylinder head for leakage when
refer to the procedure described in section «Engine reassembly». suspicious as to possible oil contamination with coolant.
Never re-use the gasket between the cylinder head and cylinder To do this, plug the cooling water jacket holes (using plugs
block, always replace it with a new one. from tool A.60334, Fig.2-45), then pump water into the cylinder
While refitting the cylinder head, adjust the timing chain ten- head water jacket at 0.5 åP‡ (5 kgf/Òm2). No water leak should
sion and valve clearances. Having refitted the cylinder head, be evident within 2 minutes.
adjust the carburettor linkage and ignition timing. The cylinder head tightness can be checked with compressed
air. Plug the water jacket holes (using the same plugs from tool
Cylinder head - dismantling and reassembly Ä.60334), immerse the cylinder head into the bath with water of
60-80°C for 5 minutes. Next pump the compressed air into the
Dismantling. When only a single part is required to be cylinder head at 0.15-0.2 åPa (1.5-2 kgf/Òm2). No air bubbles
replaced, there is no need to completely dismantle the cylinder must be seen from the cylinder head within 1-1.5 minutes.
head; instead, remove only what is necessary.
Valve seats. The valve seat chamfer shape is shown in
Position the cylinder head on the stand, disconnect the hose Fig.2-46 and Fig.2-47. Check the working chamfers of the valve
from the hot air intake, undo the nuts and remove the carburettor seats (valve contact area) for pitting, corrosion or deterioration.
complete with the gasket; next withdraw the inlet and exhaust Minor irregularities of the seats must be recut. Remove as little
manifolds (the hot air intake is withdrawn at the same time). metal as possible. Both manual and machine grinding is permit-
Remove the water jacket return pipe and coolant-to-heater ted. Valve regrinding is carried out as follows.
return pipe. Unscrew the spark plugs and coolant temperature Position the cylinder head on a mounting base. Insert cen-
sender. tering tool A.94059 in the valve guide and clean the seat cham-
Undo the securing nuts and remove the bearing housing fers from carbon using tools Ä.94031 and Ä.94092 for the
complete with the camshaft. Undo the nuts holding the thrust exhaust valves and Ä.94003 and Ä.94101 for the inlet valves.
flange to the bearing housing. Remove the flange and lift out the Use spindle Ä.94058 and centering tool Ä.94059. The centering
camshaft from the bearing housing. tools differ in diameters, use tool Ä.94059/1 for the inlet valve
Release springs 12 and remove valve rocker levers 11 guides and Ä.94059/2 for the exhaust valve guides.
(Fig.2-43). Remove the rocker lever springs.

29
Fig. 2-46. Intake valve seat profile: Fig. 2-47. Exhaust valve seat profile:
I - new seat; II - reconditioned seat I - new seat; II - reconditioned seat

Put spring A.94069/5 on tool Ä.94059, fit tapered wheel

A.94078 on spindle Ä.94069 for the exhaust valve seats or wheel

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Ä.94100 for the inlet valve seats, secure the spindle in a grinder
and recut the valve seat (Fig.2-48).
The grinding wheel must be off at the moment the grinding
wheel contacts the valve seat, otherwise vibration ensued will dis-
tort the chamfer. Frequent diamond dressing of the wheel is rec-
ommended.
The working chamfer width for the exhaust valve seats should
be as shown in Fig.2-46 using tools A.94031 (20°) and A.94092
to remove the wear hardening on the minor diameter. The tools
should be used with spindle Ä.94058 and are centered with tool
Ä.94059.
The working chamfer width for the inlet valve seats should be
as shown in Fig.2-47, first machine the inner chamfer with tool
Ä.94003 (Fig.2-49) to get the diameter of 33 mm, then machine
the 20° chamfer with tool Ä.94101 to achieve the working cham- Fig. 2-48. Regrinding the valve seat working chamfer
fer width of 1.9-2 mm.
Valves. Scrape away carbon from the valves.
Check the valve stem for deformation; check the valve disc
for cracking. Always renew the damaged valve.
Examine the valve working chamfer. Reface the valve in case
of minor damages, maintaining the chamfer angle at 45°30'
±5'. Note, that the distance between the bottom valve seat face
and base diameter (36 and 30.5) must be as shown in Fig.2-50.
Valve guides. Check the valve guide - to - stem clearance by
measuring the valve stem diameter and valve guide bore.
The clearance for new guides is 0.022 - 0.055 mm for the inlet
valves and 0.029 - 0.062 mm for the exhaust valves; the maxi-
mum permissible clearance (in case of wear) is 0.3 mm provided
no excessive noise is produced in the valve train. Fig. 2-49. Reducing the valve seat working chamfer using the cutting tool
with spindle Ä.94058

30
Fig.2-50. Limit sizes for valve chamfer regrinding: Fig.2-53. Valve spring checking diagram:
I - inlet valve; II - outlet valve Ä - dimension in free state; Ç - dimension under load

When a new valve fails to take up clearance between the

valve guide and the valve rim, renew the valve guides using tool

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Ä.60153/R (Fig.2-51).
Push in the valve guide complete with the circlip to the cylin-
der head to their stop.
After the valve is pressed into position, ream the valve guide
bores using tool Ä.90310/1 (for the inlet valve guides) and tool
Ä.90310/2 (for the exhaust valve guides).
Valve stem oil caps must always be renewed during the
engine overhaul.
Any damaged oil caps are renewed on the cylinder head
removed. Use special tool 41.7853.4016 to push the oil seals on
the guide.
Springs. Check the springs are not cracked and are ade-
quately tense; load test the springs to reveal any deformation
Fig.2-51. Pressing out the valve guides: (Fig.2-52).
1- tool Ä.60153/R

Fig.2-52. Basic lengths to check the valve outer (a) and inner (b) springs

31
 For lever springs (Fig.2-53) the size Ä (spring unloaded) In order to eliminate the camshaft endfloat, the camshaft is
must be 35 mm, whereas the size Ç (spring loaded 51-73.5 N/ supported by the thrust flange held in the front journal groove.
5.2-7.5 kgf) must be 43 mm. Camshaft is operated through crankshaft sprocket 5 (Fig. 2-
Cylinder head bolts. Multiple use of the cylinder head bolts 55) and double-row roller chain 2. The chain also operates
results in the bolt elongation. Therefore, check the length of the sprocket 4 of the oil pump shaft. The chain drive has semi-auto-
bolt (L) to be 120 mm (less the bolt head length), otherwise matic tensioner 8 with shoe 7 and chain damper 3 with rubber
renew the bolt. covers.
When replacing the bolts take care not to fit similar bolts from In the cylinder bottom there is stop pin 6 to prevent the chain
other VAZ engines of the same type (2101, 21011, 2103, 2107, dropping into the crankcase when camshaft sprocket 1 is
2121), but made of different steel. removed.
The 21213 engine bolts have the threaded area of 70 ÏÏ (30
mm for other engines); in addition, the 21213 engine bolts do not Chain tension adjustment
have a distinctive mark (a 7.5 mm diameter recess for wrench). Loosen nut 1 (Fig.2-56) of the tensioner. This releases rod 3
Valve rocker levers. Check the condition of the lever oper- and the chain is tightened by means of shoe 7 (Fig.2-55) which
ating surfaces which mate the valve stem, cam lobe and adjuster is loaded by spring 7 (Fig.2-56).
bolt spherical end. Turn the crankshaft 1-1.5 turns progressively. By doing that,
Always renew the rocker arm when its surfaces are chipped, the tensioner spring, operating the shoe, automatically adjusts the
scored or scuffed. chain tension.

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Renew the lever adjuster bolt bush or the bolt itself in case of Tighten tensioner nut 1, this results in rod 3 clamped by col-
any deformation or damages found. lets 8; during engine operation plunger 6 is effected only by
spring 4. The spring releases the plunger from rod 3 head, so that
the clearance between them is filled with oil that acts as a
Camshaft and timing gear damper when the chain strikes.

Design description Chain renewal

Camshaft is cast iron, of five bearings, operates in the alu- Apply the handbrake, open the bonnet, remove the spare
minium bearing housing fitted to the cylinder head. wheel with the supporting tube and withdraw the battery.
Basic dimensions of the camshaft and bearing housing are Remove the air cleaner and close the carburettor inlet filler
shown in Fig.2-54. The flanks of the cams are chilled for better with a provisional cap. Disconnect the throttle and choke cables
wear resistance. from the carburettor.

Fig2-54. Basic dimensions of the camshaft and the bearing housing

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 Fig.2-56. Sectional view of the chain tensioner:
1 - cap nut; 2 - tensioner housing; 3 - core; 4 - spring; 5 - washer; 6 - plunger;
7 - spring; 8 - collet; 9 - spring ring;

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Ä - plunger surface; Ç - centre-punch points on housing face

Before refitting, smear the chain with engine oil. Always use new
gaskets for the timing cover and valve cover.
The chain refitted, adjust the chain tension and alternator dri-
vebelt tension, adjust the carburettor linkage and ignition timing.

Inspection
Fig.2-55. Camshaft and ancillaries drive:
1 - camshaft sprocket; 2 - chain; 3 - chain damper; 4 - oil pump shaft Camshaft. The camshaft journals must have no scores,
sprocket; 6 - stop pin; 7 - tensioner shoe; 8 - chain tensioner scuffs, scratches or aluminium galling from the bearing housing.
The maximum wear of the cam lobe surfaces is 0.5 mm, there
Drain the cooling water from the radiator and cylinder block, should be no evident scoring or cut-type wear of the cams.
remove the radiator complete with the hoses and thermostat.
Mount the crankshaft on two V-blocks, located on the test
Undo the retaining nuts and remove the fan.
plate and using a dial gauge, check the centre camshaft journal
Remove the valve cover and turn the crankshaft to align the
endfloat to be 0.04 mm maximum. If the endfloat exceeds the
TDC mark in the camshaft sprocket against the timing mark in the
value specified, straighten the camshaft on the straightening
bearing housing (Fig.2-21), while the alternator belt pulley marks
press.
are aligned against a long mark in the timing cover (Fig.7-18).
Undo the camshaft sprocket retaining bolt. Slacken the chain
tensioner cap nut, release the tensioner rod and fix it in position
using the cap nut. Remove the camshaft sprocket.
Slacken the alternator and remove the alternator drivebelt.
Apply the 4th gear of the gearbox, undo the nut and withdraw the
alternator drivebelt pulley from the crankshaft.
Remove the timing cover complete with the gasket. Undo the
nuts holding the cover to the cylinder block; then undo the bolts
retaining the oil sump to the cover.
Undo stop pin 6 (Fig.2-55) and withdraw the camshaft timing
chain.
The refitting procedure is a reversal of removal, observing
the recommendations outlined in section «Engine assembly». Fig.2-57. Basic data for checking the tensioner spring

33
 The spring tension should be within the range specified in
Fig.2-57; otherwise renew the spring.
Check to see the shoe and chain damper do not have excess
wear; renew them when applicable.
Refitting is a reversal of removal. Once the plunger is refitted,
center-punch housing 2 at three points B. Make certain the pro-
jections caused by centre-punching do not contact the surface A
during the plunger stroke.
Note: The spring ring is used in some vehicles instead of
centre-punching.
Camshaft timing chain. Wash the chain in kerosine, exam-
ine the chain links. Check to see there are no scores, cracks or
other damages.
Fig. 2-58. Tool 67.7824.9521 for checking the chain wear (extension):
1 - roller; 2 - adjuster nut; 3 - counterweight In the course of the engine operation the chain lengthens.
The chain deems operable as long as the tensioner ensures its
proper tension, i.e. the chain length is maximum 4 mm longer.
Check the chain length with the help of tool 67.7824. 9521
(Fig.2-58), having 2 special-type wheels 1 on which the chain is

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located. Using counterweight 3 the chain is extended through
applying force of 294 N (30 kgf) or 147 N (15 kgf). Use adjuster
nut 2 to ensure the counterweight axis is parallel to the tool base.
Apply force 294 N (30 kgf) with the counterweight in the
extreme right position, then decrease the force by 147 N (15 kgf)
moving the counterweight fully to the left. Repeat both operations
and determine the chain difference on the length L (Fig.2-59)
between the axis of the wheels. Using vernier calipers, measure
the distance between the wheels, then add the diameter d value
to get the distance L between the wheels axes.

Fig.2-59. Checking the chain wear (extension):

For a new chain the distance L between the wheels axes is
1- pulleys 495.4-495.8 mm. Renew the chain, when its length is 499.5 mm.
Before refitting, smear the chain with engine oil.
Camshaft bearing housing. Wash and clean the bearing
housing, flush clean the oilways.
Check the diameters of the holes in the bearings. When the ëooling system
clearance between the camshaft journals and bearing surfaces
Refer to the cooling system layout as shown in Fig.2-60.
exceeds 0.2 mm (wear limit), renew the bearing housing.
The inner bearing surfaces should be smooth, with no scores;
Checking coolant level and density
renew the bearing housing in case of damages. Check the hous-
ing for cracks; if this is the case, renew the bearing housing. Check to make certain the coolant level in the expansion tank
Chain tensioner. When the tensioner plunger is seized in the is adequate. When the engine is cold (15-20°C), the coolant level
housing, dismantle the chain tensioner. For that undo cap nut 1 within the expansion tank must be 3-4 cm above the «MIN» mark.
(Fig.2-56), push plunger 6 full way, then tighten the cap nut. File
WARNING. Always check the coolant level on the cold
the housing edges at the points B of centre-punching, withdraw
engine, since its volume increases with rise in temperature;
plunger 6 with spring 4. Undo the cap nut and withdraw rod 3
the coolant level can be significantly higher with the hot
complete with spring 7 and washer 5. Prise free spring ring 9 and
engine.
take out clamping collet 8 from cap nut 1.
Check collet 8, core 3 and plunger 6 for scores, check the When necessary, use an areometer to check the coolant
mating surfaces of the tensioner shoe and plunger for deep density to be 1.078-1.085 g/cu.cm for TOSOL A-40 which is used
scores. Always renew any damaged components. in VAZ vehicles.

34
 When the level in the expansion tank is below the value spec- - disconnect the heater hose (top) from the union on the vehi-
ified, while its density is in excess of that required, top up distilled cle body;
water. - pour coolant (10.7 litre) to the radiator (up to the upper filler
When the density is as recommended, top up the correct edge) until it starts flowing from the hose and heater union;
coolant of the same grade as that in the cooling system. - reconnect the heater hose with the union and refit the radi-
When the coolant density is below the value specified, while ator cap. Top up the remaining coolant into the expansion tank,
the vehicle will be used in cold conditions, change the coolant. refit and tighten the filler cap;
- to remove air pockets, start the engine, run it idle until the
Coolant change coolant temperature reaches the temperature of the thermostat
opening (80±2)°C. Check to see the radiator inlet and return
Change coolant at the intervals recommended or after the pipes are hot.
engine overhaul. Fill the cooling system, as described below: Leave the engine to cool and check the coolant level. When
- undo the radiator and expansion tank caps, open the heater the level is below that required, while there are no evident sys-
tap; tem leaks, top up coolant as necessary.

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Fig.2-60. Engine cooling system:

1 - radiator return hose; 2 - thermostat; 3 - thermostat hose; 4 - return hose to pump; 5 - return pipe, heater radiator; 6 - delivery pipe, heater radiator; 7 - return hose
from intake manifold preheater to part throttle channel heater; 8 - part throttle channel heater; 9 - expansion tank; 10 - coolant temperature sensor; 11 - hose between
radiator and expansion tank; 12 - radiator feed hose; 13 - left-hand fluid cooler; 14 - radiator cap; 15 - radiator matrix; 16 - fan ring; 17 - radiator drain tap; 18 - radia-
tor mounting rubber; 19 - right-hand fluid cooler; 20 - water pump; 21 - feed hose to pump

35
 Fig.2-63. Removing the impeller:
Fig.2-61. Checking the water pump belt tension 1 - puller; 2 - impeller

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Fig.2-62. Sectional view of the coolant pump:

1 - pulley hub; 2 - shaft; 3 - cover; 4 - impeller; 5 - housing; 6 - thrust ring; 7 - oil seal; 8 - bearing stop screw; 9 - pulley; 10 - blower fan; 11 - cover plate; 12 - fan hub

36
Water pump drivebelt tension adjustment
The belt tension is checked by exerting a hand pressure on
the chain between the alternator pulley and pump pulley or
between the pump pulley and crankshaft pulley. With proper ten-
sion, slack A in the belt (Fig.2-61) at 98 N (10 kgf) must be 10-15
ÏÏ, while at the same pressure the deflection Ç must be within
12-17 mm.
To adjust the belt tension, slacken the alternator retaining nuts,
move the alternator off the engine (to increase tension) or towards
the engine (to decrease tension), then tighten the nuts. Turn the
crankshaft two revolutions clockwise and check the belt tension.
No excess tension of the belt is allowed to prevent hazardous
loads to the alternator bearings.

Coolant pump
Fig.2-64. Removing the pulley hub:
Dismantling. Carry out the coolant pump dismantling as 1 - pump housing cover; 2 - pulley hub; 3 - tool Ä.40005/1/5
detailed below:
- disconnect pump housing 5 (Fig.2-62) from cover 3;

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- place the cover in vice using protective pads; remove
impeller 2 (Fig.2-63) from the shaft using picker Ä.40026;
- remove hub 2 (Fig.2-64) of the fan pulley from the shaft
using puller Ä.40005/1/5;
- undo lock screw 8 (Fig.2-62) and force out the shaft with the
bearing, applying force to the bearing race;
- withdraw oil seal 7 from housing cover 3.
Inspection. Check the bearing axial clearance. This opera-
tion is mandatory if the pump is noisy. The clearance must not
exceed 0.13 mm at load of 49 N (5 kgf). Renew the bearing com-
plete with the shaft when the clearance is bigger.
Always remember to renew the pump oil seal and pump-to-
cylinder block gasket during overhaul.
Check the pump housing and cover for cracks or deformation,
which are not permitted.
Reassembly. The assembly is carried out as follows:
- using the appropriate tool, fit the oil seal to the housing
cover, look out not to skew; Fig.2-65. Fitting the impeller to the pump shaft using tool Ä.60430:
1 - base; 2 - pump shaft; 3 - pump housing cover; 4 - shell; 5 - set screw
- press in the bearing and shaft, applying the force to the
bearing race so that the holes for the locking screw are matched; - reassemble the pump housing with the cover, having placed
- tighten the bearing lock screw and punch the seat over the the gasket in-between.
contour to prevent its self-loosening;
- using tool Ä.60430 (Fig.2-65) press the pulley hub onto the Thermostat
shaft, maintaining a size of (84.4±0.3) mm. When the hub is of
To test whether the unit is serviceable, check the temperature
sintered quality, press in the new hub only.
of the main valve opening and valve travel.
- using tool A60430, press the impeller onto the shaft, main-
taining a size of (48-0,2) mm, as shown in Fig.2-62. This ensures Using the test bench Åë-106-000, suspend the thermostat
the required clearance between the impeller blades and pump with a piece of string in a container of water or coolant. Position
housing; the bracket arm of the gauge against main valve 9 (Fig.2-66).

37
 - disconnect the hoses from the radiator;
- separate the fan cowl halves and withdraw the fan cowl;
- undo two bolts holding the radiator to the body, release the
upper catch of the radiator cowling upwards, move the radiator
top towards the engine and withdraw the radiator from the engine
compartment;
- take out the radiator cowling.
Radiator leak test. The radiator tightness is checked in a
container full of water.
Plug the radiator pipes, apply air at pressure of 0.2 åPa (2
kgf/Òm2) and immerse the radiator into the water for at least 30
seconds. The radiator should show no air bubbles.
Repair or renew the radiator when it is found leaky or dam-
aged.
Radiator repair. In the event the aluminium tubes are dam-
aged, dismantle the radiator, drill the defective tubes from both
ends to a depth of 25-30 mm, using a drill of 8.5 mm diameter.
Fit the undersize tubes (flared at one end) of 7.3 mm diame-

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ter and 0.5 mm wall thickness into the defective tubes. Then on a
special stand push the tubes all the length down using a steel
Fig.2-66. Thermostat:
1 - intake manifold (engine side); 2 - relief valve; 3 - relief valve spring; 4 - shell;
core of 7.5±0.05 mm.
5 - rubber insert; 6 - exhaust manifold; 7 - main valve spring; 8 - main valve seat; On the respective bench expand each tube from both ends
9 - main valve; 10 - retainer; 11 - adjuster nut; 12 - piston; 13 - sleeve;
simultaneously.
D - coolant inflow from engine; ê - coolant inflow from radiator;
ç - coolant outflow to pump Assemble the radiator and check it for tightness.

Gradually heat the water from the starting 73-75°ë in incre- Lubrication system
ments of approximately 1°ë per minute, at constant agitation to
ensure homogeneous heating within the container. Refer to Fig.2-67.
The value, when the valve travel is 0.1 mm, is deemed as the
initial temperature of the main valve opening. Engine oil change
The main valve opening temperature is stated on the ther- Change oil only when the engine is hot. Allow at least 10 min-
mostat face side and is (80±2)°ë or (83±2)°ë. The thermostat is utes, after the drain plug is removed, for all the oil to drain.
subject to renewal when its main valve opening temperature dif-
Oil renewal should be accompanied by the oil filter removal;
fers from the value stated on the thermostat face or when the
use tool Ä.60312 (Fig.2-4) to undo the filter. When refitting, screw
main valve stroke is below 6.0 mm.
the filter into position on the engine and tighten the filter by hand
The easiest way to check the thermostat is serviceable, is to only - do not use any tools.
touch it directly in the vehicle. The thermostat is good when after
Change oil in the following order:
the engine cold start, the lower radiator pipe gets warmer as soon
as the coolant temperature reaches 80-85°C (the coolant tem- - stop the engine, drain the oil and without removing the oil fil-
perature gauge needle is 3-4 mm from the red area of the scale). ter, pour cleaner oil to the «MIN» mark of the oil dipstick (2.9 litre).
Use oil equivalent to grades Ççààçè-îÑ, åëè-1 or åèí-2å;

Radiator - start the engine and run it for 10 minutes at low rpm;
- completely drain the cleaner oil and discard the old oil filter;
Removal. Withdraw the radiator from the vehicle in the fol-
lowing order: - fit a new oil filter and pour oil of respective season grade.

- remove the spare wheel and its supporting tube;

Oil pump
- drain the fluid from the radiator and cylinder block through
the respective caps in the left-hand fluid cooler and cylinder block; The basic dimensions of the pump components and its link-
open the heater drain tap and remove the radiator filler cap; age are shown in Fig.2-68.

38
 cardiagn.com

Fig.2-67. Lubrication system:

1 - oil passage to main bearing; 2 - main bearing-to-big-end bearing oil passage; 3 - oil filter relief valve; 4 - paper element; 5 - check valve; 6 - oil pump; 7 - oil pump-to-
oil filter oil passage; 8 - oil passage from oil filter to main oil gallery; 9 - oil passage to oil pump gear and ignition distributor; 10 - oilway to oil pump shaft and ignition dis-
tributor; 11 - oil pump and ignition distributor shaft; 12 - oilway in outer gear to feed oil to chain; 13 - camshaft; 14 - oil recess, camshaft centre bearing journal; 15 - cam
lobe oilway; 16 - oilway, camshaft bearing journal; 17 - cylinder head vertical oil passage to valve timing gear; 18 - oil gallery; 19 - oil pressure warning light sender

39
 cardiagn.com
Fig.2-68. Basic dimensions of the oil pump components and associated parts

Removal and refitting. When only the oil pump requires recon- housing and cover for cracks, renew when applicable.
ditioning, remove it from the vehicle (Refer to section «Engine - Using feeler blades, check the backlash in the gears and the
removal and refitting»), place it on the turning stand, drain the oil radial play (Fig.2-70) to be respectfully 0.15 mm (maximum per-
from the sump, turn over the engine and remove the sump. Undo missible value is 0.25 mm) and 0.11-0.18 mm (maximum permis-
the oil pump bolts and remove the pump complete with the intake sible value is 0.25 mm). If the tolerances are exceeded, then the
manifold assembly. gears or pump housing should be renewed.
Refitting is the reversal order of removal. Using a feeler gauge and a straight-edge (Fig. 2-71), check
Dismantling and reassembly. Position the oil pump in vice the axial clearance to be 0.066-0.161 mm (maximum permissible
taking care not to damage the pump housing, then: value is 0.20 mm). When the clearance is over 0.20 mm, renew
- undo the bolts and remove the intake manifold complete the gears or pump housing whichever is worn out.
with the oil pressure relief valve; Having taken the measurements, determine the clearance
between the outer gear and its axle to be 0.017-0.057 mm (maxi-
- remove cover 3 (Fig.2-69) and withdraw the pump shaft
mum permissible value is 0.10 mm) and the clearance between the
complete with the inner and outer gears from the housing.
oil pump shaft and the housing bore to be 0.016-0.055 mm (maxi-
To reassemble the pump, position the pump in vice and carry
mum permissible value is 0.10 mm). Renew any worn parts when
out the following operations:
the tolerances exceed the values specified.
- refit the inner gear with the shaft, then the outer gear; Checking the pressure relief valve. Always inspect the
- refit the pump cover, pressure relief valve with the spring and pressure relief valve during the oil pump repair. Draw special
bolt the intake manifold assembly to the pump body. attention to the valve surfaces and bores in the intake manifold
assembly, since possible contamination or sediments on the mat-
Note. On completing the pump assembly, turn the inner gear ing surfaces can result in the valve seizures.
by hand to check the gears are running smoothly, without jerks or
The mating valve/pump cover surfaces should show no dents
seizures.
or flash to prevent a drop of oil pressure in the lubrication system.
Inspection. After dismantling, wash all components in kero- Check the relief valve spring tension against the values as
sine or petrol, blow dry with compressed air, then check the pump given in Fig.2-72.

40
Fig.2-69. Dismantling the oil pump:

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1 - relief valve; 2 - valve spring; 3 - cover; 4 - housing; 5 - shaft Fig. 2-70. Checking the oil pump radial play

Oil pump shaft and drive gears

Check to see there is no denting or scuffing of the shaft bear-

ing journals or eccentric cam surfaces.
No pitting of the oil pump gears or ignition distributor is per-
mitted, if this is the case, renew the gears and shaft.
Oil pump shaft bushes. Check the inner diameter of the
bushes, their proper fitting, make certain the oil port in the front
bush is aligned against the oilway in the cylinder block (bush turn-
ing). The inner surface must be smooth and without scuffs.
Measure the diameter of the shaft and bushes to determine
the clearances between the bushes and shaft bearing surfaces.
When the clearance is over 0.15 mm (limit wear value), or in case
of damaged or loose bushes, renew the bushes.
For removal and refitting use tool Ä.60333/1/2 (Fig. 2-73), Fig. 2-71. Checking the oil pump endfloat

observing the following:

- the bushes must be pressed in place with the oil port in the
front bush aligned against the oilway in the cylinder block;
- after pressing in, the bushes are machined to the final inner
diameter (Refer to Fig.2-68 for the sizes). For optimum concentric-
ity of the shaft bushes, use the finishing reamer Ä.90353 for con-
current machining of both bushes.
Oil pump inner gear bush. Check the bush is adequately
pressed in. The inner surface should be smooth, with no scuffs,
otherwise renew the bush.
Use tool Ä.60326/R for bush pressing-in or out (Fig.2-74).
After pressing-in, ream the bush to 16.016-16.037 mm. Fig.2-72. Basic data for checking the relief valve spring

41
Fig.2-73. Removal and refitting of the oil pump / distributor shaft bush:
1 - tool Ä.60333/1/2

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Fig.2-75. Crankcase ventilation diagram:
1 - filter element, air cleaner; 2 - exhaust manifold; 3 - flame arrester; 4 - hose
to draw crankcase emission on throttle body; 5 - discharge hose; 6 - oil sepa-
rator cover; 7 - oil separator; 8 - oil separator drain tube

Crankcase emission ventilation system

Flushing the system. For flushing disconnect vent hoses 4
and 5 (Fig. 2-75) from the manifolds, remove flame arrester 3
from discharge hose 5, remove cover 6 of oil separator 7 and
wash them in petrol or kerosine.
Flush and blow dry with compressed air the carburettor man-
Fig.2-74. Pressing out the oil pump / distributor inner gear bush: ifold to draw crankcase emission on the throttle body (to the side
1 - tool Ä.60326/R
of the air cleaner).

42
Fig.2-76. Air cleaner and temperature regulator:
1 - gasket; 2 - corrugated hose; 3 - air temperature control flap handle; 4 - cold
air intake; 5 - temperature regulator; 6 - clamp bolt; 7 - air cleaner cover secur-
ing nut; 8 - air cleaner cover; 9 - air cleaner cover gasket; 10 - filter element;
11 - filter cover mounting bracket; 12 - emission discharge pipe; 13 - air filter
housing; 14 - spring retainer; 15 - warm air intake from exhaust manifold Fig.2-77. Refitting the air cleaner cover

Fuel system Thoroughly examine the fuel tank welding seam for leaks. If
leakage is evident, solder the fuel tank.

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Air cleaner and temperature regulator WARNING. Before soldering, check to see the fuel tank
Removal and refitting. To remove the air cleaner, release is thoroughly cleaned and steam-treated and there are no
spring retainers 14 (Fig. 2-76) and undo nut 7 securing air clean- fuel vapours which can ignite and explode during soldering.
er cover 8. Remove the cover and lift out filter element 10.
Undo the nuts holding housing 13 to the carburettor. Fuel pump
Disconnect hose 2, then remove the air cleaner and temperature
regulator 5. Refer to Fig.2-79.

Loosen clamp bolt 6 and remove temperature regulator 5 Fuel pump inspection. Insufficient fuel flow to the carburet-
complete with cold air intake 4. tor can be caused by a faulty fuel pump, clogged or damaged fuel
lines or fuel filter.
When refitting the air cleaner, position the arrow on the filter
cover as shown in Fig. 2-77 in order to reduce intake air noise. To find the cause of failure, disconnect the hose from supply
manifold 1 and using fuel priming lever 8, check fuel delivery. If
there is no fuel, disconnect the hose from intake manifold 4 and
Fuel tank
check the manifold for vacuum. In case of vacuum, the fuel lines
Removal and refitting. Before removing fuel tank 1 (Fig.2- are damaged, if not - the fuel pump is faulty.
78), disconnect the battery earth lead. The fuel pump can be tested on a stand. By rotating the drive
Undo cap 5 of filler pipe 4 and remove as much petrol as pos- shaft at 2000±40 rpm, check the fuel delivery by the pump to be
sible. at least 54 litre/hour at 20±5°ë, while the supply pressure at
Remove the rear seat, undo screws holding the right-hand «zero» fuel delivery must be 0.02-0.03 åP‡ (0.21-0.30 kg/cm2 ).
and left-hand wheel arch liner, remove the liners. When found defective, dismantle the fuel pump and examine all
its components.
Unbolt and remove the cover in the floor to expose the fuel
tank. Disconnect hoses 9 and wiring from fuel level sender 8, fol- Dismantling, cleaning and inspection. To dismantle,
lowed by hoses 2 from the fuel vapour separator. unbolt cover 5, remove the cover and fuel pump filter 2. Next
undo the screws holding the housing to the lower cover, separate
Undo the retaining bolts and withdraw the petrol tank.
them, withdraw the diaphragm unit and spring. Wash all compo-
The fuel tank refitting is a reversal of removal. nents in petrol and blow dry with compressed air.
Cleaning and inspection. Remove the fuel level sender. Examine the state of components. The pump springs must
Clean the tank with petrol to remove any contaminants or sedi- be undamaged. Check the valves are not sticking. The
ments. Wash the tank with a jet of hot water and steam out any diaphragms must have no fractures, cracks or hard spots.
petrol residuals.

43
 cardiagn.com
Fig.2-78. Fuel tank and fuel pipeline associated components
1 - fuel tank; 2 - hoses, fuel vapour separator and fuel tank; 3 - fuel vapour separator; 4 - filler pipe; 5 - cap; 6 - hose, fuel tank and filler pipe; 7 - hose, fuel vapour sepa-
rator and fuel tank cover; 8 - fuel level sender; 9 - connection hoses; 10 - grommet; 11 - return flow line; 12 - fuel line; 13 - hose clips; 14 - non-return valve; 15 - carbu-
rettor; 16 - fuel pump; 17 - fine fuel filter

Fig.2-79. Fuel pump:

1 - delivery pipe; 2 - filter; 3 - housing; 4 - suction pipe; 5 - cover; 6 - suction valve; 7 - operating rod; 8 - hand priming lever; 9 - spring; 10 - eccentric; 11 - rocker; 12 -
mechanical priming lever; 13 - lower cover; 14 - inner distance gasket; 15 - outer distance gasket; 16 - delivery valve

44
 Check and renew any worn components. Always fit new pump
gaskets, remember to lubricate the gaskets with a thin layer of
grease before refitting them to the pump.

Refitting pump to engine. For correct fitting, use two out of

three gaskets as stated below:

«Ä» gasket of 0.27-0.33 mm;

«Ç» gasket of 0.70-0.80 mm

«ë» gasket of 1.10-1.30 mm.

Refit as shown in Fig.2-80 in the following sequence.

Locate the gasket A, then heat screen to the cylinder block,

next place the gasket B on the face mating the pump. Using tool
67.7834.9506 measure the distance «d» (minimum rod protru-
sion to be set through slow crankshaft rotation). When the size
«d» is within 0.8-1.3 mm, secure the fuel pump to the engine.
When the size «d» is below 0.8 mm, replace the gasket Ç with

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the gasket Ä. When the size «d» is over 1.3 mm, replace the gas-
ket Ç with the gasket ë. Recheck the size «d» and secure the
pump to the engine.

Make sure the gasket Ä is always fitted between the cylinder

block and heat screen.

Fig.2-80. Checking and adjusting the fuel pump pushrod projection:

Ä - gasket of 0.27-0.33 mm; Ç - gasket of 0.70-0.80 mm;
d - pushrod projection

45
 Carburettor The carburettor has two main fuel jet systems for the primary
and secondary barrels, a primary barrel idling system with air cor-

General description rection, a secondary barrel air correction system, part throttle
enrichment (economizer), full throttle enrichment (econostat),
The engine is fitted with the 21073-1107010 carburettor
diaphragm-type accelerator pump, semi-automatic choke control
(Fig.2-81) of emulsion, twin progressive throttle type. The carbu-
unit.
rettor features a balanced float barrel, a system of drawing
crankcase emission on the throttle body, a part throttle channel On the overrun an idling overrun control unit is actuated.
heater and secondary barrel locking. Refer to Table 2-2 for carburettor data.

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Fig.2-81. Carburettor 21073-1107010:

1 - throttle valve lever; 2 - secondary barrel lock lever pin; 3 - primary throttle valve opening adjustment screw; 4 - screw for choke valve cable end fitting; 5 - choke valve
control lever; 6 - choke valve lever; 7 - choke valve return spring; 8 - diaphragm rod, pull-down unit; 9 - fuel shutoff solenoid; 10 - fuel supply manifold; 11 - bracket for
choke outer cable end fitting; 12 - secondary barrel adjuster screw; 13 - secondary throttle valve lever; 14 - secondary throttle lever; 15 - primary throttle return spring

46
 Table 2-2

21073-1107010 CARBURETTOR
Parameters Primary barrel Secondary barrel

Barrel diameter, mm 32 32
Venturi diameter,mm 24 24

Main jet system:

• fuel jet marking* 107.5 117.5
• air jet marking 150 135

Emulsion tube, type ZD ZC

Idling and air correction systems, primary barrel:

• fuel jet marking 39 –
• conventional flow,** air jet 140 –

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Air correction system, secondary barrel:
• conventional flow, fuel jet – 70
• conventional flow, air jet – 140

Full throttle enrichment (econostat):

• conventional flow, fuel jet – 70

Part throttle enrichment (economizer):

• fuel jet marking 40 –
• spring compression (9.5 mm length), N 14.5±15%

Accelerator pump:
• atomizer marking 45 –
• delivery (10 full strokes), cc 14 –
• cam marking 4 –

Starting clearances***:
• choke valve (clearance Ç), mm 3.0 –
• throttle valve (clearance ë), mm 1.1 –

Diameters,mm:
• crankcase vent drilling 1.2 –
• vacuum advance unit orifice 1.2
• needle valve bore 1.8
• fuel return orifice to petrol tank 0.70

__________________________________________________________________________________
* Jet marking is flow-related. Flow rate is measured with a micrometer, calibrated against the reference jets.

** Conventional flow through the jet is determined against the reference jet under a special procedure; in operation no control is required.

***Starting clearances are as shown in Fig.2-86

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 cardiagn.com
Fig.2-82. Main metering system:
1 - main air jets and emulsion tubes; 2 - atomizers, primary and secondary barrels; 3 - balance orifice; 4 - fuel filter; 5 - return pipe with calibrated orifice to petrol tank; 6
- needle valve; 7 - float; 8 - secondary throttle valve; 9 - main fuel jets; 10 - primary throttle valve

Fig.2-83. Idling and air correction systems:

1 - fuel cut-off solenoid; 2 - idling fuel jet; 3 - idling air jet; 4 - fuel jet and tube, secondary air correction system; 5 - air jet, secondary air correction system; 6 - outlet ori-
fice, secondary air correction system; 7 - main fuel jets; 8 - primary air correction passage; 9 - idle mixture adjustment screw

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 cardiagn.com
Fig.2-84. Part throttle and full throttle enrichment systems:
1 - secondary throttle valve; 2 - main fuel jet, secondary barrel; 3 - fuel jet and tube, full throttle enrichment; 4 - main fuel jet, primary barrel; 5 - primary throttle valve; 6 -
vacuum port; 7 - part throttle diaphragm; 8 - ball valve; 9 - fuel jet, part throttle enrichment; 10 - fuel passage; 11 - choke; 12 - main air jets; 13 - injection tube, full throttle
enrichment

Main metering system. Fuel through gauze filter 4 (Fig. 2- Part throttle enrichment (economizer) operates when cer-
82) and needle valve 6 is fed to the float chamber. From the float tain vacuum level is maintained on throttle body 5 (Fig. 2-84).
chamber fuel flows through main fuel jets 9 to the emulsion wells Fuel is fed from the float chamber through ball valve 8. Valve 8
to be mixed with air, escaping from emulsion tubes 1 which are remains closed as long as the diaphragm is held retracted in the
built as one piece with the main air jets. Through atomizers 2 the intake pipe by means of the vacuum. With wide open throttle, the
air-fuel mixture flows to the primary and secondary venturi. vacuum decreases allowing diaphragm 7 spring to open the
valve. Petrol which flows through part throttle enrichment jet 9 is
Throttle valves 8 and 10 are connected so that the secondary
added to fuel passing through main fuel jet 4, providing a richer
barrel starts opening when the primary one is 2/3 open.
mixture.
Idling system runs on fuel from the emulsion well behind
Full throttle enrichment (econostat) operates at full engine
fuel jet 7 (Fig.2-83). Fuel is fed to fuel jet 2 which is fitted with fuel
load, at high, close-to-maximum speeds and wide open throttles.
cut-off solenoid 1. At the jet outlet the fuel is mixed with the air
Petrol from the float barrel through jet 3 (Fig.2-84) is delivered to
coming from the port and from a flared part of the venturi (to
the fuel pipe and further through injection tube 13 into the sec-
ensure the carburettor smooth operation at idling). Emulsion goes
ondary barrel resulting in a richer mixture.
under the throttle plate through the correcting orifice adjusted by
Accelerator pump is of diaphragm type, mechanically oper-
idle mixture adjustment screw 9.
ated by cam 6 (Fig.2-85) on the primary throttle spindle. With the
Air correction systems. Following the throttle opening but throttle valve closed, the spring retracts diaphragm 3 thus filling
prior to activation of the main metering system, the air-fuel mix- the pump with petrol through ball valve 8. As the throttle opens,
ture enters: the cam operates lever 5, whilst diaphragm 3 forces fuel through
- the primary barrel through idling fuel jet 2 and air correction ball valve 2 and atomizer 1 into the barrels enriching the air-fuel
system passage 8, located at the level of the closed throttle plate mixture.
edge; The pump capacity is invariable and is determined by the
- the secondary barrel through outlet orifice 6 being slightly cam profile only.
over the edge of the closed throttle plate. Fuel flows from jet 4 Choke control unit. Choke lever 4 (Fig.2-86) has three pro-
through the tube to be further mixed with air from air jet 5 flowing files. Its outer edge 4.3 operates throttle lever 11 through adjuster
through the idling air passage. screw 10 to start the engine when cold and to further rise the

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 engine speed. Inner profiles 4.1 and 4.2 operate choke lever 6
allowing choke opening to a certain amount at intermediate posi-
tions of lever 4. Rotation of choke lever 4 anticlockwise causes
the wider slot to release choke lever 6 stud; the choke is held in
a fully closed position by return spring 7. At the same time the
primary throttle is opened by means of lever 4 edge 4.3.
Choke 5 shaft is not centralized, therefore, after the engine is
started, the choke is opened by force of air flow, extending spring
7 to result in a leaner air-fuel mixture.
Vacuum from the throttle body operates diaphragm 1 and
opens the choke by means of rod 3. Adjuster screw 2 makes pos-
sible to control the degree of the choke opening.
The maximum choke opening rate at the engine start-up and
warm-up depends on choke lever 4 positions or choke lever slot
width.
Idling overrun control unit disables the idling system on
the overrun (during engine deceleration, downhill movement or
gear shifting) thus improving fuel economy and reducing CO
emission to atmosphere.

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Fig.2-85. Accelerator pump: On the overrun at over 2100 rpm and carburettor idle switch
1 - atomizer; 2 - fuel delivery ball valve; 3 - diaphragm; 4 - pushrod; 5 - operat- 7 shorted to «ground» (Fig.7-40) (throttle pedal released), fuel
ing lever; 6 - cam; 7 - primary throttle valve; 8 - non-return ball valve; 9 - sec- cutoff solenoid 4 is disactivated to shut off fuel supply. When the
ondary throttle valve
idle switch is not grounded, the solenoid will not be disabled.

Fig.2-86. Choke pull-down unit:

1 - diaphragm; 2 - adjusting screw; 3 - diaphragm rod; 4 - choke control lever; 4.1 - lever 4 bottom profile to restrict maximum choke opening; 4.2 - top profile to ensure
choke mechanical opening ; 4.3 - lever 4 edge to ensure primary throttle starting clearance; 5 - choke valve; 6 - choke lever; 7 - choke return spring; 8 - choke cable; 9
- adjuster screw stop; 10 - primary throttle opening adjuster screw; 11 - throttle lever; 12 - primary throttle; Ç - choke starting clearance; ë - throttle starting clearance

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 When the crankshaft speed goes down as low as 1900 rpm Refitting is a reversal of the removal procedure. Before refit-
on the overrun, the control unit re-triggers the fuel cutoff solenoid ting, examine the carburettor heat screen and intake pipe/carbu-
to feed fuel through the idle jet, and the engine gradually shifts to rettor mating surfaces. Tighten the carburettor nuts to the torques
idling. specified in Attachment 1.
Secondary barrel locking. The secondary throttle can open
only with the open choke when lever 5 edge (Fig.2-81) does not rest WARNING. Never refit or tighten the retaining nuts on the
against pin 2 of the secondary barrel lock lever. hot carburettor.
In this case during throttle opening the lock lever operates lever
After refitting, adjust the carburettor linkage and engine idle.
13 through lever 14 to open the secondary throttle.
The carburettor linkage should operate without seizures.
When the choke is closing, lever 5 outer edge operates lock
lever pin 2 to disengage lever 14 and lock lever. Now the sec-
Carburettor - dismantling
ondary throttle is locked out and cannot be opened.
Undo the retaining screws and remove the carburettor cover,
Carburettor - removal and refitting taking care not to damage the gasket, float and tubes of the full
throttle enrichment and secondary air correction systems.
Carburettor removal and refitting is done on the cold engine
Dismantle the carburettor cover.
only. Start with removing the air cleaner. Next disconnect oper-
ating rod 15 (Fig. 2-87) from the throttle lever, followed by oper- Using a tool, carefully push out spindle 1 (Fig.2-88) of floats
ating rod 3 and choke outer operating rod. Undo the retaining 3, providing you do not damage the float tabs, remove the floats.

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screw and remove the part throttle channel heater. Remove gasket 4, needle valve 2 seat, fuel supply pipe 11
Disconnect the idling overrun wiring from the shutoff solenoid and fuel filter 13.
and idle switch. Undo the carburettor retaining nuts, remove the Remove the housing of the idling fuel jet with fuel cutoff sole-
carburettor and plug the intake pipe. noid 10 and remove jet 9.

Fig.2-87. Carburettor linkage:

1 - longitudinal rod; 2 - rod securing clamp; 3 - choke cable; 4 - grommets; 5 - choke knob; 6 - shaft; 7 - throttle pedal; 8 - return spring lever; 9 - shaft support bracket;
10 - longitudinal rod end-piece; 11 - intermediate lever; 12 - bracket, intermediate lever; 13 - return valve bracket; 14 - return spring; 15 - transverse rod;
16 - carburettor

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 cardiagn.com
Fig.2-88. Carburettor cover components:
1 - float spindle; 2 - needle valve; 3 - float; 4 - gasket; 5 - diaphragm and rod, choke pull down unit; 6 - spring; 7 - adjusting screw; 8 - cover, choke pull down unit;
9 - idling fuel jet; 10 - fuel cut-off solenoid; 11 - fuel supply pipe; 12 - carburettor cover; 13 - fuel filter; 14 - choke valve; 15 - cap; 16 - spindle, choke valve and lever;
17 - choke control lever securing ball; 18 - choke control lever; 19 - lever spindle; 20 - bush for securing choke cable

Undo shaft 19, extract ball 17 with the spring, remove choke screw (CO adjustment screw) 29 and when applicable remove
lever 18, detach the choke lever spring. When applicable, undo screw 29.
choke retaining screws, withdraw plate 14 and spindle 16. Remove plastic plug 25 and undo idle mixture adjusting
Dismantle the diaphragm-type choke control unit, having screw 27.
removed cover 8 complete with adjusting screw 7. Lift out spring
Lift out part throttle enrichment cover 5, diaphragm 6 and
6 and diaphragm 5 with the rod.
spring.
Dismantle the carburettor housing (Fig.2-89) as described
Unscrew fuel jet 7 of the part throttle enrichment unit.
below.
Undo main air jets 12 with the emulsion tubes and main fuel
Remove accelerator pump cover 3 Òomplete with lever 2 and
jets 13.
diaphragm 1.
Using a screwdriver, remove accelerator pump atomizer 10,
Carburettor components -
followed by atomizers 11 of the primary and secondary barrels.
Grip the housing when removing atomizer 10. cleaning and inspection
Undo the nut of the primary throttle spindle, remove cam plate 4 Fuel filter. Wash the filter and blow dry with compressed air.
of the accelerator pump linkage, then the washer. Examine the filter. When the filter or the fuel supply manifold are
Undo the retaining screw, remove wire 30 from throttle stop damaged, renew them.

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 cardiagn.com
Fig.2-89. Carburettor housing components:
1 - accelerator pump diaphragm; 2 - operating lever, accelerator pump; 3 - cover; 4 - cam, accelerator pump linkage; 5 - cover, part throttle enrichment; 6 - diaphragm,
part throttle enrichment; 7 - fuel jet, part throttle enrichment; 8 - valve, part throttle enrichment; 9 - return valve, accelerator pump; 10 - atomizer and fuel feed valve, accel-
erator pump;11 - main metering atomizers; 12 - main air jets with emulsion tubes; 13 - main fuel jets; 14 - bracket to secure choke outer cable end; 15 - adjusting screw,
secondary barrel; 16 - stop, adjusting screw; 17 - cap, stop; 18 - primary throttle opening adjusting screw; 19 - primary throttle spindle and operating levers; 20 - secondary
lock lever; 21 - lock lever spring; 22 - secondary throttle shaft and lever; 23 - primary throttle valve; 24 - secondary throttle valve; 25 - idle mixture adjustment screw cap;
26 - return spring, secondary throttle lever; 27 - idle mixture adjustment screw; 28 - carburettor body; 29 - throttle stop screw (CO adjustment); 30 - idle switch wire; 31 -
part throttle channel heater

Float components. Wash the components in petrol and wipe the jets or other carburettor components with cotton wool,
examine them. The floats must have no damages. Check to see cloths or rags, since lint can foul up the fuel-emulsion ducting.
there are no damages on the needle valve sealing face and seat When excessively dirty, clear the jets with the help of a soft wood-
which can result in the valve leakage. The valve must easily oper- en needle soaked in acetone.
ate in its socket, the ball should not stick. The float weight should Carburettor housing. Clean the housing from dirt or oil.
not exceed 6.23 gram. Renew any damaged components. Wash the passages with acetone or petrol, blow dry with com-
Carburettor cover. Clean any dirt or oil from the cover, clean pressed air. Where applicable, use special tools for cleaning the
all passages and holes. Wash the cover in acetone or petrol, blow ports and emulsion tubes. Examine the sealing surfaces of the
dry with compressed air. Examine the cover sealing surfaces. housing; when found damaged or distorted, renew the housing
Renew the cover in there are any damages. with a new one.
Choke control unit. Wash in petrol and blow dry all choke Accelerator pump. Clean out the pump components, wash
control associated components. Inspect the parts and renew in petrol and blow dry with compressed air. Check to see the ball
when applicable. in the atomizers and moving parts (lever, diaphragm compo-
Jets and emulsion tubes. Clean out the jets and emulsion nents) operate smoothly. There must be no seizures or sticking.
pipes from dirt, gummy substances, wash in acetone or petrol, The diaphragm should be intact and undamaged. Examine all
then blow dry with compressed air. sealing surfaces and gaskets. Always renew any damaged com-
Do not use any metal tool or wire for cleaning the jets; never ponents.

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 Fig. 2-91. Throttle stop screw:
1 - throttle stop screw; 2 - idle mixture adjustment screw; 3 - sealing ring; 4 -
adjusting screw cap

Check the jet marking and consult Table 2-2 to prevent the

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jet confusion when refitting.
Before refitting pivot pit 19 (Fig.2-88), apply sealant ìÉ-9 on
the pivot end and over 1-1.5 end turns of thread.
To reassemble the accelerator pump, first hand start the
cover retaining screws, press the lever full way to stop, tighten
the screws and release the lever.

Carburettor - adjustment and checks

Setting fuel level in float chamber. The adequate fuel level
for proper carburettor operation is ensured by correct fitting of
good cut-off valve components.
Fig.2-90. Setting the fuel level in float barrel: Correct fitting of float 1 (Fig.2-90) is checked with gauge 4.
1 - float; 2 - carburettor cover; 3 - gasket; 4 - gauge to check the float position; To do it, locate it normal to cover 2, which should be held hori-
5 - needle valve
zontally with the floats up. The clearance between the gauge
Part throttle enrichment unit (economizer). The (over its contour) and floats must be 1 mm as a maximum.
diaphragm must be integral and have no damages. Renew the When necessary, adjust by means of bending the float tab or
diaphragm complete with the pushrod when the pushrod length levers. The locating tab face must be normal to needle valve 5
(the head included) is less than 6.0 mm. pivot and have no evident dents or cuts.
Choke control unit adjustment. When turning lever 4 (Fig.
Carburettor - reassembly 2-86) of choke 5 control unit full way anticlockwise, choke must
be completely closed by spring 7. If not, remedy the situation.
Reassembly of the carburettor is a reverse of the dismantling
With the choke fully closed, press choke control rod 3 to its
procedure. Special attention should be drawn to the following.
stop. This results in choke 5 opening to 3.0 mm (starting clear-
The float must freely turn on its pivot pin, there should be no ance B). Adjust the clearance using screw 2.
conflict with the barrel walls.
Primary throttle 12 with the choke fully closed, should be
The needle valve must freely operate in its seating, without open to 1.1 mm (starting clearance ë). Using screw 10, adjust
warping or seizure; the tightening torque for the needle valve the clearance as necessary.
seat is 14.7 N•m (1.5 kgf•m). Carburettor linkage adjustment. With fully depressed throt-
The tightening torque for the solenoid cutoff valve is 3.68 tle pedal 7 (Fig.2-87) the primary throttle must be wide open and
N•m (0.4 kgf•m). rod 15 must have no further travel. With pedal 7 released the

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throttle must be fully closed. If not, adjust the pedal and throttle
by means of end piece 10 at front rod 1 end.
Secure the end of throttle linkage cable 3 so that with knob 5
pulled, the choke is fully closed, while with knob 5 pushed in - fully
open.
Engine idle adjustment. This is to be done via idle mixture
adjustment screw 2 (Fig.2-91) and throttle stop screw 1. Cap 4 is
provided for adjustment screw 2. Remove the cap to access the
screw.
Idle adjustment is done on the warm engine (coolant to be at
85-90°ë), after the valve gaps and ignition timing are correctly
adjusted, the choke should be wide open.
Using throttle stop screw 1, set the crankshaft speed within
750-800 rpm.
Using idle mixture adjustment screw 2, set the content of car-
bon monoxide (CO) in exhaust emissions at maximum 1.5 % with
throttle stop screw 1 at the preset position as above (CO level is
for 20°ë and 101.3 ÍP‡ (760 mm Hg).
Reset the crankshaft speed to 750-800 rpm by means of

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throttle stop screw 1.
When applicable, restore CO level to the maximum 1.5 %.
On completion, sharply depress and release the throttle pedal
- check to see the engine speeds up without any gasps and does
not stall at lower rpm. Should the engine stops, use throttle stop
screw 1 to increase the engine speed to 750-800 rpm.
Refit new plastic cap 4 to idle mixture adjustment screw 2.
Checking the secondary barrel locking linkage. Turn the
choke lever anticlockwise to fully close the choke. Next, turn spin-
dle 19 lever (Fig.2-89) to wide open primary throttle 23; sec-
ondary throttle 24 must remain closed
Fig.2-92. Exhaust gas recirculation:
Turn the choke lever fully clockwise, turn throttle lever 19 to 1 - carburettor; 2 - thermo-vacuum switch of EGR valve; 3 - intake pipe;
wide open the throttle. If the secondary throttle fails to open, elim- 4 - exhaust manifold; 5 - EGR valve; 6 - recirculation tube
inate the fault. The fault can be caused by seized secondary lock
EGR valve does not open, check the proper operation of the EGR
lever 20 or disconnected lock lever spring 21.
valve and thermo-vacuum switch 2.

Exhaust gas recirculation system To check the EGR valve, disconnect the thermo-vacuum
switch. Using manual vacuum pump, build up vacuum in the EGR
The vehicle is fitted with the exhaust gas recirculation (EGR) valve diaphragm cavity. The EGR valve must be closed at 9.3
system which comprises thermo-vacuum switch 2 (Fig.2-92) and kP‡ (70-75 mm Hg). With vacuum level over 59.9 kPa (450-455
EGR valve 5 with the relevant port and recirculation tube 6 in mm Hg) the EGR valve must be fully open, which is checked
intake pipe 3. through a sharp vacuum removal - the EGR valve closes with a
When coolant is over 40-48°ë, the thermo-vacuum switch distinct click. In both cases no air leaks are allowed within 5 sec-
triggers to build-up vacuum in the EGR valve; the valve opens to onds.
reintroduce small amount of exhaust gas from exhaust manifold To check thermo-vacuum switch 2, disconnect the hose and
4 into the intake pipe and inside the engine. EGR valve 5. Using manual vacuum pump, build up vacuum of
Checking EGR system operation. Depress the throttle lever 13.3 kP‡ (100±5 mm Hg) to the thermo-vacuum switch. At
and smoothly raise the engine speed to 2500-3000 rpm. At coolant temperature maximum 30-38°ë no vacuum leaks are
coolant temperature of 30-38°ë EGR valve 5 must be closed, allowed (thermo-vacuum switch is closed). At coolant tempera-
while at coolant temperature of 40-48°ë it must be open, which ture below 40-48°ë there should be no vacuum (thermo-vacuum
can be evident through the EGR valve rod upward travel. If the switch is open).

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 cardiagn.com
Fig.2-93. Exhaust system:
1 - sealing gasket; 2 - downpipe; 3 - bracket to secure downpipe to transmission; 4 - connection clasp; 5 - suspension ring, main silencer; 6 - main silencer; 7 - front silencer

Exhaust system
Exhaust gases escape from the engine through the exhaust
manifold, front exhaust pipe (downpipe) 2 (Fig.2-93), centre
(front) silencer 7 and main (rear) silencer 6.
Gasket 1 is fitted between the exhaust manifold and down-
pipe. The silencer pipes are connected through their flared ends
by means of clasps 4 with taper rings.
Downpipe 2 is secured with nuts to the exhaust manifold
studs and in addition to bracket 3 mounted on the gearbox cover.
The lock plates are used under the manifold retaining nuts. The
nuts and gasket 1 are of disposal type. Rear silencer 6 is secured
to the underbody with the help of two suspension rings 5.
The silencers and associated pipes are made as a one-piece
unit, so in the event of their failure they are renewed as a unit.

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