It is of vital importance, before attempting to operate

your engine, to read the general 'SAFETY

INSTRUCTIONS AND WARNINGS' section on
pages 2-5 of this booklet and to strictly adhere to the
advice contained therein.
Also, please study the entire contents of this
instruction manual, so as to familiarize yourself
with the controls and other features of the engine.
Keep these instructions in a safe place so that you
may readily refer to them whenever necessary.
It is suggested that any instructions supplied with
the vehicle, radio control equipment, etc., are
accessible for checking at the same time.

CONTENTS
SAFETY INSTRUCTIONS AND
WARNINGS ABOUT YOUR O.S. ENGINE 2-5 STARTING THE ENGINE & RUNNING-IN 17-19

ENGINE CONSTRUCTION 6 FINAL ADJUSTMENT 20-22

NOTES WHEN APPLYING AN ELECTRIC CARBURETOR CLEANLINESS 22

STARTER 7
CARE AND MAINTENANCE 23-24
ABOUT THE ENGINE 8
CHECKING THE ENGINE 25
BEFORE STARTING 8-10
TROUBLE SHOOTING 26-29
BASIC ENGINE PARTS 10
ENGINE EXPLODED VIEW & PARTS LIST 30-33
CARBURETOR CONTROLS 11
CARBURETOR EXPLODED VIEW &
FACTS ABOUT GLOWPLUG 12 PARTS LIST 34-37

INSTALLATION 13-16
O.S. GENUINE PARTS & ACCESSORIES 38

THREE VIEW DRAWING 39-40

1
 SAFETY INSTRUCTIONS AND WARNINGS ABOUT YOUR O.S. ENGINE
Remember that your engine is not a "toy", but a highly efficient internal-
combustion machine whose power is capable of harming you, or others, if it is
misused.
As owner, you, alone, are responsible for the safe operation of your engine, so act
with discretion and care at all times.
If at some future date, your O.S. engine is acquired by another person, we would
respectfully request that these instructions are also passed on to its new owner.
The advice which follows applies basically to ALL MODEL ENGINES and is
grouped under two headings according to the degree of damage or danger
which might arise through misuse or neglect.

! WARNINGS ! NOTES
These cover events which These cover the many other
might involve serious (in possibilities, generally less obvious
extreme circumstances, even sources of danger, but which, under
fatal) injury. certain circumstances, may also
cause damage or injury.

! WARNINGS
• Model engine fuel is poi- • Never operate your engine in an en-
sonous. Do not allow it to closed space. Model engines, like
come into contact with the automobile engines, exhaust deadly
eyes or mouth. Always store carbon-monoxide. Run your engine
it in a clearly marked con- only in an open area.
tainer and out of the reach
of children.
• Model engines generate
• Model engine fuel is also considerable heat. Do not
highly flammable. Keep it touch any part of your
away from an open flame, engine until it has cooled.
excessive heat, sources of Contact with the muffler
sparks, or anything else (silencer), cylinder head
which might ignite it. Do not or exhaust header pipe, in
smoke or allow anyone else particular, may result in a
to smoke, near to it. serious burn.

3
 ! NOTES
• This engine is intended for model cars. • The wearing of safety glasses is also
Do not attempt to use it for any other strongly recommended.
purpose.

• Mount the engine in your model • Take care that the glowplug clip or
securely, following the manufacturers' battery leads do not come into contact
recommendations, using appropriate with rotating parts. Also check that the
screws and locknuts. linkage to the throttle arm is secure.

• Install an effective silencer (muffler). • For their safety, keep all onlookers
Frequent close exposure to a noisy (especially small children) well back
exhaust (especially in the case of the (at least 20 feet or 6 meters) when
more powerful highspeed engines) preparing your model for running.
may eventually impair your hearing
and such noise is also likely to cause
annoyance to others over a wide area.

! NOTES
Before starting the engine, always check • Warning! Immediately after a glowplug-
the tightness of all the screws and nuts ignition engine has been run and is still
especially those of joint and movable warm, conditions sometimes exist
parts such as throttle arm. Missing whereby it is just possible for the engine
retightening the loose screws and nuts
to abruptly restart if it is rotated over
often causes the parts breakage that is
capable of harming you. compression WITHOUT the glowplug
battery being reconnected.
• To stop the engine, fully retard the
throttle stick and trim lever on the
trans-mitter, or, in an emergency, cut
off the fuel supply by pinching the fuel
delivery line from the tank.

5
 Near TDC
ENGINE CONSTRUCTION

With this engine, the piston will

feel tight at the top of its stroke
Piston
(TDC) when the engine is cold.
Cylinder Liner
This is normal. The cylinder bore
has a slight taper. The piston
and cylinder are designed to
Crankshaft
achieve a perfect running
Slight taper
clearance when they reach
operating temperature.

When the engine is cold. When the engine is hot.

NOTES WHEN APPLYING

AN ELECTRIC STARTER

Do not over-prime. This could

cause a hydraulic lock and damage
the engine on application of the
electric starter.

If over-primed, remove glowplug,

close needle-valve and apply
starter to pump out surplus fuel.
Cover the head with a rag to
prevent any pumped out fuel from
getting into your eyes.

7
ABOUT THE ENGINE BEFORE STARTING
These engines are designed especially to power
Tools, accessories, etc.The following items are
the T-Maxx or Revo. Purposely designed LC3
necessary for operating the engine.
glow plug is supplied with the engine for
improved power, fuel economy and durability. Items necessary for starting
The carburetor offers easy handling as well as FUEL
high performance. Generally, it is suggested that the user selects a fuel
T-Maxx and Revo are trademarks of Traxxas Corp. that is commercially available for model two-stroke
engines and contains 10-30% nitromethane. As a
Standard accessories starting point, we recommend a fuel containing 20%
nitromethane, changing to a fuel containing more
nitro if necessary. When the brand of fuel is
Glow Plug LC3 changed, or the nitro content increased, it is
advisable to repeat the running-in procedure
Exhaust Seal Ring 1piece referred to in the RUNNING-IN paragraphs. Please
note that with high-nitro fuels,
Exhaust Manifold for T-Maxx although power may be increased
for competition purposes,
glowplug elements do not last as
long and engine life will be
Exhaust Manifold for Revo shortened.

Model engine fuel is poisonous. Do FUEL PUMP

not allow it to come into contact with For filling the fuel tank, a simple,
! the eyes or mouth. Always store it in a polyethylene "squeeze" bottle,
clearly marked container and out of with a suitable spout, is required.
the reach of children.
Model engine fuel is also highly SILICONE FUEL LINE
flammable. Keep it away from open Heatproof silicone tubing of
! flame, excessive heat, sources of approx. 5mm o.d. and 2mm i.d.
sparks, or anything else which might is required for the connection
ignite it. Do not smoke or allow anyone between the fuel tank and
else to smoke, near to it. engine.
FUEL FILTER
To be installed in the fuel line
between fuel tank and carburetor
to prevent foreign matter from
entering the carburetor.
GLOWPLUG IGNITER
Commercialy available handy
glowplug heater in which the
glowplug battery and battery
leads are integrated.
9
 TOOLS
HEX SCREWDRIVER BASIC ENGINE PARTS
Necessary for engine installation. Heatsink Head
1.5mm, 2mm, 2.5mm, 3mm

SCREWDRIVER Carburetor
Necessary for carburetor adjustments. Type 11K
No.1, No.2, etc

Exhaust

LONG SOCKET WRENCH WITH PLUG GRIP

Recommended for easy removal and
replacement of the angled and recessed
glowplug, the O.S.Long Socket Wrench
incorporates a special grip.
Rear Adaptor
Mounting Lugs
Crankcase

Crankshaft
MAX-21TM (T-Maxx)
10

CARBURETOR CONTROLS
Four adjustable controls are provided on
11K, 11K-R this carburetor.
The Needle-Valve:
Needle Valve For adjusting the mixture strength when the
throttle is fully open.

Mixture Control Valve The Mixture Control Valve:

For changing the mixture strength at mid
speed and acceleration. (Do not rotate the
Throttle Stop screw more chan one turn.)
Screw The Metering Needle:
For adjusting the mixture strength at part-
Thermo Insulator
throttle and idle speed, to obtain steady
idling and smooth acceleration to mid speed.
Metering Needle The Throttle Stop Screw:
For setting the minimum idle speed:

NOTE: Readjustment may be necessary,

occasionally to allow for changes in fuel
formula gear ratio or clutch engagement
point.

11
FACTS ABOUT GLOWPLUGS
Since the compatibility of glowplug and fuel may have However, plug life can be extended and engine
a marked effect on performance and reliability, it may performance maintained by careful use, i.e.:
be worthwhile to choose the R/C type plug found
Install a plug suitable for the engine.
most suitable after tests. Recommended O.S. plugs
are LC3. Carefully install plug finger-tight, before final Use fuel containing a moderate percentage of
tightening with the correct size plug wrench. nitromethane.
Do not run the engine too lean and do not leave the
The role of the glowplug battery connected while adjusting the needle.
With a glowplug engine, ignition is initiated by the When to replace the glowplug
application of a 1.5-volt power source. When the
Apart from when actually burned out, a plug may
battery is disconnected, the heat retained within the
need to be replaced because it no longer delivers its
combustion chamber remains sufficient to keep the
best performance, such as when:
plug filament glowing, thereby continuing to keep the
engine running. Ignition timing is 'automatic' : under Filament surface has roughened and turned white.
reduced load, allowing higher rpm, the plug becomes Filament coil has become distorted.
hotter and, appropriately, fires the fuel/air charge
earlier; conversely, at reduced rpm, the plug become Foreign matter has adhered to filament or plug
cooler and ignition is retarded. body has corroded.
Engine tends to cut out when idling.
Glowplug life
Particularly in the case of very high performance Starting qualities deteriorate.
engines, glowplugs must be regarded as expendable
items.

12

INSTALLATION

Install the engine on the engine mount with

ground wire.

Install the flywheel and

First, remove the original engine, from the clutch.
engine mount.

13
 T-Maxx Revo

Install the electric starter taken from the

original engine.
Install the manifold supplied with the engine.

14

T-Maxx Revo

Adjust the plastic ball end so that the throttle

linkage may be connected correctly.

Adjust the stopper end so that the throttle

linkage may be made correctly.

15
 Revo T-Maxx

Finally, connect the wire for glow plug heating

to the glow plug.

Finally, insert the wire for heating the glow

plug.

16

STARTING THE ENGINE & RUNNING-IN ('Breaking-in')

For long life and high performance, every Fill the tank completely with fuel.
engine needs to be 'run-in' or 'broken-in'. With
care, running-in of the MAX-21TM can be Temporarily remove the glowplug to check
carried out with the engine installed in the that it glows bright red when energized.
vehicle. Be sure to install the air-cleaner on the
carburetor and use a muffler-pressurized fuel Element glows when energized.
system. Pliers

The somewhat violent changes of vehicle

attitude that occur in off-road running,
combined with the fact that, in buggy type
cars, the fuel tank is often located some Replace the plug when the
distance from the carburetor, means that fuel element does not glow or is
'head' at the carburetor can vary and upset burnt out.
running.Therefore,it is recommended that a
muffler pressurized fuel feed system be used.
Glow Plug Igniter
Never run your vehicle without installing the
air cleaner. Dust and dirt that may otherwise
be drawn into the engine will rapidly shorten
its life.

17
 The carburetor on this engine has been set at Next, disconnect the glowplug battery and try
the starting setting when the engine leaves the running the car on the track. If the engine
factory. stalls, open the throttle fractionally, but try to
Switch on the transmitter, and check that all the keep the engine running as rich as possible: if
linkage moves correctly. it stops because of being excessively over-
rich, close the Needle-Valve 30˚ and try
Remember!
again.
It is vitally important to set
the throttle at the correct Run the car on the track until one tank of fuel has
position before attempting been consumed, then close the Needle-Valve
to start the engine. If the 30˚. Repeat this procedure again until five tanks
engine is allowed to run of fuel have been consumed, during which time
with the throttle too far the throttle may be opened for brief bursts of
open under "no load" increased power. If the engine stops at medium
conditions, it will rapidly speeds, close the Mixture Control Valve 30˚.
overheat and may be
seriously damaged. The position of the needle-valve
When the engine starts, first allow it to operate when starting the engine.
30˚
Needle
in short runs on its very rich starting settings,

30
with the glowplug battery still connected and

˚
Close the needle-valve approx.

30˚
with its driving wheels clear of the ground. The 30˚ after running the vehicle for
rich mixture will, under these conditions, every one full tanks of fuel.
provide adequate lubrication and cooling, Repeat this procedure around
indicated by profuse smoke from the exhaust. five times.

18

Note: Warning!
If the engine should need to be disassem- Do not touch rotating parts, engine and si-
bled (e.g. for cleaning or minor parts re- lencer when stopping the engine as they
placement), it is advisable to return the nee- become very hot, and contact with them
dle-valve to the original rich, starting set- may result in a serious burn.
ting and check whether further running-in
time is required before the car is raced
again. In the event of any major working
parts (e.g. piston/cylinder liner assembly)
being replaced or the fuel being changed,
especially to high nitro fuel, the complete
running-in should be repeated.
To stop the engine, close the throttle to idle
speed, then shut it off completely with the
trim lever on the transmitter.
To cut off the fuel supply,
pinch the fuel delivery tube
to the carburetor.

Fuel

19
FINAL ADJUSTMENT
Final adjustment should be carried out only after Run the vehicle (with throttle fully open) over
the running-in has been completed. the longest available straight course, in order
to observe the model's speed. Next return
Type 11K the car to the starting point, close the Needle-
Valve 30˚ and repeat the run, taking note of
the improvement in performance.
Needle Valve
Continue with further runs, gradually
reducing the Needle-Valve setting and
Metering Needle
aiming to achieve the highest straight-line
speed. Remember, however, that, if the
Throttle Stop Screw Needle-Valve is shut down too far, the
engine will overheat and, accompanied by
visibly diminished exhaust smoke, the model
Metering Needle Needle Valve will lose speed. At this point, throttle down
Open Close Open Close immediately, stop the vehicle and reopen the
Needle-Valve 30˚.

More fuel Less fuel More fuel Less fuel

20

With the engine running, close the throttle Warning!

and allow it to idle for about five seconds, Mixture adjustments (whether via the
then reopen the throttle fully. If, at this point, Metering Needle, or the Needle-Valve)
the engine puffs out an excessive amount of cannot be made accurately under 'no-load'
smoke and the vehicle does not accelerate conditions, which, in any case, are not
smoothly and rapidly, it is probable that the advised, since such operation carries the
idle mixture is too rich. In this case, turn the risk of seriously damaging the engine
Metering Needle clockwise 30˚. If, on the through over-revving and overheating.
other hand, the engine tends to speed up With the optimum mixture control position,
momentarily and then cut out abruptly when light smoke is visible during high speed
the throttle is opened, the idle mixture is too running,and the engine rpm increases
lean. Correct this by turning the Metering smoothly during acceleration. Remember
Needle counter-clockwise 30˚. that, if the engine is operated with the fuel/air
NOTE: mixture slightly too lean, it will overheat and
Metering Needle adjustment should be run unevenly. As with all engines, it is
made in steps of not more than 30˚, advisable to set both the needle-valve and
carefully checking the effect,on throttle metering needle slightly on the rich side of
response, of each small adjustment. the best rpm setting, as a safety measure.
If the engine runs too fast with the throttle
Carry out adjustments patiently, under actual closed, the throttle stop screw should be
running conditions, until the engine responds turned counter-clockwise to allow the throttle
quickly and positively to the throttle control. opening to be reduced.
21
 Finally, beyond the nominal break-in period, Carburetor Body 11K
a slight readjustment toward a leaner needle Ball Link
setting may be required to maintain Rotate the Metering Needle until
maximum performance. its slotted head is flush with the
ball link body. This is the
standard position.

CARBURETOR CLEANLINESS Slide Valve Metering Needle

The correct functioning of the carburetor
depends on its small fuel orifices remaining Carburetor Body 11K-R
Throttle Lever
clear.
Rotate the Metering Needle until
REALIGNMENT OF METERING NEEDLE AND its slotted head is flush with the
MIXTURE CONTROL VALVE Throttle Lever body. This is the
standard position.
In the course of making carburetor
adjustments, it is just possible that the Metering Needle
Slide Valve
Metering Needle and the Mixture Control
Valve may be inadvertently screwed in or out First rotate the Mixture Control
too far and thereby moved beyond its Valve until its slotted head is flush
effective adjustment range. with the carburetor body. Then
The basic positions can be found by rotating screw the valve in exactly 0.5 turn.
the Metering Needle until its slotted head is This is the standard position.
flush with the ball link body or throttle lever Mixture Control Valve
Carburetor Body
body.
22

CARE AND MAINTENANCE

1. The minute particles of foreign matter, that 3. At the end of each operating session, drain out
are present in any fuel may, by accumulating any fuel that may remain in the fuel tank.
and partially obstructing fuel flow, cause Afterwards,energize the glow-plug and try to
engine performance to become erratic and restart the engine, to burn off any fuel that may
unreliable. remain inside the engine. Repeat this
O.S. 'Super-Filters' (large and small) are procedure until the engine fails to fire. Do this
available, as optional extras, to deal with this while the engine is still warm.
problem.
One of these filters installed to the pickup 4. Then, inject some after-run oil into the
tube inside your refueling container, will engine, and rotate the engine with an
prevent the entry of foreign material into the electric starter for 4 to 5 seconds to
fuel tank. It is also recommended that a good distribute the oil to all the working parts.
in-line filter be installed between the tank and
Note:
carburetor.
Do not inject after-run oil into the
2. Do not forget to clean the filters regularly to carburetor as this may cause the O-rings
remove dirt and lint that accumulate on the inside the carburetor to deteriorate. These
filter screens. Also, clean the carburetor itself procedures will reduce the risks of starting
occasionally. difficulties or corrosion after a period of
storage.

23
5. Finally, when cleaning the exterior of the
Dirt and dust may lodge in marked places.
engine, use only methanol. Do not use
gasoline, kerosene or any solvent that might
damage the silicone fuel tubing.

Caution:
The rear crankshaft bearing of this engine
uses a special plastic retainer. If the front
housing needs to be heated to remove or
replace the bearing, do not allow the
bearing to exceed 120˚C (248˚F), otherwise
it may be damaged and rendered
unserviceable.

Installing Dust Caps (Optional extra)

When storing the engine, install the cap on
the exhaust port, carburetor, etc. to prevent
dust from entering the engine.

24

CHECKING THE ENGINE

If the engine suffers a loss of performance
after a long period of running it may be due to
the wearing of parts. It is suggested that the
worn parts be replaced when the following
symptoms are detected.
Engine sound changes and easily overheats.
Power has dropped considerably.
Idle is unstable and/or engine tends to stop
at idle.
In most cases, ball bearings, cylinder & piston
assembly, connecting rod and/or crankcase have
become worn out or abnormal. Check the
parts carefully and replace them if necessary.

25
TROUBLE SHOOTING
Symptom
Engine fails to fire.
Cause Corrective action
Fuel tank is empty. Fill the tank with fuel and repeat
Fuel not reaching the engine. Priming procedure.
Glowplug element is burnt out. Replace glowplug.
Glowplug battery discharged Recharge or replace the battery.
Clogged fuel filter Clean or replace fuel filter.
Air cleaner and silencer inside is dirty. Replace cleaner element and clean inside silencer.

Over priming Remove glowplug and pump out excess fuel.

Fuel tubing is disconnected. Connect fuel tubing securely.

Fuel tubing is kinked, split or has a hole. Check the tubing carefully and replace if necessary.

Incorrect servo linkage Connect correctly after setting servo at neutral.

Mare sure it rotates counter clockwise seen

Reverse rotating direction of starter box.
from crankshaft side.

26

Symptom
Engine fires intermittently but does not run.
Cause Corrective action

Insufficient fuel in the tank. Fill the tank with fuel.

Deteriorated glowplug Replace glowplug.

Clogged fuel filter Clean or replace fuel filter.

Air cleaner and silencer inside is dirty. Replace cleaner element and clean inside silencer.

Engine overheated Wait until engine is cool.

Incorrect clutch release Adjust the tension of clutch spring.

Do not disconnect plug battery and wait until

Starting battery disconnected too soon.
r.p.m. becomes stable.
Install "O" rings to the tank screws to
Vibration causing air bubbles in fuel.
prevent bubbles.

27
 Symptom
Unstable idle
Cause Corrective action
Unsuitable glowplug Use suggested glowplug in the instructions.
Unsuitable fuel Do not use extremely high nitro or low oil content fuel.
Extremely light flywheel Add heavier flywheel.
Silencer is disconnected or has play Install silencer securely.
Symptom
Not reaching expected peak r.p.m.
Cause Corrective action
Set the needle only after warming up.
Insufficient warming up or running-in.
Complete running-in.
Silencer or manifold is not securely connected Replace seal ring.
or disconnected. Check the connections and secure them.
Fuel tubing from tank is split or broken. Replace the tubing.

28

Symptom
Poor response
Cause Corrective action
Deteriorated glowplug Replace glowplug.
Readjust low r.p.m. range with metering
Incorrect carburetor settings
needle and mixture control valve.
Incorrect setting of transmitter Exponential function. Check the transmitter setting.

Incorrect linkage Make sure the throttle servo linkage does not
bind and is connected correctly.
Symptom
Poor r.p.m. drop
Cause Corrective action
Close metering needle to adequate position
Throttle position open too far. to lower idle r.p.m.
Carburetor not fully seated Install carburetor securely.
Metering needle closed too far. Open the metering meedle a little.

29
 21TM (T-Maxx) ENGINE EXPLODED VIEW
21TM (T-Maxx) ENGINE PARTS LIST

No. Code No. Description

C.M3x16 1
1 79871160 Cylinder Head Retaining Screw (10pcs.)
2 21914200 Heatsink Head
3 21921400 Head Gasket (1pc.)
4 21913300 Cylinder & Piston Assembly
2
5 23906000 Piston Pin
6 21817000 Piston Pin Retainer (2pcs.)
7 21915000 Connecting Rod
8 21982000 Carburetor Complete (Type 11K) 3
9 25381701 Carburetor Retainer
10 23731000 Crankshaft Ball Bearing (Front)
11 21921000 Crankcase M.+M2.6x7

12 21931000 Crankshaft Ball Bearing (Rear) 4

30
13 21912000 Crankshaft 6

31
14 21922000 Starting Shaft
15 21921800 Cover Gasket 5
17
16 21911800 Rear Adaptor
7
17 79860070 Rear Adaptor Retaining Screw (10pcs.) 16
8 15
71653000 Glow Plug LC3 14
21427200 Exhaust Seal Ring (2pcs.)
72103800 Exhaust Manifold M1020
Manifold Spring (2pcs.) 13
72106172
9
The specifications are subject to alteration for improvement without notice.
12

11

10

＊Type of screw C…Cap Screw M…Oval Fillister-Head Screw

F…Flat Head Screw N…Round Head Screw S…Set Screw
 21TM (Revo) ENGINE PARTS LIST 21TM (Revo) ENGINE EXPLODED VIEW

No. Code No. Description

C.M3x16 1
1 79871160 Cylinder Head Retaining Screw (10pcs.)
2 21914200 Heatsink Head
3 21921400 Head Gasket (1pc.)
4 21913300 Cylinder & Piston Assembly
5 23906000 Piston Pin 2

6 21817000 Piston Pin Retainer (2pcs.)

7 21915000 Connecting Rod
8 21982010 Carburetor Complete (Type 11K-R) 3
9 25381701 Carburetor Retainer
10 23731000 Crankshaft Ball Bearing (Front)
11 21921000 Crankcase M.+M2.6x7
12 21931000 Crankshaft Ball Bearing (Rear) 4

32
13 21912000 Crankshaft

33
6
14 21922000 Starting Shaft
15 21921800 Cover Gasket
5
16 21911800 Rear Adaptor 17
17 Rear Adaptor Retaining Screw (10pcs.) 7
79860070 16
Glow Plug LC3 8 15
71653000
14
21427200 Exhaust Seal Ring (2pcs.)
72103810 Exhaust Manifold M1021
72106172 Manifold Spring (2pcs.) 13

The specifications are subject to alteration for improvement without notice. 9

12

11

10

＊Type of screw C…Cap Screw M…Oval Fillister-Head Screw

F…Flat Head Screw N…Round Head Screw S…Set Screw
11K CARBURETOR EXPLODED VIEW

2-1

2-2

3
3-1

1-1 4
1-2 5 6

6-1
1

9 7
S.M3x3
10
Type of screw
8
C...Cap Screw M...Oval Fillister-Head Screw
F...Flat Head Screw N...Round Head Screw S...Set Screw

34

11K CARBURETOR PARTS LIST

No. Code No. Description

1 21982700 Mixture Control Valve Assembly
1-1 27881820 "O" Ring (L) (2pcs.)
1-2 22781800 "O" Ring (S) (2pcs.)
2 21285901 Needle Valve Assembly
2-1 27881820 "O" Ring (2pcs.)
2-2 21881950 No.14 Universal Nipple Assembly
3 21982620 Throttle Stop Screw
3-1 22781800 "O" Ring (S) (2pcs.)
4 21982100 Carburetor Body (w/Thermo Insulator)
5 21982200 Slide Valve
6 21982540 Metering Needle Assembly
6-1 22781800 "O" Ring (S) (2pcs.)
7 21982520 Dust Cover
8 23818430 Ball Link No.5
9 21982900 Thermo Insulator
10 22615000 Carburetor Rubber Gasket
The specifications are subject to alteration for improvement without notice.

35
11K-R CARBURETOR EXPLODED VIEW

2-1

2-2

3
3-1

1-1 4
1-2 5 6

6-1
1

9 7
S.M3x3
10
Type of screw
C...Cap Screw M...Oval Fillister-Head Screw 8
F...Flat Head Screw N...Round Head Screw S...Set Screw

36

11K-R CARBURETOR PARTS LIST

No. Code No. Description

1 21982700 Mixture Control Valve Assembly
1-1 27881820 "O" Ring (L) (2pcs.)
1-2 22781800 "O" Ring (S) (2pcs.)
2 21285901 Needle Valve Assembly
2-1 27881820 "O" Ring (2pcs.)
2-2 21881950 No.14 Universal Nipple Assembly
3 21982620 Throttle Stop Screw
3-1 22781800 "O" Ring (S) (2pcs.)
4 21982100 Carburetor Body (w/Thermo Insulator)
5 21982200 Slide Valve
6 21982540 Metering Needle Assembly
6-1 22781800 "O" Ring (S) (2pcs.)
7 21982520 Dust Cover
8 23818440 Throttle Lever
9 21982900 Thermo Insulator
10 22615000 Carburetor Rubber Gasket
The specifications are subject to alteration for improvement without notice.

37
 O.S. GENUINE PARTS & ACCESSORIES
RACING ENGINE PARTS
O.S. Glow Plug Exhaust Seal Ring Manifold Spring (2pcs.)
(2pcs.) (72106172)
(21427200)
LC3
(71653000)

Dust Cap Set Long Socket Wrench

3 (73300305)
With Plug Grip
For Carburetor Nipple (71521000)

7 (73300712)
For Silencer

12 (73301212)
For Carburetor

The specifications are subject to alteration for improvement without notice.

38

21TM (T-Maxx) THREE VIEW DRAWING

SPECIFICATIONS

■ Displacement 3.41cc (0.208 cu.in.)

■ Bore
31.4

17.0mm (0.669 in.)

■ Stroke 15.0mm (0.590 in.)
■ Practical R.P.M. 3,000-35,000 r.p.m.
■ Power output 1.8 ps / 1.83 hp / 29,000 r.p.m.
4- 3.3
■ Weight 243g (8.57 oz.) 11
85.3

JAPAN
M7x1
6

JAPAN
16

25.4 26.3 34.8 18.8 6

39 Dimensions (mm)

39
21TM (Revo) THREE VIEW DRAWING
SPECIFICATIONS

■ Displacement 3.41cc (0.208 cu.in.)

■ Bore

31.4
17.0mm (0.669 in.)
■ Stroke 15.0mm (0.590 in.)
■ Practical R.P.M. 3,000-35,000 r.p.m.
■ Power output 1.8 ps / 1.83 hp / 29,000 r.p.m.
4- 3.3
■ Weight 243g (8.57 oz.) 11

85.3

JAPAN
M7x1

6
JAPAN
16

25.4 26.3 34.8 18.8 6

39 Dimensions (mm)

40

6-15 3-Chome Imagawa Higashisumiyoshi-ku

Osaka 546-0003, Japan TEL. (06) 6702-0225
URL : http://www.os-engines.co.jp FAX. (06) 6704-2722

C Copyright 2007 by O.S.Engines Mfg. Co., Ltd. All rights reserved. Printed in Japan. 60091960 061104