(SJ

SACHS

(
Repair Manual No. 4010.8 E/2
SACHS-Wankel Engine
KM 3 7 (discontinued)
KM48

Edition September 1972

FICHTEL & SACHS AG · D-8720 SCHWEINFURT

 CONTENTS

Page
Introduction 2
Construction and function of the SACHS-Wankel engine 3
Installation dimensions ·for SACHS-Wankel engine KM 37 Folding Sheet
Installation dimensions for SACHS-Wakel engine KM 48 Folding Sheet
Technical data Folding Sheet
Repair tools and mounting jig 7
Dismantling the engine . . . 9
Working on individual parts
Exchange of seals without dismantling the engine 13
) Inspecting the end covers, rotor and rotor housing for wear .
Replacing the needle bearing (KM 37), the collar bush (KM 48), the spur
15

pinion and the oil seals . . . . . . . . . . . . 21

Eccentric shaft . . . . . . . . . . . . . . . . 23
Disassembling, decarbonizing and assembling the rotor 24
Decarbonizing the rotor housing 26
Muffler . . . . 26
Top speed limiting device 27
Recoil starter 28
Flywheel magneto and magneto-generator 31
Carburettor . . 32
Fuel pump 35
Assembling the engine 36
Timing the ignition 39
Intermediate flange and flange shaft 42
Single and two-stage gearbox . . 43
Precision governor KM 48 1st version up to engine No. 6440 768 48
Precision governor KM 48 2nd version from engine No. 6440 769 on 51
Centrifugal clutch (with gearbox) 56
Centrifugal clutch (without gearbox) 58
Lever-operated clutch K 160 . . 60
Devi.ce for heating the intake air 63
) BOSCH starter-generator 64
Instructions and wiring diagram for BOSCH starter-generator 65
Test-running the engine and running-in period 66
Installation or mounting the engine 68
Effects of location on engine performance 69
Laying-up the engine . . . . . . . . . 69
Lubricating and servicing chart . . . . 70
Appropriate lubricating oils for SACHS-Wankel engines 72
Tightening torques for bolts and nuts 73
Engine troubles . . . . . . . . . . . . . . . 74
Appendix
Housing cover for evacuation of air; execution for Messrs. ROTOMARIN
and SKICRAFT . . . . . . . . . . . . . . . . . . . . . 75
INTRODUCTION CONSTRUCTION AND FUNCTION OF THE SACHS-WANKEL ENGINE

Construction

This manual is designed to give dealers and their staff all guid- Basic elements of the engine are the rotor hous ing and the triangular rotor. All
sealing elements are contained in the rotor which is supported by the eccentric shaft.
ance and information necessary to enable them to provide and The chambers formed between the rotor and the rotor housing are closed by two
end covers. In the end covers as well as in the housing, ports for the gas flow
efficient repair and maintenance service, but it is in no way in- are ca•st. Each working chamber is kept tight on all sides by the seals. They form a
tended as a substitute for the practical and theoretical training continuo·us sealing line comparable to the one produced by a piston ring . The apex
seals warrant, inspite of the eccentric rotation of the rotor, positive tightness at
available to personnel at ou r Service Training School. all times.
It will be found useful as a ready reference in day-to-day work- Counterweights are provided eccentrically in the magneto and in the flywheel on
the power take-off side, compensating any uneven centrifugal forces created by the
shop practice. rotor. This results in the advantage of building a mechanically completely balanced
engine.
Our illustrated Spare Parts List, which shows the various compo-
nents in detail, will also be found helpful when used in conjunc- Function
tion with this booklet. While the rotor rides on the mainshaft and turns in an eccentrically manner, three
Naturally, good maintenance and repair work and efficient serv- chamber volumes are constantly decreasing and increasing.
Because of the 3 :1 speed ratio from the shaft to the rotor, each revolution of the
icing call for good equipment, a well-equipped workshop and rotor delivers 3 power phases (each rotor face accomplishes a full four-stroke cycle).
skilled personnel. Per shaft revolution, one power impul.s e is produced which corresponds to a rotary
angle of the rotor of 120 °.
Dealers are requested to make this manual and all SACHS Service The pressure of the expanding gases acts on the lobes of the rotor and produces
Bulletins, which contain technical modifications, available to every rotary motion that is transmitted over the eccentric bearings, which exert leverage,
individual responsible for actual servicing. The proper place to the output shaft.
for this kind of technical information is in the work- in the four-stroke Wankel engine, all three working chambers are in cont•inuous
action, a•s described and illustrated by the following sketches (rotor revolves
shop and not in the filing cabin;et. clockwise):
We hope that this manual will be of real practical assistance to
all our dealers, agents and associates.

FICHTEL & SACHS AG

D-8720 SCHWEINFURT
Service Department
Fig . 1
) At the firing point, a few degrees
before TDC 1, the chamber vo -
lume between A and C is at its
smallest. Intake is going on
through the ports between A
and B.
Camber between B and C has
just started its exhaust phase.
1
) in comparison with the reci -
procating engine :
TDC minimum chambe r
volume
BDC maximum chamber
volume Fig. 1

2 3
 Fig. 2 Fig. 5
The rotor face between B and C The fuel-air mixture is produced
is just completing the exhaust by a conventional carburettor.
phase and starts a new intake Before entering the chamber,
phase. That rotor face is at its the fuel-a·ir mixture is drawn, as
top dead center, while both the depicted by the sketches, either
exhaust and the intake port are trough the ports in the eccen-
open. tric, or through the ports in the
rotor, for cooling and lubrica-
ting the moving parts.
The intake port shown in the
first sketch, in the chamber be-
tween A and B, is in permanent
communication with the carbu-
rettor.
Fig. 5 ill·ustrates the direction of
) flow.
Fi g. 2 Fig . 5

Fig . 3
The chamber between B and C
is about to complete the intake
phase, shortly before its bottom
dead center.
Ignition has taken place be-
tween A and C.
Scavenging contin·ues between
A and C.

Fig . 3

Fig . 4
The chamber between B and C
goes ahead with compression .
)
Chamber between A and B has
just started exhaust phase.
Intake is shown between C and
A.

Fig. 4

4 5
 r \ _,, , ----.--1 I - r 1- ->w" -------1 9
"-.J z
(/)
-1
)>
r-
r-
)>
.::1 :::!
0
z
c
3:
m
z
(/)

0
zen
"TT
0
;:11.::1

a J
3 en
)>
0
:I:
~~~
• + 1mm ~ .J
(/)

::
)>
I

z
~
m
r-
m
z
0
z
m
~
3:
w
......
/
4-1 y
- - t o '"

A Wet air cleaner E Built-in centrifugal clutch J Distance to cen_ter line of rotor housing
8 Air filter with Micro-Star element F Cen t rifuga l cl utch with drum K Single stage gearbox
c Fuel pump and top speed limiting device G Built-in, lever operated clutch L Two-stage gearbox
D Vertical mounting of the engine H Center li ne of ro tor housing

In the interests of further development, all mod ification rights are reserved .
INSTALLATION DIMENSIONS FOR SACHS-WANKEL ENGINE KM 48
12874 ..
~--------- ca. 32T
- - - - - - - - - - - - - - - - - - - - -ca. 420 16,535"

_ _ J_ _ _ _ _
I
(

~
"'~ ~-
bl
""" "'8
"'0u

3,228 " • j'

---- - - - - - - '- - - -- - - 263 10.354 .. '--- - -oa. 200 7.874" f &S t.D15 ' ]

A = Pedestal plate
In the interests of further development, o il modificat ion righ ts are reserved.
 INSTALLATION DIMENSIONS FOR SACHS-WANKEL ENGINE KM 48

-p-
D
l ~

r
I
I
I
_J __

- -t---- - - - - - - - ea. 270110{530"'- - - - -----1 F &5401S:4

A = Suppressed ignition cable C = Fuel pump E = Starter·generat r G = Precision governor

B = Top speed limiting device D = Housmg cover for air evacuation F = Engine for hori ontal mounting
In the interests of further development, all modification rights are reserved.
 INSTALLATION DIMENSIONS FOR SACHS-WANKEL ENGINE KM 48
* - - - - - - - 198 77 ..
-~ ~---- ca. 116 = 6·_· -~
4 =6><-

/'-1~-----
/ tl ""
I I

~~
\

\
172 6 771"
I II I
I I

'--- -- - - -- ca. 214 8,.,1.2"-"S'---

"- ------.J

F&St.Ol5:5
l..-- -- - - - --ca.222'-"8'-"740,__ _ _ _ _ _ ___,
In the interests of further development, all modifi catio n rig hts are reserved.
 INSTALLATION DIMEN SIONS FOR SACHS-WANKEL ENGINE KM 48
9, 54"
- - - ca. 232.5 - = F - --+1
- ca. 198,5 '18 15"

! "''
~-
~
) I
I
y

A ** -
- 156,5 -----"'""-'---o-1
179-----"-'7.0""4'--7'_' _ ______,~

II II II II
FSSL.01S:6
<(ccUO

In the interests of further development, a l l modification i g hts are reserved .

CHNICAL DATA
Description : SACHS KM 37 SACHS KM 48
CHS-Wankel engine KM 37 SACHS-Wankel engine KM 48 Type: SACHS-Wankel engine
kW (P S) Coo lin g: Air cooling by fan
6,6
PS p D ire ction of rotation Counter-clockwise , seen on PTO-side of the eccentric shaft
5,9 of the eng ine:

5,1 Chamber volume: 108 cc (6.590 cu. in .) I 160 cc (9.763 cu . in.)

Compression: 8.5: 1
I 8 :1
4,4

3,7
Output : 3.45 HP (DIN l at 3000 1/ min.
5.5 HP (DI N at 4900 1/ min.
I 5.0 HP [DIN l at 3000 1/ min.
8.0 HP DIN at 4800 1/ min.
less 2°/o if an extra silent muffler is fitted
2,9 4 I
less 5'/o if a precision governor is fitted

2.2 Eccentric shaft 2 a nt i-friction bearings

bea rings:
1,5 Engine lu brica ti on: Mixture lubrica ti on 1 :50
2000 3000 4000 5000 (see page 72 for appropriate oi ls)
0,7
----•U/min Ig nition system : BOS CH magneto

<pm 100 0 2000 3000 4000 5000 6000 I

on request BOSCH magneto-genera tor
1/mi n Firing point: 10° . 12° before top dead center
M Nm (kpm)
Contact breaker
15,7 1,6
gap:
0.4 ± 0.05 mm (0.016 ± 0.002 in.)

13,8 1,4 Pol e shoe gap : I 7 . . . 10 mm (0.275 . . . 0.394 in.)

11,8 1,2
~M Spark plug : BOSCH W 150 M 11 S (for partial load)
BOSCH W 190M 11 S (for fu ll load)
10,0 1,0 electrode gap 0.5 mm

7,8 0,8 Carbure ttor: BING butterft y valve carburettor (/; 14 mm, w ith le ve r or cab le control,
on request with fuel pump (su cti o n capacity ma x. 30 em = 11.8 in.)
2000 3000 4000 5000 5,9 0,6
U/ m in Carburettor setting: Main jet Idle jet Idle air adjusting Mi xing tube
85 60 screw (/; 2.7
3,9 0,4 11h turn open

2,0 0,2 Air filter: Air filter with Micro-Star element or we t air cleaner with in tak e silencer
/PS h
Starting method : Recoil starter, Starter pulley or Starter-generator 12 Volt 160 Wa tt
10 00 2000 3000 4000 5000 6000 (batte ry required 12 Volt 18 Ah)
1/ m in
g/kW h (g/PSh) Fu el tan k: 4 litres (0.88 Im p . gall ons)
816 600 Muffl e r: standard, on request extra si lent version

?00
680 Governor:
I
Top speed limiting device
on request precision governor
±
544 400 precis ion accuracy 2.5°/o
)
2000 3000 4000 5000
- - --+U/min
408 3 00 Si ng le stage
gearbox: i
= 1.5
I = r= 2000 1/ min)
1.8 n = 1670 1/ min )
i = 2. 0 n = 1500 1/min)
i
i
I
=
=
=
1. 5 r
= 3000 1/ min)
1.8 n =' 2500 1/ min)
2.0 n = 2250 1/ min)
1000 2000 3000 4000 5000 6000 i = 2.8 n =' 1070 1/ min ) i = 2.8 n = 1600 1/ min)
n (rpm) w ill be s up erseded by 1/ min 1/ min re ferred to engine speed n = 3000 1/ min referred to engine speed n = 4500 1/ min
F&St.015 : 2

ne versio n
lang e mou nted e ng ine w ithout gearbox To ascerta in the output according to the G er-
Two-stage gearbox :
i = 5.6 [n = 535 1/ m in)
i = 6.9 n = 440 1/ min)
i = 7.8 [n = 380 1/minl
i
i
;
=
=
=
5.6
6.9 n = 650
7.8 n = 575
r
= 805 1/ minl
1/ min
1/ min)
,unter- clockwise rotation man Standard DIN 6270 (bo = 981 mbar a nd
•d es tal mo unted engine wit h s ingle stage tl = 20° Centigrade). the above-mentioned i = 10.6 n = 280 1/ min i = 10. 6 n = 425 1/ minl
!a rbox clockw ise rotation output has to be multiplied by the correct ive referred to engine speed n = 3000 1/ m in refe rred to e ngin e speed n = 4500 1/ min
•destal mounted e ngine w ith two-stage factor 0.97.
~ arb ox cou nter-c lock wise rota ti on For continuous operation (e. g. for driving a Weight : Flan ge-mou nted engine wit hout fuel Standard engine 20 kg (44 lbs)
sta ted r.owe r output applies to a fully run- generating set with governor) the engine should tank 15.5 kg (34.2 lbs)
ngine (5 ... 10 runn ing hou rs) a nd to a be run at not more than 90°/o of the DIN 6270
mete r reading bo = 101 3 mbar at an air rating. Attachments : Flexible coupling, V-belt pulley, Bu ilt-in, lever-operated clutch K 160,
erature tl = 20° Cent igrades (68° F). Built-in centr if ugal clutch, Centrifugal clutch

e interests of further development, all modification rights are reserved .

 REPAIR TOOLS AND MOUNTING JIG

~6
4

8 9
2 3 5

)
10
11
12

13
l
I
15
14

22

)
17

19 16 18
Ft.S40U:GZ/2

7
 I Engine DISMANTLING THE ENGINE
~o

..=z Port Number Descri pt io n ..... <X> Remove all connections from the engine to the equipment {control cables, electric
M
:::.;:
'<t
:::.;:
connections etc.) as well as the air filter from the carburettor.
Remove the engine and clean it thoroughly before dismantling.
- "" ""
Fuel tank, muffler and carburet-
tor
Repair tools f,ig. 6
1 0276161101 Oil seal puller . . . . . . . . . . . . . X X
If there is one, unscrew the fuel
0276164100 Puller hook 3 mm (0.11 8 in .) (1 piece)}spare parts for tank {z) wi~h support.
1476012000 Thrust beari ng . 0276161 191 Remove both plugs {x), unscrew
2 2776009000 Mounting sleeve for e cce ntric shaft {magneto s tde ) with a hexagon Allen key the
up to engine No . 6440 768 . . . . . . . : . X X
muffler (a ), remove e xhaust gas-
2776009 001 Mounting sleeve for e ccentric shaft (magn eto stde) ket and, if there is one, the
for engine No. 6440 769 on . . . . . . . . . X
device for heating the intake air.
3 2776010000 Mounting sl e eve fo r eccen t ric sha ft {powe r tak e - Unscrew the carburettor (h) with
off side ) . . . . . . . . : . . X X
intake pipe {d), disconnect the
4 0276156000 Protective ca p, bore 10 mm (0.394 !n.) . X X
governor rod and remove it
5 0976088100 Protective cap, bore 14 mm {0.551 !n.) . X
together with gasket.
X
6 2776022000 Pro te ctive cap, bore 20 mm (0.787 m.) . X X
If necessary, unscrew the intake
7 2776025000 Ad justing s le e ve fo r precision governo r pipe.
X
8 0276150005 Puller fo r magneto flyw heel M 26 x 1.5 . . . X X Note:
9 0976103100 Puller for flywheel , clutch disc and clutch flange X X
10 0277086404 Hook w rench . . . . . . . X X
On engines with BOSCH starter-
11 2776018000 Riveting stock for eccentric sha ft X X
generator, proceed as explained
12 2776021 000 Rivet ing too l on page 64.
X X
13 0276170000 Torque wrench . . X X
14 0276175000 Revolution counter X X Recoil starter, fan housing and
15 2776017000 Decarbonizi ng tool
I~
X starter housing
16 1476013000 Puller assembly . . X
1476011 000 Fig. 7
Threaded sleeve }
1440027001 Screw, hexagon head spa re parts for 1476 013 000 Mount the engine, as illustrated,
1476012000 Thrust bearing . onto the jig {repair tool No . 19,
17 1447010000 Clamping ring, inne r d iameter 75 mm (2.283 tn. ) . X X 20, 21 and 22).
18 1476014021 Puller shell s fo r dr iv ing p inion, sh a ft d ta 25 mm Unscrew the pedestal plate {x),
(0.984 in .) X X if there is one.
Unscrew the recoil starter {a )
an-d the fan housing (p ), taking
Mounting jig care of the dowel sleeves.
Unscrew the starter drum from
19 0276081 000 Cl a mping base X X the magneto flywheel.
20 0276082000 Sw ivel unit X X On KM 48 engines, unscrew the
21 0276085005 Cl a mp screw . . X X fan wheel with cast starter drum.
22 2776007001 Mounting bracket X X Remove cover plate.

Magneto flywheel
Fig. 8
Set the hook wrench (k, repair
tool No. 10) on the magneto fly -
wheel and unscrew the collar
nut.
Remove the spring washer.
Place protective cap (repair tool
No. 4) on the th readed end of
the mainshaft and pull the mag -
neto flywheel with puller {n,
repair tool No . 8).

8
9
 Armature base plate End cover on power take-off
side
Fig. 9
Fig. 12
Screw off spark plug cap (k) and
remove rubber cap (x). Unscrew 18 nuts and remove the
Unscrew armat-ure base plate hexagon head screws, each with
(s) and lift it off with its cables. 2 washers.
Take care of heat-resisting pro- Lift off the end cover (p). Take
tective tube (n). care of seals, corner seals and
Al'<"ays fit armature base plate springs that rnay have remained
and the magneto flywheel toge- stuck (protect the end cover face
ther. from damages).
Remove rubber grommets (a and
b) and the key.

' ig. 9 ) Fig. 12

Flywheel Rotor and rotor housing

Fig. 10 Fig. 13
Place the hoo k wrench (n, re- Remove rotor (a ), take care of
pair tool No. 10) with its long sea.ls, corner seals and springs
stud between the flywheel face that may have remained stuck
and the housing cover and un- (protect the rotor from dam -
screw the nut. ages).
Remove the spring washer. Undo screws (g), loosen the
Set protective cap (repair tool !bracket of the•mo·unting jig, push
No. 6), screw puller (o, repair outwards, force out the dowel
tool No. 9) with 2 fillister head sleeves (s) upwards with a cylin-
screws (y) M 6 x 60 and pull the drical pin and remove the rotor
flywheel. ho·using (x) (protect the rotor
Remove the key. ho·using from damage).

Housing cover and fan cover Bearing cover

Fig . 11
Unscrew cover (k) or fuel pump
)) Fig. 14
Unscrew 3 hexagon socket head
with gasket. On KM 37 engines, screws, remove bearing cover
unscrew bracket (g) from fan (f) and sealing ril')g.
cover. Remove circlip (n) and shims, if
Unscrew nuts (y) and remove there are.
hexagon head screws, each with
2 washers.
Take off housing cover (a) and
fan cover (x). Take care of
dowel sleeves.
On KM 37 engines, unscrew the
connection pipe (z) from the
magneto side end cover.
1----
Fig . 11

10
11
 Eccentric shaft WORKING ON INDIVIDUAL PARTS
Fig. 15 Exchange of seals without dismantling the engine
Remove the magneto side end
cover from the mounting jig. To pull out defective seals, a special seal puller (repair tool No . 1) is ·used.
Take out eccentric shaft (e ) from
the end cover by tapping on a
wooden block and remove deep
groove ball bearing .
Pulling the seals
Fig. 16
Always observe and note the
seal's installation measurements
x, o or y before pulling seals, so
that the new seals can be pres-
sed in with the identical mea-
g . 15 surements.

horoughly clean all parts, check for wear (checking the end covers, the rotor and Note:
1e rotor housing see page 15) and replace as needed . .
· is advisable to replace all gaskets when overhaulmg an engme . The non-observance of the seal 's
installation mea,s urements can
Jse only Genuine SACHS spare parts. result in engine troubles, through F& s on: J
the closing of oil channels in the Fig. 16
crankcase or through seizure of
rotating parts.

Fig. 17
It is impossible to pull a seal
from outwards, when it 1s
blocked by a lip (a ).

Fig. 17

12 13
 Fig. 18 Inspecting the end covers, rotor and rotor housing for wear
Apply the seal puller assembly, 1. End covers
so that both ends of the seal The magneto side end cover and the power take-off side end cover can be
hooks (4) are seated behind the refinished 3 times and rep laced separately.
steel rim of the seal. Press the The end covers are available on a trade-in basis and are marked according to the
two arms (2) equally outwards number of refinishings with N I (= 1st refinishing ), N II or N Ill and are to be
by screwing the two screws (1) obtained through a F & S representative.
in observing that the crankshaft The end covers are acceptable for trade-in, if they are free from breakage, cracks
(5) and thrust bolt (3) are aligned. and do not have any damage caused by violence.
In foreign countries, where trade-in parts cannot be obtained for reasons of custom
clearance or dispatching procedures, it is possible to refi nish end covers when the
following is observed: .
al Refinishing is to be done on a rotating bed grinding machine.
b Roughness : Rt = 6.3 1.1 m (0.00248 in.) corresponds toT T T according to German
Standard DIN 3142, row 2.
c) Insert the end cover by its bore and adjust it in such a manner that the face
g . 18 run-out measured at the working area of the rotor on the end cover does not
exceed 0.01 mm (0.0003937 in.).
d) Permissible unevenness 0.02 mm (0.0007874 in. ).
The end covers can be refinished 3 times (0.3 mm = 0.0118 in . each ). The end covers
are to be marked according to each refinishing process, for example :
Fig. 19 N I = 1st refinishing
If the distance between the shaft N II = 2nd refinishing
and the steel rim of the seal N Ill = 3rd refinishing
does not allow the seal puller
to be inserted, remove one of
the arms and insert both hooks
(1) at an angle. Marking the end covers.
Fasten arm and pull seal. Fig. 21 and 22
Note: Powe r take-off side end cover
The steel r-im of the seal can rip
apart in the case of stuck or
oxydized seals. It is therefore
recommended to first loosen the
seal from its seat by tapping it F & 5 4010:150
lightly with a piece of pipe.
ig. 19 Fig. 21
Magneto side end cover
Installation:
Fig. 20
Be·f ore installing the seal, fill the
hollow space with high tem-
))
perature grease and lubricate
the sealing lip slightly. .
To prevent damage to sealmg
lip from sharp edges on the
shaft, use adapter sleeve. In case
of need, the sharp edges can be
covered with a piece of scotch When mounting a refinished
tape. end cover, check the length of
Set the seal onto the shaft and the dowel sleeves and when
tap it into place ~ith a prope.rly necessary shorten them Fig . 22
sized piece of p1pe, observmg
the installation measurements x, from to
y oro of Fig. 16. KM37 41.5 mm (1.634 in.) 40-0. 2 mm (1.575 - 0.0079 in .)
Do not press in seal in an an- KM48 54.5 mm (2.146 in.)
gular position . 53 - 0.2 mrn (2.086 -0.0079 in.)
ig . 20
15
4
 IStandard 11 st refinishing I2nd refinishing 13rd refinishing
_I

!B
End cover

lit (PTO side) No. 12711 003 200 12711 003 202 12711 003 203 12711 003 204

Height of hub "H" 01 01 01

137.5 -O.l mm 137.2 - - mm 136.9 - - mm 136.6 - mm
I l'lS4eU : IIol
<Ill- 0
1.477 - · 0039 0
in. 1.4649- -0039 0
in. 1.4524- -0039 in. 1.4406- 0-0039 in.

Distinctive marking INI IN II IN Ill

I
Fig . 23

Standard 1st refin ishing 2nd refini$hing 3rd refinishing

End cover
(magneto side) No. 12711016202 12711016212 12711016213 12711016214

01 01 01
Height of hub "H" 22.0 + 0·1 mm 121.7 + · mm 121.4 + · mm 121.1 + · mm
<Ill- O.B66 + 0·0039 0
in. O.B542 + · 0039 0
in. O.B424 + · 0039 in. O.B306 + 0·0039 in.

flSioOU : II,I / 2
Distinctive marking
I Shim 0.3 mm
1
I NI N II lN Ill
I
(0.011B in.) I 1 x 2744 034 000 l2 x 2744 034 000 3 x 2744 034 ()()()
Fig . 24

8 'J

Repair di~nsi;n~ for SACHS-Wankel engine KM 48

I Sta ndard T1st refinishing T2nd refinishi ng T3rd refinishing

End cover
(PTO side) No. 12711 01B 200 12711 01B201 12711 01B 202
j 12711 01B 203

!19 I
iI
I
li~ I'I S 4.0\t : I4J
Height of hub "H"
<Ill-

Collor bush No.

Height of
collar bush
1
130.0 -0. mm 129.7 -0. mm
1
129.4 - 0-1 mm 0-1 mm I
1.1B1 -0.0039 in. 1.1696-0.0039 in. 1.1577-0.0039 in. 1.1459-0.0039 in.
12747 006 200
141
I
(1 6142 . ) 140 mm (1.574B in.)
2747 006 200
-

mm · '"· The bush must be shortened by 1 mm (0.03937 in.).

•<
Fig. 25
Distinctive marking T INI IN II I N Ill

End cover
(magneto side) No. 12711 016 300 2711 016 306
Bore "D" = (/) 4B mm 2711 016 307 2711 016 30B
(1.B90 in.)
End cover
(magneto side) No.

fl
for precision governor! 2711 016 301 2711 016 309 2711 016 310 2711 016 311
Bore "D" = (/) 4B mm
(1.B90 in.)

=~-j--'i==
End cover

[] ior t (magneto side) No. 12711 016 200

Bore "D" = (/) 46 mm
(l.B11 in.)
2711 016 206 2711 016 207 2711 016 20B

1 i ~ D -----.l i
F&. s 4111:141 / 2
End cover
(magneto side) No.
for pecision governor I 2711 016 201 2711 016 209 2711 016 210 2711 016 211
Bore "D" = (/) 46 mm
(l.B11 in .)
Height of hub "H" 22.0 + 0·1 mm 121.7 + 0·1 mm 21.4 + O.l---::--121.1 + 0·1 mm
<Ill-- O.B66 + 0·0039 in. O.B542 + 0·0039 in .1O.B424 + 0·0039 in. O.B306 + 0·0039 in.
Shim 0.3 mm [0.11B in.) / 11 x2744 034 000 12 X 2744 034 000 13 X 2744 034 000
Distinctive mark ing INI INII INII I
'-J Fig. 26
Note: a) Apex seals
After eeJch refinishing of end covers, and in order to prevent the eccentric shaft Fig. 28 and 29
from axia l movements, a shim (F & S part No. 2744 034 000) of 0.3 mm thickness
The apex seals are to be measured at the positions (a, b and c) w ith a mic rometer.
(0.0118 in.) each must be placed between the magneto side end cover and the spur
pinion (o , Fig. 34).
1st refinishing - 1 shim
2nd refinishing - 2 shims Original measurement
3rd refinishing - 3 shims for KM 37 :
........
The collar bush in the power take-off side end cover in the KM 48 engine with
41 mm {1.6142 in .) length must be shortend to a total length of 40 mm (1.574B in.) at
the 1st refinishing. This shortening has to be operated on the ·s ide of the collar with
6.9 _ _ mm
0 15
0.2716 -0.0059 ln .
-""'~
-<I>

NN
do'
(/) 44 mm (1.732 in. dia .). At the 2nd and 3rd refinishing the bush must not be 1
shortened again. Permissible wear: 0.5 mm (0.020
If the bush in an engine which has not yet been refinished, is already 40 mm in.) (at the measuring positions

~~~1-L----~----·------~
(1.5748 in. ) long, it must not be shortened . a, band c)
...::._ Oo
en~
2. Rotor
"'"'
00
dd
The rotor must be replaced if the ring gear is damaged.
Spur pinion (o, Fig . 34) in the magneto side end cover must be replaced together
with the rotor. Fi g. 28

Note:
The rotor is only available together with the needle cage (k, Fig. 37). Original measurement
forKM48 : .
,
~"'U)
<DO
5.5-0.15 mm NN
Fig. 27 dci
0.216 -0.0059 ln.
After decarbonizing the rotor
(see page 25), set new apex Permissible wear : 0.4 mm (0.016
sea ls into the grooves of the in.)
rotor and check the si·d e play (at the measuring positions a, b
with a feeler gauge. and c)
The maximum permissible apex
seal side play is 0.10 mm
(0.003937 in. )
Fi g . 29
Attention!
The apex seal grooves are be-
coming gradually conical; the
feeler gauge is not to be inser-
) For the KM 37/48, the permissible wea r (unevenness) between the measuring
positions a and c : maximum 0.2 mm (0.0079 in .).
ted more than approximately
2 mm (0.078 in.) into the grooves
Fi g . 27 *) Permissible unevenness 0.02 mm (0.00079 in .)
when measuring.
**) Permissible wear up to 0.02 mm (0.0079 in .)

18 19
 b) Sealing pins Replacing the needle bearing (KM 37), the collar bush (KM 48), the spur
pinion and the oil seals.

~"~·
Fig . 30
The sealing pins must be
* _ _ ..,. U"'' evenly worn. Check with a
micrometer.
When working on the end covers, utmost care must be taken not to damage the
sliding surfaces. The smallest damages could lead to seizure of the engine or to
0
l.O_ ~
·-"!
"'
The measurements relate to the leakiness and power loss.
lll 0 0
KM 37 and KM 48. Do not remove minor carbon deposits from the sl iding surfaces of the end covers.
"
.......... f&S4Dll ' 1\l
Remove major carbon deposits carefully.
*) Permissible unevenness 0.05 Inspect the end cove rs for mechanical damages especially at the edges of the ports
Fi g. 30 mm (0.0019685 in .) qind on the sliding paths of the side seals and sealing pins.
**) Permissible wear up to 0.3 If the even faces of the end covers have been damaged by the seals, they can
mm (0.0118 in .) be refinished as outl ined on page 15.

Power take-off side end cover

c) Side seals (KM 37)
)

~
E Fig. 31 Fig . 32
*
/ ~;{~
::::::::::::::::::::::::::::::::::=~ ~ ~~~
The measurements relate to the
KM 37 and KM 48
Orig,inal measurement :
l
Remove circlip (a ), washe r an d
needle cage (k).
Heat the end cover to appro x.
~. :.,~~ 2,4---0,1 mm
150 ° Centigrades (300 ° F) and
press ou t the bush for the need le
(0.0945 - 0.00039 in .) cage.
Fi g . 31 Remove the second washer an d
Permissible wear : the second circlip .
0.2 mm (0.0079 in .) Press out the oil seals.
The side seals should not be
worn more than 0.1 mm (0.0039
in .) at their ends, as compared
F& S 4010o 19 .
with the rest of the side seal.
Fig . 32
d) Apex seal springs, sealing Note:
pin spr-ings and side seal
springs must be replaced at When inserting the circlips, take utmost care that they are perfectly seated m
every disassembly of the their grooves.
eng ine. Insert circlips and place washer.
Heat the end cover (approx 150° Centigrades = 300° F) an d press in the bush .
*) Permissible unevenness 0.1 Before mounting the oil seal , fill its groove with high viscosity g rease (Aivania 3)
mm (0.0039 in. ) and slightly coat the seal ing l·ip.
**) Perm issible wear up to 0.2 Press the seal in flu sh, from outside.
mm (0.0079 in.) Place the needle cage, second washer and insert th e second circlip.

3. Rotor housing
The roto r housing must be replaced, when the elnis il-coating of the sliding su~f~ce
))
has been damaged th rough d irt or foreign matters or when cra cks (not ha1rlme
cracks) are perceptible. ·d ·
When the above mentioned influences are not present, the wear of the sl1 mg
surface is very minor.

Note :
When replacing the rotor housing , the ape x seals a nd their springs must a lso be
replaced by new ones.

21
20
 Power take-off side end cover Eccentric shaft
Fig. 33
(KM48)
Unscrew 3 screws. Bearings of the eccentric shaft
Heat the PTO side end cover Fig. 36
1
(approximately 150 ° Centigra-
des = 300 ° F) and press out Disassembly
the collar bush with oil seal. Remove circlip (x) and needle
Screw 3 studs M 5 x 50 in the cage (a).
end cover, for centering the col- On KM 48, remove circlip and
lar bush . needle cage also on the power
Heat the end cover (approx. take-off side.
150 ° Centigrades = 300 ° F) and Insert the eccentric shaft, as
press in the collar bush to its illustrated through the riveting
stop. stock (repair tool No. 11 ) and
Screw the collar bush tight with remove the tubular rivets (zj
F8540 10:101 3 screws M 5 x 15 (hexagon with riveting tool (repair too
socket head). No. 12).
Fi g. 33
Before mo·unting the oil seal, fill Remove washers (b) and needle
its groove with high viscosity cages (k).
grease (Aivania 3) and lightly
coat the sealing lip. Fig. 37
Press the new oil seal flush.
With a refinished end cover, the Assembly
collar bush must be shortened Slide the needle cage (k) onto
by 1 mm (0.03937 in.), see page the eccentric shaft, place wa-
18. shers (b) (chamfered bores poin-
ting outwards), insert tubular
Magneto side end cover rivets (z) from the magneto side
Fig. 34 (see arrow).
For pressing in and out the spur Place eccentric shaft on rive-
pinion (o), heat the end cover t.ing stock (x) and caulk the rivets
to approx. 150 ° Centigrades with riveting tool; the washers
(300 ° F). (b) must be tight.
For pressing in the spur pinion Fit the needle cage (a, Fig. 36)
(o ), take care of the alignment and insert the circlip (x, Fig. 36).
bore in the pinion and of the On KM 48, mo.unt the neddle
alignment pin in the magneto cage and the circlip also on the
side end cover. ' power take-off side.
Fig . 34 If that end cover has been refi-
nished, see note on page 18.
Note:
If the teeth of the spur pinion
(o ) are damaged, the teeth of
the rotor (h, Fig. 42) must be
inspected and in case of damage
)
the rotor assembly replaced.
When replacing the rotor, pay
attention to the note under 2.
Rotor on page 18.
Bearing cover
Fig . 35
Press the oil seal (1) out of the
bearing cover (2) and press in
the new oil seal, as illustrated,
flush, with the sea·ling lip first.
Fill the groove of the oil seal
with high viscosity grease (AI-
vania 3) and lubricate the seal-
Fi g . 35 ing lip slightly.

22 23
Disassembling, decarbonizing and assembling the rotor. Decarbonizing
Fig . 41
When the rotor seals are stuck in their groves after a long period of running time,
because of carbon build-up, it is advisable to dismantle the rotor as follows : When all seals and springs are
removed, clean the grooves and
Disassembly the seals with the decarbonizing
Fig. 38 tool.
Remove only major carbon
Set the decarbonizing tool (re- build-up (flakes ) from the com-
pair tool No. 15) to the end of bustion chamber faces of the
the apex seal (c) and remove rotor.
the latter and its springs (d) by Do never attempt to scrape the
tapping lightly. rotor faces completely clean to
(Observe page 20, para b and the bright metal.
d) Note:
After decarboni z ing, refer to
the instructions on page 18
) under "2. rotor". Fi g. 41
F&S 4010 :56

F&S 4010 , 53
Fig . 38

Fig . 39 Assembly
Loosen the sealing pin (e) by Fig. 42
turning with the decarbonizing
tool and force it out of its Lubricate the grooves for the
recess. seals lightly with vaseline
Remove the 2 springs under the grease.
sea.Jing pin. ?et two sealinQ pin springs (f)
(Observe page 20, para c and mto each openmg, so that the
d) ends are pointing away from
each othe1· (align slots with
grooves in rotor apex ) and
insert the sealing pins (e ).
Note:
The rotor is shown with only 1
F &S 40 10 :5 4
of its 3 sets of sealing elements,
Fi g . 39
the other two sets are already F&S 4010:22
installed . Fi g. 42
Fig . 40
Remove the side seals (a) by
lightly tapping with the decarbo-
nizing tool.
Remove the side seal springs (b).
Fig . 43
Mount the side seal spring (2,
or b, Fig . 42) in such a manner
that its two outer bows (see
arrows ) come into contact with
the ends of the side seal (1).
Insert the ape x seals (c, Fig. 42)
and the springs (d, Fig. 42) only
b after mountmg the rotor into its 2
F&S 4010:55 housing. F & 5 411t : 141

Fig. 40 Fig. 43

24 25
Decarbonizing the rotor housing Top speed limiting device
The top speed limiting device is fi tted in the fan cover and protects the engine
Decarbonizing from over-speeding.
Remove the carbon build-up carefully from the exhaust port and the spark plug Operation
bore of the rotor housing with a screwdriver or a triangular scraper, taking care The air vane of that device is governed by the cooling air stream. When the engine
that no metal is scraped off. load decreases, the engine speed raises, creating a stronger ai r stream that moves
Cleanse the rotor housing, wash it when necessary. the air vane against the pressure of a spring. This movement is tra nsmitted via a
lever arrangement to the throttle valve of the ca rburettor and reduces or closes
the intake. The engine speed will therefore decrease, producing likewise a smaller
F&S 4010;58 Rep.lacing cooling air stream . The spring turns the air vane back to its original position,
opening at the same time the throttle again.
Fig. 44
The rotor housing must be re- Dismantling
placed, when major chatter Fig . 46
marks, as illustrated, are present
and clogged with carbon depo- Unhook spring (a ), loosen nut
(f) and remove lever (x).
sit. Remove washers (g ) and spring
The sliding surface of the
housing cannot be refinished. (a).
Therefore, a housing with a Remove air vane (e·) with shaft
defective sliding surface must be (I) and washer.
replaced by a new one. Knock out air vane bush (r) with
coppe~ pin, take care of toler-
ance nng.
Remove circlip (k), washer, fork
lever (i), second washer and
Fig . 44 second circl ip.
Press out pivot pin (m).
Note: (c, Fig. 42) F&S '010 ;100
Fig . 46
The new rotor housing must be mounted with new apex seals only, after having Assembly
inspected the apex grooves of the rotor for possible wear (see instructions on
(See Fig. 46)
page 18).
Press pivot pin (m) from the outside into the fan cover to a depth of 19 mm
(0.748 in.) and press the air vane bush (r) with tolerance ring home.
Fit circlip (k), washer, forked lever (i), second washer and second circlip onto the
pivot pin .
Insert air vane with air vane shaft and washer into the air vane bush.
Hook the spring (a ) with its short end into the bore at the air vane bush and fit
Muffler washers (g ).
Slide lever (x) onto the air vane shaft, catching the lug into the recess of the forked
Fig. 45 lever (i). Hook spring (a ) at the lever.
Do never modify or tamper with Adjusting
the inside of the exha.ust system.
Any such modifications not only Fig. 47
have an adverse effect on fuel Lift the air vane up to the stop
consumption, engine performan- pin, set the leve r (2) so that the
ce and noise, but are also lower edge of the fork end of
against regulations and subjE!ct the lever (i, see arrow) is at the
to penalty. same height as the upper edge
of the lever (2), as illustrated.
Press air vane shaft to the out-
side and clamp the lever (2)
tight.
The air vane must operate
easily, w ithout rubbing any-
F&S ~010:2'. where.
Fig . 45 Fig. 47

26 27
Recoil starter Fig. 51
To take out a defective spring ,
knock the starter housing with
Disassembly the open side down on the work
Fig. 48 bench and control its uncoiling
with the housing .
Grip the recoil starter in a vice,
Remove check plate (4, Fig. 52).
as shown in Fig . 49.
Remove circlip (a ), washer (b),
spring washer (c), shims (d ), fric-
tion plate (e ) assembly with driv-
ing levers, shim (f) and circlip
(g).

Note:
On a former recoil starter
model, the spring washer (c) is Fig . 51
fitted underneath the friction Assembly
f e
F&S <.2<.,67 plate and the circlip (g ) is not Fig. 52
Fi g. 48 used.
Note:
When mounting a new bearing
Fig . 49 pin (3), make sure that its flat
Pull the starter cable approx. side (see arrow) points to the
50 em (20 in. ) and lock the cable opening for the cable and paral-
p·ulley with a home-made tool lel to the direction of pull of
(see illustration ). the starter cable.
Lubricate the bearing pin slight-
ly with a film of "Anticorit 5"
oil.
Insert the check plate (4) so that
the bent-up lug (1) is slightly
behind the spring anchoring
point (in starting direction ) and
so that the pressed-out lugs (2)
lock in with the corresponding
ribs on the bottom of the starter
housing .

Fig . 53
Fig. 50
Fit the end of the spiral spring,
Remove the retaining pin out of as illustrated, and insert the
the starter handle and open the spring winding after winding .
clamping sleeve (n) by tapping
with a hammer. Pull retaining
Note:
pin and starter handle from the
starter cable . The first winding of the spiral
Remove locking tool and allow spring must run outside the tab
the cable to recoil into the (1, Fig. 52), whereas all the re-
housing completely. maining windings are inside of
Carefully lift off the cable it. Make sure that the windings
pulley, taking care that the lie flatly on the check plate.
spiral spring remain s in posi- Place holding ring (g ) so that
tion . the riveted end of the spring
Remove ring (g , Fig . 53). fits snugly in the re cess of the
spring.
Coat the spiral spring with a
Fig. 50 film of " Anticorit 5" oil.

28 29
 Fig. 54 Flywheel magneto and magneto generator
Fit cable disc onto the bearing
pin, hook spiral spring !nt'? the Replacing the ignition and
drivin~ tab and mount mcl1p (6, lighting armature.
Fig . 55). . .
Coil the cable pulley w1th sp1ral Fig. 57
spring in the startin~ ~irection 1. Remove dust protective cap.
with the self-made wmdmg tool 2. Pass the cables through a
up to the stop. Release _spiral hole in the centering unit and
spring 1 . .. 2 turns, until the set the armature base plate
recess for the solder nipple in on it.
the cable pulley faces the ope- 3. Position the centering piece
ning in the st.arter housing for and secure the hexagon head
the starter cable . screw by hand .
In that position, lock the cable 4. Remove defective armature
pulley or winding tool with an and replace by a new one.
l appropriate round material. ) 5. Set the centering ring on,
Fig . 54 press the replaced armature
against the centering ring and
Fig . 55 tighten both screws.
After removal of the center-
Insert the starter cable through ing ring, the proper air gap
the cable fitting point (5) in the between the pole shoes and
cable pulley and through the the magneto flywheel has
cable guide (4) in the starter been set.
housing.
Pull the starter cable. Note: Fig . 57
Place the solder nipple in posi- The F & S centering device will
tion , making sure that the flat no longer be available after ex-
face of the nipple, when the haustion of present stocks.
cable is on the pulley, points to New ignition or lighting coils
the starter housing. must be installed according to
Mount the starter handle (3) and the installation directions supp-
the clamping sleeve (2) onto t_he lied with BOSCH spare parts.
cable, wind the cable tw1ce An air gap of 0.25 .. . 0.35 mm
around the retaining bolt (1) (0.00984 ... 0.0138 in.) must be
F& 54010:181
and fasten with the clamping strictly set between the pole
sleeve. shoes and the magneto flywheel,
Fig. 55 Pull the retaining bolt into the in order to achieve the best igni-
starter grip and let the cable tion and lighting efficiency.
wind in.
Replacing the breaker points

Fig. 56
) The contact breaker must be replaced, when the breaker points, sliding bush or
pivot pin are worn or when the bearing bush, breaker point lever or the lever spring
Fit shims and friction disc (3) are damaged.
with driving levers (1), ensuring 1. Unscrew the short circuit cable, observing the proper order of insulating washers
that the driving levers engage for the connecting bracket of the point holder.
in the cable pulley. . 2. Remove safety and point lever from pivot pin (observing shims).
Fit, one after the other, sh1ms 3. Unscrew fillister head screw and remove point holder.
(d, Fig. 48), spring . washer (c, 4. Unscrew pivot pin from armature plate.
Fig . 48), and covenng washer Install new parts in the opposite order, observing the following points :
(2), insert circlip (4). Swage the pivot pin after screwing it in.
Use only the breaker point contact set prescribed for this engine.
The breaker points should be of equal height and parallel to each other after the
Note: installation.
If the driving levers do not move Lubricate the pivot pin with BOSCH grease Ft l v 8, before installing it.
outwards when activating the Lubricate the lubricating pad and the cam follower with BOSCH grease Ft 1 v 4
starter, more shims must be (obtainable in tubes at BOSCH service centers).
fitted on the friction disc (3). Make sure that no oil or grease gets onto the breaker points.
Fig , 56

30 31
Replacing the condenser Bing butterfly-valve carburettor
1. Unsolder both connecting wires.
The carburettor, which consists essentially of the mixing chamber and the float cham-
2. Turn armatwe base plate over and press the condense r out with a wooden dowel. ber, has a flanged connection . The supply of air-fuel mixture to the engine is con-
trolled by means of a butterfly valve.
3. Scrape the high spots on the bore caused from previous swaging.
Fuel is supplied to the carburettor through a flexible pipe. The fuel supply is con-
4. Push the condense r into the bore and swage carefully. trolled by a float needle actuated by an annular float which is laterally pivoted thus
5. Re-solder both wires. enabling an increased closing pressure of the flood needle and an exact cont(ol to
be obtained. The fall from fuel tank to carburettor shou ld not be less than 100 mm
(4 in .). An exeption are engines with fuel pumps ; see section "Fue l Pump". The fuel
Carburettor level is about 4 ... 5 mm (0.157 ... 0.196 in. ) below the edge of the carburettor
housing . Th e float chamber is vented through the primer guide (external venting ).
The type of carburettor to be fitted to the engin e and the choice of its jet sizes are
determined by means of tests carried out at the factory. The carburettor setting,
determined in this way, represents an opimum efficiency setting, and for this reason A Ca (g
it is advisable not to make any changes of your own.
No arbitrary carburettor adjustments are to be made as long as the engine runs
)
smoothly at idle speed, when opening the butterfly valve the engine speed increases
steadily without sputtering or "coughing" and the engine reaches its full output. If
the engine sputters or falters or if black fum es are emitted from the muffler, then the
mixture is too rich. Short blowbacks or an unsteady running of the engine at a given ..r-::-~ o,
speed or the engine back-firing through the carburettor with a blue flame and y,
starting difficulties indicate that the mixture is too lean. OJ
With correct carburettor setting, a correctly functioning air filter and a spark plug IMI-::-I.B-~1\--- X
with the proper thermal value, the insulator of the spark plug should show a r=-----------'~ Wz
mediumbrown color. If the spark plug shows heavy carbon deposits or is oily or '---- - Uz
wet, it means that the air-fuel mixture is too rich. On the other hand, if the spark --- - - w
plug shows a grey or withe color, it is an ind ication that the fuel-air mixture is too
lean . iilii!Mit~-,f--- u
Warning! Do not ad jus the mixture too lean , because with the reduction of the f.uel,
the lubrication quantity is also reduced, thereby endangering the lubrication of the
moving parts. Observe that a reserve of the oil lubrication is present when adjusting
the carburettor.
Fig . 58
Always remember that the engine will run economically only when the carburettor is
correctly tuned.
A carb ure ttor housing 01 throttle arm
c, sprin g Q, choke arm
c. bu tterflv va lve U float chamber
Carburettor adjustment corrections for compensating climatic conditions c. va lve sp indle u, = gasket
When using the eng•i ne at altitudes above 3250 ft. (1000 meters), or in the tropics, G mixing tube V primer button
adjustments to the carburettor setting wil l be required. As the air density is reduced
at high altitudes, (mountains) the supply of fuel to the carburettor should be reduced
by changing the main jet size. In tropical areas, however, the setting should be
)) H
J
K,
main jet
idling je t
air regu lating screw
y,
W
s prin g -primer button
fl oat
W 2 = pin
adjusted, to give a richer mixture. K, spring X float needl e valve
M• choke Y fuel connection
Mn = choke spi ndl e y, gasket
Starting system
On the butterfly valve carburettor the choke is incorporated in the carburettor itself.
The choke should be used to facilitate starting from cold . In warm weather conditions Carburettor adjustment
or warm engine, the choke should be neither partially nor fully closed (only with a
cold engine). Through closing the chok a high vacuum develops in the mixing
!he adjustment .of the carburettor depends on the jet size appropriate to the operat-
chamber producing a rich air-fuel mixture. !ng speed requrred . It can only be corrected by a change of jets (larger or smaller
After the engine has started, open the choke slowly. jets).
On butterfly-valve carburettors, a primer button is sit uated on top of the float Th~ air-fuel mixt ure for idling can be regulated by mean s of the adjustable air regu-
chamber wh ich serves to flood the carburettor in cold weather; when using this, the latrng screw (K 1). The settrng values for normal operating conditions are shown on
instructions given on the fuel tank of the eng•ine should be followed . page 6 under Specifications.

32 33
 Fig. 59 Fuel pump
Attention!
On engines with lever controlled The diaphragm of the fuel pump is activated through the vacuum and pressure,
carburettor and precision gover- which is developed in the intake chamber of the engine, thereby sucking fuel from
nor, the spring (1) is not fitted . the tank and pumping it to the carburettor. The rise of the pump should not exceed
On carburettors with cable con- 153/• in. (0,4 meter).
trol, as illustrate-d, this spring
must be fitted. The fuel pump can be dismantled for cleaning.

Disassembly
Fig. 60
Remove screw (1) with gasket
Fig. 59 ring.
) Remove cover (7), gasket, sieve
(6) and gasket.
Maintenance of the carburettor and air filter Remove the 4 screws and sepa-
At certain intervals every carburettor must be disassembled cleaned and over- rate the pump housing halves.
hauled. All exterior dirt should .b e cleaned off with gasoline' before disassembly. Remove d iaphragm (3) and gas-
T~e holes, .ducts, passages and 1ets. must n<?t be cle~ned with hard objects (e . g., ket.
w1re or drill ), but should only be nnsed w1th gasolme and cleaned by air blast Unscrew nipple (5).
(remove diaphragms prior to blowing out). Before assembly check that all car- Cleanse all parts thoroughly,
buret~or co~ponents (especially jet seats) are in proper working order. check for defects and replace as
The mstruct1ons of the carburettor manufacturers must be observed in every necessary.
respect Fi g. 60
Checking an~ cl~aning the fuel- and air filter in good _time helps to achieve satis- Assembly
factory funct1onmg of the carburettor and longer engme service life (see "Lubri-
cation and Maintenance chart", page 70). ' Set the gasket and diaphragm (3)
onto the pump housing half (4),
so that their contours coincide.
Special maintenance notes Mount pump housing half (2),
1. Make sure that the butterfly valve always functions easily. observing the alignment pins
and secure with 4 screws M 4x12.
2. The hinge attachment of the annular float must on no account be distorted as Mount the gasket and sieve (6,
this will upset the correct fuel level of 4 . . . 5mm (0.157 .. . 0.196 in.) below'the with support ribs to cover 7),
edge of the carburettor housing. gasket and cover (7), secure with
3. Check that float needle valve functions smoothly and is not leaking. screw (1) M 4 x 12 and gasket
ring.
Mount nipple (5).

Note:
The nipple mounted on the cover
(7) is for the fuel line coming
from the tank.
The nipple (5) is for the fuel line
to the carburettor.

Attention!
For KM 37 or KM 48 on MAC
outboard engines, a diaphragm
with special slots must be used
(see Spare Parts List).

The fuel pump with slotted diaphragm is ma rked with a red colour spot, for identi-
fying purposes.

34 35
ASSEMBLING THE ENGINE End cover on power take-off
side.

End cover (magneto side), rotor Fig . 64

housing and rotor. Lubricate all working surfaces
Fig . 61 with an appropriate oil (see
chart on page 72).
Mount· the end cover (magneto Fit the mounting sleeve (b, repair
side) to the mounting jig. tool No.3) and install the power
Place the rotor housing (2), so take-off side end cover (y).
that the spark plug hole is posi- Take care of dowel sleeves (1,
tioned above the intake port. Fig. 61 ).
Fit the dowel sleeves (1). (If the
end covers have been refinished,
observe the instructions on page Fig. 65
15). Screw the engine block together.
Insert the pre-assembled rotor
(3), ring gear downwards.
Take care of sealing elements.
) 15 hexagon head screws
M 6x55
} ?<;
~
Fig . 61
3 hexagon head screws (1) ~
M6x65 ~
15 hexagon head screws } ?<;
M 6x70 ~
Apex seals 3 he xagon head screws (1) &
M 6x78 ~
Fig. 62
with nuts and each two washers
Insert the apex sea I (1) into the (the washers are placed under
groove. the screw head and under the
Place the spring (2), as illustra - nut).
ted, and push the apex seal with Tightening torque 0.7 . .. 0.9 kpm
its spring into the groove. (5.1 ... 6.5 ft lb).
Mount the other apex seals w ith Fit the mounting bracket (2) to
their spring in the same way. the rotor housing.

Grooved ball bearing and bear-

ing cover .
• F&S40101
ftlllll!.. Fig. 66
Fig. 65
Fig . 62 Heat up the grooved ball
bearing (4) and slide it onto the
eccentric shaft.
Insert the circlip (3).

Eccentric shaft )) Note:

Fig . 63 On former engine versions,
determine with a feeler gauge
Engage the rotor (1) with the the play between the inner race
gears and fit the eccentric shaft of the grooved ball bearing and
(2), as illustrated. the circlip (3) and mount shims
as required (see Spare·Parts List).
Place the round sea ling ring (5)
and fit the mounting sleeve (1,
repair tool No.2).
Press on the bearing cover (2)
and screw it with 3 hexagon
socket head screws M 6 x 25 with
copper sealing washers.
Tightening torque 1.1 ... 1.3 kpm
Fig . 63 (8.7 . .. 9.4 ft lb ). Fi g. 66

36 37
 Bracket, fan cover and housing New armature plates do not have markings and must therefore be centered in their
cover. slots. Fasten the armature plate (m) with 3 Philips type screws M 4 x 14 with washers.
Fig. 67 Tightening torque 0.2 .. . 0.3 kpm (1.4 ... 2.1 ft lb).
Slide the protective cap {x, Fig 68) onto the ignition cable. Screw the suppressor cap
On KM 37 engines, screw the {k, Fig. 68) on the ignition cable and pull the protective cap over the suppressor cap.
connecting tube (z) to the Unscrew the protective cap (r, Fig. 68).
magneto side end cover. Mount the magneto flywheel (with fan on KM 37), onto the eccentric shaft, guiding
Take c;:are of the position of the the key into the keyway in the flywheel.
bracket (g).
Insert the dowel sleeves.
Mount the fan cover (x) with the Timing the ignition.
overspeed control and the hous-
ing cover (a ) and screw them It is recommended that the ignition system be checked each time that the engine is
tight with serviced, as the engine performance depends on it and various tro·ubles in the
lighting system are caused by an incorrect ignition setting.
5 hexagon head screws } ~ The spark plug gap is also to be inspected and when necessary adjusted to 0.5 mm
M6x90 3: (0.020 in.).
1 st ud w
Fi g. 67
M 6x 145 ..:::::! ) Spark advance:
Contact breaker gap:
10 ° .. . 12 ° before top dead center.
0.4±0.05 mm (0.016 ± 0.002 in.)
5 hexagon head screws } ~ Pole shoe gap: 7 . . . 10 mm (0.276 ... 0.393 in .)
M 6 X 105 3: Measuring instruments : feeler gauge 0.4 mm (0.016 in .)
1 stud J>..
M6x158 ~
Marks for setting the ignition on
with nuts and each with 2 wa - KM 37.
shers.
Tighten ing torque 1.0 ... 1.2 kpm Fig. 69
(7.2 0 8,6 ft Ib).
0 0
Marks are punched on the fan
On KM 37, fasten bracket (g) with 2 hexagon head screws M 5 x 15 with washers. wheel and on the fan hou sing.
Place the gasket and fasten the cover plate or the fuel pump with 2 hexagon head The mark (x) on the fan wheel
screws M 5 x 15 with washers and nuts. coincides with the "0" when the
Note: rotor is at top dead center,
On KM 48 engines, the cover plate or fuel pump is fastened to the rotor housing. the mark (x) on the fan wheel
Flywheel coincides with "M" at the firing
Insert the key into the eccentric shaft. Degrease the tapers on the eccentric shaft position .
and in the flywheel.
Mount flywheel (h, Fig . 10), hold it with hook wrench (n, Fig. 10), and secure with
nut M 20 x 1 and washer.
Tightening torque 7.5 ... 8.0 kpm (56.4 ... 57.8 ft Ib). ,f&S~~
Armature plate and magneto Fi g. 69
flywheel
Fig. 68
Degrease the tapers on the ec-
centric shaft and in the magneto Marks for setting the ignition on
flywheel. In sert the key into the
eccentric shaft.
) KM 48.
Guide the ignition and contact Fig. 70
breaker wires, protected by a Marks are punched on the
heat-resisting tube, together with magneto flywheel and on the
the rubber grommet (b) through bearing cover.
the aperture. Mount the rubber "0" coincides with the notch
grommet block, taking care that {x) or chisel mark on the bearing
it is correctly seated. cover, when the rotor is at top
Slide a second heat-resisting dead center,
protective tube (n) and the rub- "M" coincides with the notch (x)
ber grommet (a ) onto the ignitior~ or chisel mark on the bearing
and contact breaker wires. cover at the firing position.
Mount the rubber plug (take
care of correct seat).
Secure the armature plate, pay-
Fi g. 68 ing attention to the marks (s).

38 39
Adjustment procedure for ignition setting:
1. When cam is at its highest position, adjust contact breaker gap (b, Fig. 71) to
0.4 ± 0.05 mm (0.016 ± 0.002 in. ).
T Starter bell KM 37
Fig. 73
2. Turn magneto flywheel against direction of rotation until the marks for the firing Place the cover plate onto
moment coincide (Fig. 69 and 70). magneto flywheel and fasten
3. Turn magneto flywheel lightly into direction of rotation; now the contacts should the starter bell {1) onto the
begin to open. If not, the firing time can be adjusted. by turning the armature magneto flywheel with 3 hex-
base plate within its slots. agon socket head screws (2) M
Turning the armature base plate against direction of rotatio n of the magneto 6 x 10 and spring washers.
flywheel advances the ignition, turning it in direction of rotation retards the Tightening torque 1.2 ... 1.3 kpm
ignition. (8.7 ... 9.4 ft lb )
4. Always tighten the screws of the armature base plate wel l after such an
adjustment.
5. If the ignition is correctly timed, the pole shoe gap {a, Fig. 71 ) at the firing
position must be between 7 . . . 10 mm {0.276 .. . 0.393 in .).
Fan housing and recoil starter.
Fig . 71
Fig. 74
The pole shoe gap is measured
where the magnet in the fly- Fit 2 dowel sleeves into fan
wheel leaves the armature shoe 1
cover.
edge of the ignition armature; Mount fan housing (p) and fasten
(in direction of rotation of the it with 3 hexago n socket head
magneto flywheel ). screws M 6 x 30 with spring wa-
Should the pole shoe gap be shers.
incorrect, it can be corrected by Tightening torque 1.2 . . . 1.3 kpm
slightly adjusting the contact (8.7 ... 9.4 ft lb).
breakers in the range of Fasten recoil starter {a ) with 4
0.016 ± 0.002 in . (0.4 ± 0.05 mm ). hexagon head screws M 6 x 15
and spring washers.
On stationary engines fit the
pedestal plate with 4 hexagon
Fig. 7l socket head screws M 10 x 25.
~emove engine from mounting
After having adjusted the ignition, remove flywheel, screw on dust protector cap pg .
(r, Fig . 68) and replace magneto flywheel, guid ing the key in the keyway of the
magneto flywheel. Fit spring washer, screw collar nut M 10 x 1, place hoo k wrench Carburettor
(k, Fig . 8) into the magneto flywheel and tighten the collar nut.
Tightening torque 4.3 .. . 4.5 kpm (31 .1 . .. 32.5 ft lb ). Place gasket onto intake p ipe and fa~ten carburettor with intake pipe with
2 he~agon socket head screws M 6 x 20 w1th spnng was hers, after having engaged
Fan wheel KM 48 the p1n of the throttle valve lever into the fork end.
Fig. 72
When the throttle valve is open, the air vane must touch its stop pin . If necessary,
Place the fan wheel in such a
manner onto the magneto fly-
wheel that the notch on the fan
])f slacken the governor lever and adjust the air vane.
Fuel tank
I
wheel (2) coincides with the red On stationary engines, screw on the b racket with fuel tank.
colour mar k (1) on the magneto
flyw~e el. I Mount
Air cleaner
the air cleaner to the carburettor.
Attent·ion!
If there is no colour mark, mount
Muffler
the fan wheel so that its notch is
in line with the keyway in the Fit gasket, fasten muffler with 2 hexagon socket head screws M 6 x 20 with spring
magneto flywheel. Disregard washers.
produces heavy vibrations. Mount the plugs.
Fasten the fan whee l wit h 3
hexagon socket head screws M
6 x 10 with spring washers. Note:
Tightening torque 1.2 . .. 1.3 kpm By fitting an intermediate flange (see spare parts list), the muffler can also be
Fig. 72 (8.7 .. . 9.4 ft Ib). fitted in a horizontal position.
40
41
INTERMEDIATE FLANGE AND FLANGE SHAFT SINGLE AND TWO-STAGE GEARBOX
Direction of rotation
When fitting a single stage gearbox, the direction of rotation of the output shaft
Note: of the gearbox is inversed .
Intermediate flange and flange shaft are used in conjunction w ith single or two- If, for ex<;~mr:>le, the power t?ke -off sh~ft turns counter-clockwise and a single stage
stage gearbox and lever-opera~ed clutch K 160. . . . . . gearbox IS f1tted to the engme, the d1rection of rotation of the output shaft of the
Before removing the intermed1ate flange , pull the dnvm_g pm1on as desmbed on gearbox will be clockwise.
page 43. When fitting a two-stage gearbox, the direction of rotation of the output shaft of
the gearbox is the same as that of the eng ine .
Removal
Removal
Fig. 75
Fig. 77
Unscrew inte rmed iate flange {1)
and flange shaft (2). On gearboxes with oil fill ing ,
remove oil dra ;, , plug an d oil
fill plug and drain the oil.
) Unscrew the nuts (b) with spring
washers and remove the gear-
box.

Fi g. 75
Fig. 77
Driving pinion
Fig. 78
Hold the pinion (2) with a strap
wrench and unscrew nut with
spring washer.
Pull the driving pinion (2) with
puller sleeve (4), clamping ring
Fig . 76 {3) and puller shells (1 repair
For pressing in and out the oil ' tools No. 16, 17 and l8) and
seal (1), heat the intermediate remove key.
flange to approx. 100 ° Centi-
grades (212 ° F.).
Press the oil seal, with its lip
foremost, flush as illustrated.
Fig. 78
Disassembly of single stage
gearbox.
Fig . 79
Unscrew the nuts and rem ove
the spring wa shers.
Remove the round sealing ring
Fi g. 76 (1).
Separate the gearbox (2) by
Assembly screwing 2 screws M 8 x 80 and
Fit the flange shaft (2, Fig. 75) onto the centering _rim of the flywheel and fasten remove gasket.
with 6 hexagon socket head screws M 6 x 14 and sprmg washers. Take care of dowels.
Tightening torque 1.2 ... 1.3 kpm (8? . . . 9.4 ft lb): . Heat up gearcase cover and/or
Mount the intermediate flange (1, F1g. 75) and t1ghten w1th 6 he xagon socket head gearcase to 100 ... 150° Centi -
screws M 6 x 20 and spring washers. ' grade (212 . . . 300 ° F.) and re -
Tightening torque 1.2 ... 1.3 kpm (8.7 ... 9.4 ft lb). move mainshaft assembly. Fi g. 79

42 43
 Fig. 80 Fill gearcase with appropriate quantity of lubricant (see lubrication chart on
page 70).
If the grooved ball bearings
remain on the main shaft, these Disassembly of two-stage gear-
can be taken off with a conven- box.
tional extractor or by means of
2 large screwdrivers. Fig. 82
Heat ··up the gearcase cover in Unscrew nuts and remove spring
which the ball bearings are washers.
lodged and then remove latter. Remove round sealing ring out
Press the oil seal out of the of the gearcase.
gearcase cover. Heat the gearcase cover to 100 °
. . . 150 ° Centigrades (212 . ..
Note: 300 ° F) and separate it with 2
For replacement, gear wheels screws M 6 x 80.
and shafts are only supplied as Take care of dowel sleeves.
a unit. Remove gasket.
Fig . 80 Clean and inspect parts; replace
)
r faulty parts. Fig. 83 F&S 430<117 j
If the grooved ball bearings re- Fi g. 82
main on the main- or inter-
Assembling the single stage ' mediate shafts, p·ull these with
gearbox. a conventional bearing puller
Fig. 81 or with 2 strong screwdrivers
(see Fig. 80).
Heat up ball bearing (f ) to about Remove the shims (k) from the
125 ° C (250 ° F) and press into mainshaft, washer (m, 0.5 mm =
position on the short end of the 0.020 in . thick) and deflector disc
main shaft (d ). (z) from the intermediate shaft.
Fit main shaft (d ) with pressed- Heat the center section of gear-
on bearing into gearcase (a ) case to 100 ° ... 150 ° Centi-
which has been heated up to grades (212 . . . 300 ° F) and
about 100 . .. 150 ° Centigrades remove mainshaft.
(212 ... 300 ° F).
F&S 4010o96 Press in 2 adjusting sleeves (h)
t ·-· =-"
and replace gasket (c). Fig. 84
Fig. 81
Unscrew nut (1) with spring
Measuring the end play of the mainshaft.
washer. Fig. 83
(letters refer to Fig. 81 ) Detach gearcase housing from
End play 0.1 ... 0.3 mm (0.0039 ... 0.0118 in. ) the center section of the gear-
Example: case by means of 2 screws M
Distance from sealing surface of gearcase cover (b)
to bearing seat 20.0 mm (25/32 in. ) 8 x 80, as shown in Fig. 79.
Remove gasket.
Distance from wheel hub of the gear wheel
(a ) to sealing surface (with gasket)
)) Take care of dowel sleeves.
Heat gearcase to 100 ° ... 150 °
of gearcase housing 4.9 mm (3h6 in. )
+ 14.0 mm (9 h6 in. )
Centigrades and remove inter-
Width of bearing mediate shaft.
18.9 mm 18.9 mm ('/• in. ) If the grooved ball bearings
Difference - -1.1 mm (3/641ri':) adhere to either the mainshaft
End play - 0.2 mm (0.0079 in .) or intermediate shaft, remove
Difference to be compensated 0.9 mm
1
( /32 in. ) them with a conventional puller
or w1th 2 strong screwdrivers
The difference of 0.9 mm (1/32 in. ) is to be compensated by shims (I) on the main {see Fig. 80).
shaft (d ). Press the oil seals out of the
Heat up second grooved ball bearing (f) to about 120 ° C (250 ° F) and slide it home gearcase cover.
onto the mainshaft (d). Fig . 84
After the bearing has cooled, heat up the gearcase cover (b) to about 100 . .. 150 ° Note :
Centigrades (212 ... 300 ° F), press it on and secure it with 3 nuts M 8 and spring
washers. Press in oil seal (g ) so that it is flush with the outer edge of the gearcase For replacement the gear wheels and the shafts are supplied only as assemblies.
cover (b ) and fit round sealing ring (1, Fig. 79). Clean all parts, check for possible wear and replace as needed .

44 45
 Measuring the end play of the
Reassembling the two-stage gearbox.
mainshaft
Measuring the end pl a y of the End play : 0.1--0.3 mm
d intermediate shaft. (0.0039--0.0118 in.)
End play: Fig. 86
0.1--0.3 (0.0039--0.0118 in.) Replace gasket (b ) and fit ad -
Fig . 85 justing sleeves (f ).
Fit gearcase housing (b) with
gasket (a ) and gearcase centre
"/
section (m) together, replace

o~~ - /·B
g asket (c).

Fig. 86

z X U F&S '010, 10 7
Example:
Fi g. 85
Distc;mce from the seal ing surface of the g e arcase cover
(d, F1g . 85) to bearing seat (r3, Fig . 85) 28.0 mm (F/64 in. )
Distance from shoulder of the gear wheel (a ) to the sealing
su_rface of the gearcase centre section and the bearing
w1dth of the grooved roller bearing (r3, Fig. 85) - 27.2 mm (15/64 in. )
Existi~g . end play 0.8 mm (1h2 in .)
Perm1ss1ble end play - 0.2 mm (0.0079 in .)
Example: Difference to be compensated 0.6 mm (0.024 in. )
Distance from sealing surface of the gearcase
centre section (m) to bearing seat (r 1) 64.4 mm (2 17h2 in. ) The difference of 0.6 mm (0.024 in .) is to be compensated by shims (k) on the main -
Distance from sealing su rface of the gearcase cover (d) shaft.
to bearing seat (r 4) + 25.6 mm (1 in. )
Fit centrifugal disk (z ) with the raised tr iangle downwards and allow to engage
90.0 mm (335/64 in. ) with the toothing.
Distance of the intermediate shaft (u) from the wheel hub
with centrifugal disk (x), washer (z) 0.5 mm (0.019 in.) Fit washer (ml, 0.5 ml!l (1/64 in. ) thick, hea! up grooved ball bearings (r3 and r4, Fig . 85)
to about 120 Cent1grades (250° F), sl1de onto intermediate and main shafts and
thick allow to cool.
bearing width of the two grooved ball 60.8 mm
bearings (r 4 and r 1) + 28.0 mm - 88.8 mm (3112 in. ) Heat gearcase cover (d, Fig. 85) to about 100 . . . 150 ° Centigrades (212 . .. 300 ° F),
Existing a xial play 88.8 mm 1.2 mm ( 3 /64 in .) • refit and secure with 4 nuts M 8 and spring washe rs.
Permissible a xial play 0.2 mm (0.0079 in .)
Press the oil seal (g, Fig. 81 ) in flush with the outer edge of the gearcase cover
Difference to be compensated 1.0mm ( 1h2 in .) and install round sealing ring (1, Fig. 79).
The difference of 1.0 mm (1/32 in .) is to be compensated by sh ims (s) on the inter- Screw in the oil d rain plug with sealing washer and oil fill plug.
mediate shaft (u). . . . Fill the gea rbo x with the appropriate quantity of lubricant (see Lubrication and
Heat up grooved ball bea ring (r 1) to about 120 ° Centlgrades (250 ° F), sl1de 1t onto maintenance Chart, page 70).
the intermediate shaft up to the large gear wheel and allow to cool.
Heat up the gearcase housing (b ) to 100 ·.·. 150 ° Centigrades (212 ... 300 ° F) and Installing
fit intermediate shaft with pressed-on bea n ng . 1
Fit key into the flange shaft.
Fit adjusting sleeves (h) and replace gasket (a ).
Degrease the tapers of the dr ive p inion and of the flange shaft.
Fit on gearcase centre section (m) and screw on nut M 8 (1, Fig . 84) with spring
Fit drive pin ion (2, Fig . 78), hold it w ith strap wrench and fasten with nut M 14 x 1.5
washer. and lock washe r.
Heat up grooved ball bearing (r2 ) to about 120 ° Centig rades (250 ° F), slide it onto
Tightening torque 5.4 ... 5.6 kpm (39.1 ... 40.5 ft lb).
the mainshaft (v) and allow to cool.
Heat up gearcase housing with centre section to about 100 : .. 150° Centigrades Mount single o r two-stage gearbox (take care of round sealing ring m gearcase)
(212 ... 300° F) and fit in the mainshaft (v) with pressed-on beanng . and fasten with 4 nuts M 8 (b, Fig. 77) and lock washers.

47
46
PRECISION GOVERNOR KM 48 Fig . 90
1st version up to engine No. 6440 768. Place the support with the
Removal. governor head (g ) on an appro -
priate tube and press the go·
Fig. 87 verner head out with an appro -
Unscrew air cleaner (a ), guard priate thrust bolt.
(b) and recoil starter (c). Remove steel belt pulley (p) from
Pull off fuel hose (n). the support (g ).
Prop up support and press out
grooved ball bearing (m).
Note:
The steel belt pulley (p ) has
been superseded by an alu -
minium belt pulley and is inter-
changeable .
Pressing in the governor head
Fig. 90
with the aluminium belt pulle y
is described under Fig . 93.
'Fig. 87

Fig. 88
Disconnect governor rod (d )
from throttle lever and unscrew
governor ho:u ~ing (e ).
Remove gasket.
Unscrew governor guard (r) and
cover with adjusting screw (y).
Take out thrust pin (f, Fig . 89).
Unscrew support (g) and remove Fig. 91
flat belt. Pull grooved ball bearing (o )
with conventional puller (for
e xample KUKKO-puller No.
20-1 ).
Press out shaft (x) and remove
both tolerance rings (n).
Clean all parts, check for pos-
Fig . 88 sible wear and replace as nee d-
ed.
Dismantling the precision governor
Fig . 89
Unscrew both adjust ing nuts (h)
w ith the adjusting sleeve (repair
]l
I
tool No. 7), remove governor
springs and spring cups. j Fig . 91
Unlock crossbolt (i) and remove
it, ta king care of the washers.
I Assembling the precision governor.
Press the grooved ball bea ring 608-2 RS (m, Fig . 90) home into the support (g,
Fig. 90).
Slide tolerance rings (n, Fig. 91 ) onto shaft (x, Fig. 91 ) and press the shaft home
into the governor head.
Fill grooved ball bearing 608 RS (o , Fig . 91 ) with high temperature grease Alvania 3
and heat the bearing to approx. 100 ° Centigra.des (212 ° F) and press it on, seal,ing
Fig . 89
plate facing outwards (using a tube for driving the inner race of the bearing ).
49
 Pressing the governor head with PRECISION GOVERNOR KM 48
steel belt pulley 2nd version from engine No. 6440769 on
Fig. 92
Attention!
Place belt pulley in the support, On engines with the following serial Numbers, the parts for the 1st version, support
fit spacer sheets (s). (g, Fig. 90), governor shaft (x, Fig . 91 ) and grooved ball bearing (m, Fig. 90) are
Press the governor head (k), fitted:
until the shaft is flush with the Engine No. : 6440 781 . . . 6440 785, 6440 823 .. . 6440 826, 6440 918 .. . 6440 937.
grooved ball bearing (m, Fig .
90). Removal
Fig. 94
Unscrew air cleaner (1), guard (2)
and recoil starter (3).

Fig. 92
)

Pressing the governor head with

aluminium belt pulley
Fi g . 94
Fig. 93
Place belt pulley (2) in the sup- Fig. 95
port, screw in two hexagon head Disconnect governor rod {1) from
bolts M 6 x 30 as illustrated. throttle lever and unscrew go-
vernor housing (5).
Note: Remove gasket.
Supporting areas of the screws Unscrew governor guard (2) and
must coincide with the support- cover with adjusting screw (4).
ing area of the cover plate. Take out thrust pin (3, Fig. 102).
Press the governor head (1), until Unscrew support (6) and remove
the shaft is flush with the flat belt.
F & 54.010:184 grooved ball bearing {m, Fig .
Fig. 93 90).

Fi g. 95
Dismantling the precision governor
Assembling the governor head.
Fig. 96
Fit crossbolt {i, Fig. 89), mount washers and secure.
Fit both spring cups and the appropriate sets of governor springs (see chart on Unscrew both adjusting nuts {2)
page 55) and screw both adjusting nuts (h, Fig. 89) flush with the ends of the with adjusting sleeve {3, repair
spindle. tool No. 7), remove governor
springs and spring cups.
Unlock cross bolt (1) and remove
Installation it, taking care of the washers.
Fasten support (g, Fig. 90) with 3 hexagon socket head screws M 6 x 20 and lock
washers, fit thrust pin (f, Fig. 89), the collar facing outwards.
Fit flat belt and check its tension . If necessary, fit shimming sheet (F & S Part
No. 2744 016 000) between support and fan housing.
Place gasket for governor housing.
Fasten governor housing with fitted governor rod (d, Fig. 88) to the support, with
2 fillister head screws M 6 x 18 and lock washers. F B. 54010:168

Adjust governor rod as described on page 54. Fig . 96

50 51
 Fig. 97 Fig. 100
Place the support with the go- Fit circlip into support (1 ).
vernor head (2) on an appro- Fill grooved ball bearing with
priate tube and press the go- high temperature grease Alvania
vernor head out with an appro- 3 and press governor shaft with
priate thrust bolt. governor head home into the
Remove belt pulley (1) and sup- support.
port (2), take out governor head
(3).
Remove the circlip out of the
support, prop the support and
press out the grooved ball bear-
ing.

Fig . 100
Fig. 97

Fig. 101
Fill grooved ball bearing (3) with
high temperature grease Alvania
Fig. 98 3 and press it in, sealing plate
Pull the grooved ball bearing on top.
(1) with a conventional puller Press flat belt pulley (1) flush
(for example KUKKO-puller No. with the shaft (2).
20--1 ).
Press out shaft (2) and remove
both tolerance rings (1 and 2,
Fig . 99).
Clean all parts, check for pos-
sible wear and replace as need-
ed.
Fig . 101

F & S t. 014:l6

Fig. 98 Fit cross bolt (1, Fig. 96), mount washers and secure.
Fit both spring cups and the appropriate sets of governor springs (see chart on
page 55) and screw both adjusting nuts (2, Fig . 96) flush with the ends of the
spindle.

Assembly Installation
Fig . 99 Fig . 102
Slide both tolerance rings (1 and Fasten support (2) with 3 hexa-
2) onto shaft (4). Press shaft (4) gon socket head screws M 6 x 20
home into the governor head (5). and lock washers.
Heat grooved ball bearing (3) Fit thrust pin (3, the collar facing
to approx. 100 ° Centigrades outwards).
(212 ° F) and press it home onto Fit flat belt (1) and check its
the shaft, sealing plate foremost tension.
(using a tube for driving the If necessary, fit shimming sheet
inner race of the bearing). (F & S part No. 2744 016 000) be-
tween support and fan housing.
F & 5£.014:27

Fig. 99 Fi g. 102

52 53
 How the governor works
Fig . 103
Coat gasket w ith sealant No. 40, The centrifugal precision governor is designed for applications where a high
(F & S pa rt No . 0999107 000) an d governing accuracy is required. Th is amounts to ± 2.5 %, represent ing a range of
2925 ... 3075 1/ min for a speed of n = 3000 1/ min.
place governor housmg.
Fasten gover nor hous ing (2) with The centrifugal precis ion governor is driven by a flat belt pulley machined onto the
fitted governor rod (1) to the starter bell , a flat belt and a pulley pressed onto the governor shaft.
support with 2 fillister head
screws M 6 x 18 and lock wa- On the governor shaft is mounted the so-called governor head. This consists of
2 movable flywe ights that are kept pressed together with springs.
shers.
When the engine starts up without load and tends to e xceed the specified speed,
the flyweights move outwards as fa r as the sp rings, which are selected for the
required speed, will allow.
The movemen t of the flyweigh ts is transmitted over a lever system to the carburettor
linkage, wh ich in turn act ivitates the butterfly valve decreasing the open ing in the
mixing chamber. The result is a rpm reduction ; the spring force on the flyweights
Fig. 103 becomes grea te r than the centrifugal fo rce, push ing the flywe ights togethe r, opening
Adjusting the governor rod
the butterfly valve .

Fig . 104 and 105

Open throttl e va lve and slacken
Sets of springs for precision governor.
qovernor lever (I).
Push plate (k) inwards up to the
stop and hold it. Revo lutio ns for Par t num ber O uter Wire Colour Qty. Com·
Distance "a" = 3 mm (0.118 e ngin e ru nni ng diameter th ickness ma r k me nt s
in.) Fig. 105 must be set between
top edge of the rod and top load
I
wi th o ut w it h f ul l
l oad mm I in. mm I in .
edge of the bore (in the go-
vernor lever).
Tigthen governo r lever (I). 3150 3000 12739 009 000 9.0 0.35.43 0.8 0.0315 bl·ue 2
Unscrew governor housing (e),
fasten guard (2, Fig . 95) ~ith
0939 010 006 12.1 0.4763 l.O 0.0394 violet I2
I

plug to the governor housrng 3550 3400 2739 006000 9.2 0.3621 0.9 0.0354 grey 2
with 2 fillister head screws M 0939 010006 12.1 0.4763 l.O 0.0394 violet 2
5 x 20 and lock washers. 3750 3600 2739 006 000 9.2 0.3621 0.9 0.0354 grey 2
Fig. 104
Watch for correct seat of the 2739 010000 11.7 0.4606 0.9 0.0354 red 2
bellows.
Fasten governor hous ing again 4200 4000 0939 010007 12.4 0.4882 1.2 0.0472 blue 2
to the support. 0939 009 008 9.4 0.3700 0.8 0.0315 brown 2
Hook governor rod into throttl e
lever. 4700 4500 0939 009008 9.4 0.3700 0.8 0.0315 brown 2
Fill governor housing with 15 cc 2739 005 000 12.3 0.4842 1.3 0.0512 g reen 2
(0.528 fl oz) engine oil SAE 40
for summer operation or SAE 10 ))
for winter operation .
Fit gasket and fasten cov~r (4)
with adjusting screw wrth 2
countersunk head screws M
5 X 10.

Note :
Unsc rew a djusting screw (3, Fig.
95) a s fa r as possible.
Fig. 105

Fit recoil starter with 4 he xagon head screws M 6 x 15 and lock washers.
Fasten guard (2, Fig . 94 and b, Fig . 87) with 2 or 3 he xagon socket head screws
M 6 x 10 and lock washers.
Mount air cleaner to carburettor.
55
54
 [

Disassembling the intermediate flange.

CENTRIFUGAL CLUTCH (with gearbox)
Fig. 109
Removal
Grip pinion in a vice (use pro -
Fig. 106 tective jaws) and ·unscrew nut
Unscrew nuts (b) with lock wa- with lock washer.
shers. Remove single- or two- P·ull pinion with puller sleeve,
stage gearbox. Unscrew inter- clamping ring and puller shells
mediate flange (k). (1, 3 and 4, Fig. 78).
Remove key.

)
Fi g. 106
Fig. 110

Fig . 107 Remove circlips (a and k) and

press out clutch case.
Unscrew c;lisc (h). Remove second circlip, warm up
Force off 4 flywe ights (a ) with intermediate flange and press
screwdriver. out both grooved ball bearings.
Take care of springs.

Note:
If the springs went off during
forcing off the flyweights, see
page 59 for fitting .

F&S 4010:!L
Fig:-110

Fig . 107 Assembling the intermediate flange.

Insert circlip (k, Fig. 110).
Heat up intermediate flange, fill grooved ball bearing with high temperature
Fig . 108 grease (Staburags NBU 30) and press it in in such a way that the sealing plate faces
o·utwards. Fit second circlip, press clutch case and mount circlip (a, Fig . 110).
Pl ace hoo k wrench (1, repair tool Fit key and degrease tapers of shaft and pinion. Mount pinion, grip it in a vice
No . 10) w ith its long bolt be- (use protective jaws) and fasten with nut M 14 x 1.5 and lock washer.
tween the straight face of the Tightening torque 5.4 .. . 5.6 kpm (39.1 . .. 40.5 ft lb).
fly wheel and the housing cove r
und un screw hub (2). Installation
Re mo ve w asher. Fit disc without holes onto eccentric shaft, place hook wrench (1, Fig. 108) and
fasten hub (2, Fig . 108).
Tightening torque 7.5 .. . 8.0 kpm ).
Drive 4 flyweights with both springs by light blows (rubber mallet) onto the hub
and fasten disc (h, Fig. 107) with countersunk screws M 5 x 8.
Intermediate flange and gearbox
Screw intermediate flange (k, Fig . 106) with 6 hexagon head screws M 6 x 25 and
lock washers.
Mo·unt single stage or two-stage gearbox with 4 nuts M 8 and lock washers.
Fig . 108
57
56
CENTRIFUGAL CLUTCH (without gearbox) Replacing the grooved ball
bearings
Removal Fig. 114
Fig . 111 Pull one of the two grooved ba ll
bearings (m) with an internal
Remove circlip (a ) and pull clutch puller.
case (slide fit). Take care of Press the second grooved ball
washer (1 mm = 0.039 in. thick). bearing out.
Fill the grooved ball bearing
with high temperature g rease
(Staburags NBU 30) and p ress it
in, so that the sealing plate
faces outwards. m

) Fi g. 11 4
F&S 4010,112 .

Fi g. 111
Fitting the flyweight springs
Fig. 112 Fig . 115
Remove washer (h). If the clutch case is available,
Force off 4 flyweights (a) with Place the flyweights in it and
screwdriver. fit the springs.

Note:
If the springs went off during
forcing off the flyweights, see
page 59 for fitting .

Fig. 11 5

Fig. 11 2

Fig . 113 )) Fig . 116

If the clutch case is not available,
Place hook wrench (1, repair able, bind the flyweights to-
tool No. 10) with its long bolt ge·t her with a wire and fit the
between the straight face of the springs.
flywheel and the housing cover
and unscrew hub (2).
Remove washer.

F&S 4010,114 I
Fi g . 11 3 Fig . 116

58 59
Installation Clutch plate
Fit the disc with large bore onto the eccentric shaft, place hook wrench (1, Fig . 113) Fig. 119
and fasten hub (2, Fig. 113).
Hold clutch plate with hoo k
Tightening torque 7.5 . . . 8.0 kpm (54.2 ... 57.9 ft lb). wrench (2, repair tool No . 10/.
Drive the 4 flyweights with both springs by light blows (rubber mallet) onto the Unscrew nut (3) and re move ock
washer.
hub.
Fit disc with small bore onto the hub, place check plate, after having lightly
lubricated it, in the clutch case.
Slide the clutch case onto the hub and fit circlip.

LEVER-OPERATED CLUTCH K 160 )

Removal Fig. 120

Fig. 117 Fit protective cap (repa ir tool
Unscrew power take-off side (x) No. 6) onto threaded end and
of clutch case. mount puller (2, repair tool No .
9) with 2 hexagon screws M
8x60.
Hold dutch plate (3) with hook
wrench (4) and pull it off).
Unscrew puller (2).
Remove key, unscrew engine
side half of clutch case (1).

Fig . 120
F&S4010:~2 ~

Fig. 11 7

Cover assembly Disassembling the power take-

Fig. 118 )) off side of clutch case.
Fig. 121
l

Unscrew cover assembly (y),

taking care of cylindrical pins (1, Remove springs (k) and release
Fig. 119). bearing (x).
Remove driven plate.
Pull grooved ball bea ring with
conventional puller (for e xample
KUKKO internal puller No. 21 /2
with support No. 22-1 ).

F&S 4010 • 81
L ."
Fig . 11 8

60 61
 Fig. 122 Installation
Chase sleeves (k). Mount engine side of the clutch case (1, Fig. 120) and tighten with 4 nuts M 8 and
Pull out shaft with clutch lever, lock washers.
taking care of the round sealing Fit key to the flange shaft.
ring . Degrease tapers of clutch plate and flange shaft.
Screw stud (a ) M 5 into the shaft, Mount clutch plate (3, Fig. 120)h hold it with hook wrench (4, Fig. 120) and fasten
grip it in a vice and pull the with nut M 14 x 1.5 and lock was er.
shaft out. Tightening torque 5.4 .. . 5.6 kpm (39.1 . .. 40.5 ft lb ).
Remove release fork (z), ret-urn Press grooved ball bearing home into the clutch plate.
spring (m) and shims. Mount driven plate and center it with home-made centering bolt.
Remove circlip (y), shims and Fit both cylindrical pins (1, Fig. 119) into the clutch plate, mount cover assembly
sealing washer. (y, Fig. 118) and tighten with hexagon head screws M 6 x 18 and lock washers.
Press the spigot shaft (i) to the Tightening torque 0.8 ... 1.1 kpm (5.8 . .. 7.9 ft lb ).
a outside, remove deflector disc. Fit power take-off side of clutch case (x, Fig. 117) and tighten with 4 nuts M 8 and
lock washers.
F&S 430o113
Fig. 122 ) DEVICE FOR HEATING THE INTAKE AIR
Fig. 124
Fig. 123 The 1st version is mounted onto
Remove circlip (p). the fan ho-using.
Heat up power take-off side of
the clutch case to approx. 100 °
Centigrades (212 ° F) and press
out the grooved ball bearing.
Clean all parts, check for pos-
sible wear and replace as need-
ed .

F&S40.l0:162
L.
Fig . 124
I
Fig. 125
Fig. 123
The 2nd version is mounted be-
tween muffler and rotor housing
with 2 gaskets.
Assembling the power take-off side of the clutch case.
Heat the power take-off side of the clutch case to approx. 100 ° Centigrades (212 °
F) and press the grooved ball bearing home (use protective block).
Fit circlip (p. Fig. 123).
Place deflector disc on grooved ball bearing and press the spigot shaft in .
Place sealing washer and shims (as required ).
Fit circlip (y, Fig. 122).
Place release bearing {x, Fig. 121 ) into the release fork (z, Fig. 122), fasten it with
both springs (k, Fig. 121 ) and hook return spring (m, Fig. 122) onto release fork.
Place the assembled release fork in the clutch case (return springs touches the rib
in the case).
Slide the check plate and the round sealing ring onto the supporting shaft with Fi g. 125
clutch lever.
Fill recesses of both supporting shafts with grease (ALVANIA 3) and mount Note:
both shafts. The device for heating the intake air prevents the carburettor from freezing when
Center the release bearing (x, Fig . 121 ) with regard to the spigot shaft and fit shims operating the engine at cold temperatures (winter).
as needed. At warm temperatures (summer) pull off the tube (1 ), so that the engine cannot take
Fit both sleeves (k, Fig. 122) and cover supporting shaft with rubber block. in hot air.

62 63
BOSCH STARTER-GENERATOR INSTRUCTIONS AND WIRING DIAGRAM FOR BOSCH STARTER-
GENERATOR
Removal
The sta rter-generator serves for sta rting the engine and for providing current for
Fig. 126 the electrical system .
Unscrew nut (2).
Remove lock washer, thrust Output :
washe r (1 ), p rofile washer, V-belt
pulley half (3), V-belt, profile a ) as starter app rox. 1 HP (DIN ) at 12 Volt
washers and second V-belt pul- b) as generator 160 Watt at 12 Volt continuous output or
ley half. 240 Watt at 12 Volt for short-time operation
Force the hub off w ith two
screw drivers and remove key. Voltage governing is achieved by control box (F & S part No. 2771 003 000 ; BOSCH
Unscrew both fastening bands Ref. 0190 219 002).
(6) and remove starter-generator Required battery : 12 Volt 18 Ah
with rubber damper.
Unscrew supporting bracket (4)
) When the starter-generator is fittet subsequently to an engine, or when wires are
and V-belt pulley (5). replaced, ensure that these have the correct cross-section (see wi ring diagram ).
Fi g. 126

2,5 mm 2
31

Installation
Tighten V-belt pulley (5. Fig. 126) with 3 hexagon socket head screws M 6 x 14
(KM 37) or M 6 x 15 (KM 48).
Tightening torque 0.9 ... 1.2 kpm (6.5 .. . 8.6 ft lb). 2,5 mm 2
Fasten the supporting bracket (4, Fig . 126) with 2 hexagon head screws M 6 x 15,
lock washers, washers and nuts, as well as with one hexagon head screw M 6 x95
(KM 37) or M 6 x 105 (KM 48) with lock washer to the fan cover.
Place both rubber dampers and starter-generator and fasten with 2 fastening bands To be well
(6, ,Fig. 126).
earthed Starter button
Take care of proper alignment of the V-belt pulleys.
Install key into the armature shaft and f it the hub, short end first.
12V 18Ah
Mount V-belt pulley half and profile washers for achieving the belt tension.
Fig . 127
Fit the V-belt and the V-belt pulley half (3, Fig. 126), profile washers for align ing
both pulleys, and tighten w ith lock washer and n·ut M 14 x 1.5.
2.5 mm 2 0.003875 sq m.
Tightening torque 3.5 . .. 5.0 kpm (25.6 .. . 37ft lb). 6.0 mm 2 0.00930 sq m.
16.0 mm 2 0.02480 sq m.
Note :
For t ightening the nut (2), the V-bet pulley (5, Fig. 126) must be turned, to prevent
pinching the V-belt.
Check the pulley alignment and the V-belt ten sion (belt should have a " give" of
approximately 10 ... 20 mm = 0.39 ... 0.79 in. under thumb pressure) and adjust
when necessary.

64 65
 Note:
TEST RUNNING THE ENGINE AND RUNNING-IN PERIOD
By adju~ting the governor spri.ngs (effected by screwing the adjusting nuts in or out),
the eng me speed. can be vaned by about 200 . .. 250 1/ min. By this means it can
Test run always be estab!1shed for what speed the governor has ben equipped. (See chart
Start the engine and let it warm up (as soon as the engine has started, open the for governor .spnngs on page 55). An important requirement is that the two adjust-.
choke). m~ nuts (2, F1~. 96) are. screw~d in or out by an ~qual number of turns, as other-
Wise .the centnfugal we1ghts will not move out uniformly, thus impairing a reliable
On engines with governor, it will be necessary to adjust not only the idling speed, funct1on of the governor.
but also the maximum speed.
Start the engine and check the speed again. If necessary repeat the above proce-
Speed adjustments must always be carried out when the engine is warm . dure ·until the required speed is attained . '
If the on-load speed of the engine fluctuates, although the governor is correctly set
Note: an? the gov~rn<?r parts and t~e throttle valve are easily moving, slacken nut and
A low idling speed is absolutely essential for all engines fitted with a centri- adJust the adJustmg screw (3, F1g . 95) until the engine runs quietly and smoothly.
fugal clutch. The centrifugal weights are only completely clear of the clutch housing Lock the adjusting screw again with the nut.
when the engine is idling slowly, thus avoiding undue overheating and premature
wear of the clutch. yYhen r. p.m . fluctuations cannot be corrected with the adjusting screw the cause
IS to be sought either in general engine troubles or worn parts. '
Idling speed adjustment.
If the enige . is removed from its machinery, the speed is to be set for the engine
Close the control lever or throttle lever, set the requ ired idling speed by meons of the operatmg Without load, according to the chart on page 55.
idle adjustment screw and cerrrect smooth running of the engine with the idle air
adjusting screw. It .is important that no over-revving occurs while adjusting the operating speed, as
th1s may result m damage to the beanngs and a loss of efficiency accompanied by
On cable controlled carburettors, the outer casing of the cable must have a play starting difficulties.
of 1 . .. 2 mm (0.039 .. . 0.079 in. ).
A well adjusted, lowest possible idling speed helps to save fuel, especially when Running-in period
the engine is operated under widely varying load. Even the mos! finely machined surfaces of the rotor 's sealing elements, side plates
and rotor casm.g are rougher than parts that have been rubbing against each other
for . a long penod of t1me, therefore the moving parts must undergo a running-in
Maximum speed adjustment. penod.
(on engines with top speed limit-
ing device) There i~ no need however, to be overcautious. The engine should not be driven to
1ts max1mum speed for the first 5 hours, but should be driven at half-throttle in the
Fig. 128 middle .rpm range. It is i.mportant that no unnecessary rpm are obtained, as this can
Open throttle lever or control result 1n beanng damage and a loss of efficiency accompanied with starting
lever completely and check the difficulties.
engine speed with a revolution It is .n.ot nece~sary to use .an extra mixing proporting of fuel and oil or to use special
counter (repair tool No. 14). If add1tlves dunng the runnmg-in period.
the required speed is not obtain-
ed, or if it is exceeded, it can be
adjusted, while the engine keeps
running, by turning the air vane
pivot (r, Fig . 46).
By turning clockwise the return
spring is relaxed and the speed
))
Fi g. 128 drops, by turning anti -clockwise,
the speed is increased.

Maximum speed adjustment.

(on engines with precision governor)
Open throttle lever or control lever completely and check the engine speed with a
revolution counter (repair tool No . 14). If the required spee.d is not attained or
exceeded, stop the engine and remove the screw plug on the governor housing .
Through the apertu re, the adjust ing nuts (2, Fig . 96) can be screwed in or out w ith
the adjusting sleeve (3, Fig. 96).
By turning them clockwise, the speed increases ; by turning them anti-clockwise, the
speed decreases.

66 67
INSTALLING OR MOUNTING THE ENGINE EFFECTS OF LOCATION ON ENGINE PERFORMANCE
Performance data are based on an intake air temperature of + 20 ° Centigrades
The SACHS KM 37 and KM 48 engines can be used for a wide variety of purposes, 68 ° F), relative air humidity of 60% and an altitude of about 300 m (1000 ft. ) above
such as dr iving generating sets, pumps, boats etc. The conditions of installation sea level. Any devia.tion from the above value~ wil_l affect ~he engine performance and
applicable for each cumbustion engine will have been fulfilled by the manufacturer, the carburettor settmg . In cases where an engme ts used tn a warm or humid climate
if you obtained an equipment with the built-in eng ine. In cases where a. SACHS or at a high altitude, the following rules can be used as a rough guide for estimating
KM 37 or KM 48 engine is to be used for a special purpose, it is essential that the the effect on the power output of the engine :
following points be observed when installing or mounting the engine.
1. For every 100m (330 ft. ) above the reference of 300m (1000 ft.) the
l. The cooling air drawn in by the fan must be able to flow freely away from the output will be reduced by about 1.4% .
engine, especially if the engine is installed under a protective cowling or bonnet.
The cowling should always allow fresh air to enter, and hot air to escape, in 2. For every 10 % increase in the intake air temperature above 20 ° Centigrades
sufficient quantities, or else the engine will not be cooled properly. (68 ° F) the output will be reduced by about 4 Ofo.
2. The engine in its finally installed position must not, even temporarily, be tilted at 3. With extremely high humidity (90-100%), a further reduction in output of
on angle of more than 30 ° . If this angle is exceeded, fuel consumption will be 1.5-2 % will occur for every 10 ° increase in the intake air temperature above
adversely affected . 20 ° Centigrades (68 ° F).
3. All lubrication points of the engine such as gearbox, starter, governor and go-
Example:
vernor linkage must be exposed for servicing.
4. To prevent dirt being depos ited on and in the engine, the air drawn in by the air Engine operating at altitude of 1200 m (4000 ft. ), air temperature + 30 ° Centigrades
cleaner and fan should be taken from a dust-free zone. In the case of agricultural (86° F), relative air humidity 95%.
machinery, the engine should, moreover, be protected by suitable mudguards The performance drop will then be:
from dirt thrown up by the wheels of the vehicle. Although the engine is not
affected by atmospheric conditions, a cover to protect it from rain should be 1. Difference in altitude (1200 m) 12 X 1.4 % = 16.8 %
provided, as this will help to keep the engine in good running order. 2. Difference in air temperature (30 ° C- 20 ° C = 10 o C) 1 x4 % = 4.0 %
3. Increased air humidity (95 % at 30 ° C) 1 x2 % = 2.0 %
5. If the engine is installed in an enclosed space, the exhaust should be discharged
into the open air through a pipe of not less than 1.575 in . (40 mm ) internal dia- 22.8 %
meter and free from sharp bends. A condensation trap must be installed when Hence the total drop in power output will be about 23.0 % , i.e., the original output
using long exhaust lines that prohibit condensation from flowing back into the
muffler. The room in which the engine is located must also be ventilated to of the KM 37 of 3.45 h.p. will be reduced to 2.66 h.p. at 3000 11m in.
prevent condensation from forming in the engine, leading to unpleasant results. 5.50 h.p. will be reduced to 4.20 h.p. at 4900 1l min.
6. If the engine is fitted with a recoil starter, or a starter pulley, sufficient space
should be provided for operating the starter.
I of the KM 48 of 5.50
8.00
h.p.
h.p.
will
will
be
be
reduced
reduced
to
to
3.90
6.20
h.p.
h.p.
at 3000
at 5000
11mm .
11m in.
7. Furthermore, it is important to see that the engine be securely flange-mounted or
that the pedestal stands on a hard, firm base. The strength of the installation LAYING-UP THE ENGINE
mounting should be such as to prevent any distortion between the engine and the
mechanism it drives. The engine shaft and the shaft of the driven machinery If the engine is laid-up for some considerable length of time, there arises danger of
should, when coupled directly, be perfectly aligned. The frame of the machinery rust. For such cases we provide the following instructions for preserving the engine:
should be supported at the foundation by rubber damping pads. 1. Unscrew the muffler.
Then , b'>:' means of an oil ~yringe, squirt 10 cc (0.352 fl oz) of SAE 30 oil (e . g.
8. Strong engine vibration, mainly at the fuel tank, disturb the flow of fuel. The ENSIS-otl 30 of SHELL), whtle cranktng the engine 5 . . . 6 times, into the exhaust
vibrating tank causes the fuel to foam and the air bubbles are fed through the port.
fuel line. When it is impossible to prevent the engine or machinery from vibrating , The sliding course of the rotor housing, the bearings and the rotor are thus
preventive measure should be taken to assure that the tank is free from vibration. s·ufficiently protected against corrosion.
2. To protect .the o_utside of the engine, and possibly the equipment, we recommend
antt-corroston otis of well-known oil companies, such as :
Anticorit 5 of Messrs. FUCHS D-6800 Mannheim , Germany
Lubrication -Oil MIL-L-644 B of MOBIL-OIL
Shell ENSIS Fluid 260 of SHELL
RUST BAN 395 of ESSO
Attention!
If the engine is laid-up for some considerable length of time with fuel in the tank,
segregation of the oil I petrol mixture may occur. In such cases we strongly recom-
mend, before starting the eng ine aga in, to mix the oil I petrol mixture anew by
stirring or shaking, or to replace it.
Resinificated (gummed) fuel feed and carburettor systems as well as damages by
oxidation (rust) inside and/ or outside of the engine are not covered by our warranty.
68 69
lJBRICATING AND SERVICING CHART LUBRICATING AND SERVICING CHART
•int of servicing
· lubricating Lubricant and quantity or servicing operations Lubr icant and quantity or servicing operations

Wet air cleaner Precision speed governor

Pull off filter cap. Remove the cover (e) and replenish with engine oil SAE 40
As soon as dust deposit appears on filter element (n). up to the edge (a).
remove it, wash it in petrol, dip it in e ngine oil SAE 30 or When operating the engine during winter, replace the
40 and let excess oil drip away. engine oil SAE 40 by SAE 10.
Initial filling: 15 cm3 (0.5 fl oz)
Replenishment: up to the edge (a)

Micronic air filter Fuel strainer :

Screw off filter cap. Empty fuel tank.
Replace the Micronic filter (o) is very dirty; if only slightly The fue l filter is directly fitted to the fuel lap. To clean
dirty blow the fi lter element with caution or tap it slightly the former, screw off tap from fuel tank, rinse filter (i)
an a soft surface in order to remove dust deposit. thoroughly in fuel.
If necessary, rinse out lank.
Fit the fuel tap back to the tank and fill the lank .

Spark plug
A quick cleaning of the spark plug from carbon deposit can Ignition system Check the contact breaker and adjust if necessary.
be made ot the insulator and between the electrodes. A cor-
rect cleaning can only be achieved with a sand blower.
Checking
Apply BOSCH Ft 1 v 4 special grease to the lubricating felt
Remove the spark p lu g. Connect it to the ignition cable, pad for the con tact breaker cam.
hold the plug thread in contact wi th earth and work the
starter. If the plug is in perfect condi tio n, a strong spa rk
mus t appear at the electrodes. G ap at the electrodes 0.5
mm (0.02 in .). See arrow. Decarbonizing
(see page 26)
Check the exhaust port and the spark plug hole for carbon
deposit and clean if necessary.
I
Single stage and two-stage gearbox
Blower After heavy dirt deposit on the cooling-air inlet and on the
Oil check cooling fins, clean with compressed air.
Screw out oil level check plug (2) . If the oil level in the
gearbox is lower than the bottom edge of the oi l check
hole, screw ou t the oi l filler plug (1) and pour in as much Carburettor Clea n and adjust.
SAC HS gear oil SEA 80 until oil is coming out of the oil
check hole. Screw the p lugs in again.

Recoil starter Lightly lubricate spiral spring and bearing bolt with Anti-
Oil change
Screw aut the oi l drain plug (3). Drain the oil and close the
)) corit 5.

oil drain hole again. Fill in

100 cc = 3.5 fl oz ~for single stage gearbox) Oil seals Fill with grease (A LVANIA 3)
200 cc = 7.0 fl oz for two-stage gearbox)
300 cc = 10.6 fl oz two-stage gearbox; horizontal version)
of SACHS gear oil (F & S Part-No. 0263 015 005) or SAE 80,
as outlined under ·oil check· . Rotor sliding surface, These are lubricated by two-stroke mixture, SACHS special
e ccentric shaft bearing s oil for Wankel engines (cans of 250 cc = 0.5 liqu. pt., pre-
mixed, F & S part number 2769 008 000) mixed with branded
petrol at a ratio of 1 :50.
Note :
Top speed limiting device
Instead of SACHS special oi l for Wankel engines, the oils
Clean the lever of the bearing bolt (x) and lubricate it li sted in the chart on page 72 an also be used .
slightly.

70 71
APPROPRIATE LUBRICATING OILS FOR SACHS-WANKEL ENGINES TIGHTENING TORQUES FOR BOLTS AND NUTS

All branded oils listed in this chart, preferably special SACHS oil for Wankel Bolts
engines, F & S part number 2769 008 000, or all Super outboard engine oils (with
synthetic components). F & S No. Used for component Size Tightening torques
\Number
kpm I ft. lb.

-o
V)

c: 1940114 002 3 Bearing cover M6 x 25 1.1 ... 1.3 8.0 ... 9.4
-
a
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a c: 0240106100 3 Armature ba se· plate M4 x 14 0.2 ... 0.3 1.4 . .. 2.1
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u.. u.. E z 4: :::1 2740 003 001 3 Fan housing M6 x 30 1.2 ... 1.3
IXl (/')
8.6 ... 9.4
0240104 002 6 Fla nged shaft M 6 x 14 1.2 ... 1.3 8.6 ... 9.4
AGIP-F 1-MARINEMIX
I I IX I I I I I I 1940134 002 6 Intermedi ate flang e M6 x 20 1.2 ... 1.3 8.6 ... 9.4
BP Super Outboard Motor-Oil 0240104002 3 V-belt pulley M6 x 14 0.9 ... 1.2 6.5 ... 8.7
\x xlxlxlx xlxlxlxlxlx l x (magneto side)
CAL TEX Outboard-Motor-Oil 1815 008 000 6 Pressu re plate M6 x 18 0.8 ... 1.1 5.8 ... 8.0
lx I I I I I I I I I
ESSOLUB HD 30 X X xlx l xlx l x l x l xlx x
I Nuts
ESS0-0 utboa rd- Extra-Motor -0 iI
I I IXI I I I I I I I F & S No. !Nu mbe r Used for component Size
Ti g hte ning torq ues

EVINRUDE 50 to 1 SAE 40
I kpm
I ft. lb .

I I I I I I I I IXI 2742 001101 1 Eccentric shaft M20x 1 7.5 ... 8.0 54.4 . . . 58.0
MOBILMIX TT {power take-off side)
X IX IX IX IX I XIX X I X I XI X
I 0942 072100 1 Eccentric shaft M20x1 4.3 ... 4.5 31.2 .. . 32.6
{magneto side)
MOBILOIL TT
I X IXIXIXIXIXIXIXIXIXIX 0316 057 003 18 End covers M6 0.7 ... 0.9 5.1 .. . 6.5
I
SHELL-Oil (1763) 0236 PAE 4884 0316 057 003 7 Fan cover- M6 1.0 ... 1.2 7.2 ... 8.7
I I IXI I I I I I I I housing cover
SHELL-PREMIUM Outboard 0942 020100 1 Pinion M 14 X 1.5 5.4 ... 5.6 39.?. . .. 40.6
Motor-Oil lx I I I I I I I I I I 0942 020100 1 Clutch plate M 14 x 1.5 5.4 ... 5.6 39.2 . . . 40.6
SHELL-Rotella SAE 30 xjx\xlxlx l xlxlxlx l x l x 0942 020 100 1 Centrifugal clutch M 14 X 1.5 7.5 . .. 8.0 54.2 ... 57.8
I
VALVOLINE-Super Outboard
Motor-Oil lx I I I I I I I I I I

72 73
ENGINE TROUBLES APPENDIX

The following is a list of possible engine troubles which may occur. Housing cover for evacuation of air; execution for Messrs. ROTO-
MARIN and SKICRAFT.
A. Engine will not start Engine does not get suitable explosive
mixture because Fig. 129
There is no ignition spark because
1. Water in carburettor,
1. Spark plug is oiled-up, wet, Disassembly and re -assembly is
bridged or damaged, 2. False air infiltrating through loose the same as for the basic engine.
carburettor.
2. Spark plug is wet (outside), The following hexagon head
3. Ignition cable loose or fractured, screws are required for the
B. Drop in engine power housing cover :
4. Contact-breaker points oiled-up,
wet or burnt, because of dirt 4 hexagon head screws M 6 x 38
5. Short-circuit switch jammed, l . Air cleaner clogged with dirt, l hexagon head screw M 6 x 65
(KM37)
6. Ignition armature or condenser 2. Fuel tank gets no air (filler cap).
5 hexagon head screws M 6 x 70
defective. (KM 48)
Engine has been subjected to over- and washers.
Engine does not get any fuel because speed
Tightening torque 1.0 ... 1.2 kpm
1. Fuel tank empty, Overspeeding must be avoided even (7.2 ... 8.7 ft Ib).
2. Fuel tap is closed, for short periods.
3. Strainer in fuel tap clogged with
dirt, C. Other engine troubles
4. Jet clogged. Engine vibrates badly, because
l. Fan wheel wrongly fitted (see
page 40).

STARTER TROUBLES

When defects arise it should be borne in mind that the cause of these defects need
not necessarily lie w ith the starter itself, nor in an insufficient electrical connection
of the vehicle earthing points, but also in the fuel supply. The following remedial
hints are limited to the starter system itself.

A. When the ignition is switched on, B. When the ignition is switched on,
the armature shaft does not rotate: the starter armature rotates,
but the engine does not start:
l. Battery exhausted,
2. Batterie defective, 1. Battery insufficiently charged,
3. Battery terminals loose, oxyd ized, 2. Pressu re of carbon brushes insuf-
earth connection insufficient, ficient,
4. Starter terminals or brushes have 3. Loss of current in the leads is too
ground contact, high,
5. Carbon br-ushes of the starter do not 4. Insufficient V-belt tension (on
lie on the commutator, are jammed engines with starter-generator only.
in their ·g uides, are worn, broken,
oily or dirty
6. Starter switch damaged (pa rts loose ),
7. Loss of current in leads is too high,
leads damaged, lead connections
loose.
74 75