Rotax 912-UL Operating instructions

ROTAK. R s"gl
ftf;rr
hffi&n tal
Eng-frmety'pe S12 G
UL
Edition: 07L992
recommended
BOMBARDIER.ROTAX
GMBH
MOTORENFABRIK
A-4623
GUNSKIRCHEN
_ AUSTRIA
Telefon
:..43-
(O\7
246
-27
1
-0'.
Telefax'.
..
431017
246-37O
Telex:
25546brgk
a, Telegi,:
BombrotaxGrinskirchen
ATS420,--
us
$ 40,-- parl
no.:899072
part
no.:899077
(with
ringmap)

Thble
ofcontents
1) In1roduction....................o...............o.o...........................................................5
1.1) Enginenumber
1.2) General notes
Description
ofdesign,
5.2) Water accumulator
5.9) Cylinder
head...........................
5.10)
Cylinder,
piston
5.11)
Hydraulicvalve
tappet
5.12)
Crankcase
5.13)
Cleaning
2)
3)
4)
s)
6.2) Crankcase and
journal.
bearings
L7
l8
19
20
2T
22
22
23
23
23
24
24
25
25
6) Inspection and
judgement
ofcomponents and
units...............................20
Evaluation
of wearlimits,clearances
and
tolerances
6.1) Crankshaftass'y.......
6.2.1)
Measuring
ofcrankcase
.............
6.2.2)
Thrustringhalves
6.3) Camshaft .................
6.3.1)
Hydraulicvalve
tappets
6.4) Piston
6.4.1)
Pistonrings.........
6.4.2)
Dimension
data
ofpiston
and
piston
rings.........
6.4.3)
Piston
pin............
6.fl Cylinder

6.6) Cylinderhead... ..................26
6.7) Assembly ofcylinder
head
6.8) Overrunningclutch .....................30
1n
6.9) Ignition cover ...-..............31
6.10)
Removal
of
water
pump .-.................31
6.11)
Fitting
ofrotary
sealand
installation
of
water
pump ......32
6.12)Water
pump
housing
6.13)
Driveformechanicalrev
counter ....-.............34
6.14)Magnetohousing............. -..-.............34
6.15)
Reduction
gearbox........... ...-............34
6.15.1)
Checkingoftheslippingtorque .............35
6.15.2)Dis-assembly
ofgearbox .....35
6.15.3)Dis-assembly
ofoverloadclutch ............37
6.15.4)Re-assembly
ofoverload
clutch ............38
6.15.5)Re-assembly
of
gearbox............... .........38
6.16)
Dis-assembly
ofoilpump.............. .....................40
6.16.1)Oilcircuit ..........41
6.t6.2)Venting
ofthe
lubrication
system ..........41
6.17)
Drive
ofvacuum
pump... ...................42
6.18)
Ignition
unit....
6.19)Generator
6.19.1. 47
6.20)
Check-circuit
for rectifier-regu1ator............... ....,....,,.,,.....47
6.20.1)
DC
output ..........47
6.20.2)
Circuitwith
main
switchatbattery ........48
ultwltnmarns

6.21)
Instruments ......51
6.22)Electricstarter
7.4) Assembly
andfitting ofove
7.5) Reduction
gear
for electricrrunningclutch
starter 56
7.6) Ignitioncover -..............57
7.7\ Electric
starter ..................57
7.8) Watcrpump
housing ........57
7.9) Flywheel
7.14)Carb
flange
ass'y.........
7.15)
BING constantdepression
carburetortype64.3......... 61
7.15.1)
Description
ofcarburetor.......... ..............61
7.15.2)
Attachment
............... ............61
i 7.15.3)
Fuel
supplycontrol...... .........61
7.15.4>
Mainregulating
systemwith
pressure
control .........63
7.15.5)
Idling
system ......66
7.15.6)
Staningcarburator
(choke) ...................67
7.16)
Carburetor
actuation .......68
7.16.1)
Pneumatic
synchronization
........ ............68
7.16.2)
Mechanical
synchronization....... ............68
7.17)Actuatingofstartingcarburetor............... ........68
8) Tighteningtorquespecificationfor boltsand
nuts....................r.,.,.........70
9) Tableofwear
limits............... ......................................................7L
10)
11) Dimensionsheets..r............................. 74
11.1)Dimension
sheet
l, crankshaft.........
11.2)
Dimension
sheet
2,
crankcase...
11.3)
Dimensionsheet3,cylinder and piston
11.4)
Dimension
sheet
4,valve
train.........
74
77
75
76
13) Distribution-andservice
partners
for Rotax
engines.............................79

1) Introducti6n
Thismanual
coverstheROTAX4-sroke-,4 cylinderaircraftengine912. The
manual
has
been
prepared
asa guideto helpyou to service
andrepairtheROTAX engine912 conectly.It is
supplemented
bythe corresponding
operator's
manualandacurrent
spare
parts
list.
Forinstallingengineinto
aircraft,consult
the
installationinstnrctions
available.
Inthe
eventofquestions
or
problems,please,
contact
your
local
dealeror
BOMBARDIER-ROTAX,
Austria.
TheRotax
design
incorporates
thelatest
technicaldevelopment.Wereserve
the
right
to
make
modifications
without
priornotice
in the caseof further
developments.
Thismanual
emphasizespaflicularinformation
denotedbythefollowingwordingorsymbols.
A WARNING: Identifies
an
instruction
which,
ifnot
followed,couldcause
personal
injury.
I ATTENTION: Denotes
an instructionwhich, if not followed,could severelydamage
englnecomponents.
I NOTE: Indicates
supplementaryinformationneeded
tofully completeaninstruc-
tion.
Although
the
mere
reading
ofsuch
information
does
not
eliminatethe
hazard,
your
understand-
ingof the
information
will promote itscorrect
use.
1.1) Engine
number
On inquiries
andspare
partorders
always
stateengine
number,
becauseof possible
running
changes.Theenginenumberislocated
oppositeelectric
starteron ignitioncover.
1.2) General notes
Al To wilrantproper
repair,
use
genuine
ROTAXsparesonly. It isnecessary
toutilize
special
tools,
fixtures
andservice
products
(see
chapters3.2and3.3).
AI Repair
worktobecaniedoutbyskilled
persons
only.
Al Useonlyclean
screwsand
nuts
andcheck
face
ofnut andthread
fordamage.
If doubtful"
renew.
f Onceloosened,renew
self-securingnuts.
I Always meet
thespecifiedtighteningtorques
(chapter
8).
I At re-assembly
rcnew
allsealing
rings,
gaskets,
securingrings,
O-ringsandoil seals.

2)
Description
EXECUTION:
ofdesign,technicaldata
DESIGN:
BORE:
STROKE:
DISPLACEMENT:
PERFORMANCE:
MAX. TORQUE:
MAX. A]IOWED SPEED:
CYLINDER:
PISTON:
V4LVE TRAIN:
CYLINDERFIEAD:
COMPRESSION
RATIO:
INLET VALVE:
E)GIAUSTVALVE:
VALVE CLEARANCE:
CAMSHAFT:
NOMINAL VALVE TIMING
(at
I mmvalve lift):
CRANKSHAFT:
COOLINGSYSTEM:
LUBRICATIONSYSTEM:
OIL CAPACITY:
38.912.0101
model1988
31.912.0101withoutoverloadclutch,
model1991
31.912.0111
with
overloadclutch,model
1991
3l.9l2.Ol3l withoverloadclutch,
vacuum
pump,
mod.1991
4-stroke-,
4-cylinder-,horizontally
opposedspark
ignition
engine,onecentralcamshaft,
push
rods,
OHV
79,5
mm
(3,13
in.)
61
mm
(2,4in.)
1211
cm3
(73,9
cu.in.)
c.59
kW (80
hp)
at5500
r.p.ffi.,
performance
sheetLb.365
c.103Nm(60 ft.lb.)at4800r.p.rr.,
perform.
sheet
Lb.365
5800
r.p.m.
light
alloy,MKASIL coating
cast,light-alloy
piston,
3
piston
rings
OHV,hydraulic
tappets,
push
rods
androcker
arms
4singlecylinderheads
9:1
38
mm
(1,5
in.)
32
mm(1,26
in.)NIMOMC, armourwelding
atseat
automaticcompensation
byhydraulic tappet
steel,annealed,
nitro-carburized
inlet
opens:
at
T.D.C. exhaustopens: 47"8.B.D.C.
inlet
closes:
47oA.B.D.C exhaustcloses:
at
T.D.C.
supportedin 5joumalbearings
liquid-cooled
cylinder
heads,ramaircooledcylinders.
Oil
cooler
in airstream
drysump
forced
lubricationbyoil pump driven
fromcam-
shaft,
oil return byblow-by
gases
3litre(.793
gal
US)

\---l' t
OILQUALITYS
OILPRESSI,]RE:
OILDELI\IERYRATE:
IGNTilONUNIT:
GENERATOROUTPUT:
RECTIFIER.REG}I,JI.ATOR:
IGNITIONTIMING:
SPARK
PLUG:
ELECTRODE
GAP:
MDffURE PREPARATION:
AIRINTAI(EFILTER:
FI,JEL
PUMP:
FUEL:
FI,JEL
CONSI,JMPTION:
STARTER:
REDUCTION
GEAR:
REDUCTIONRATIO:
OVERLOAD
CLUTCTI:
TBO(time
bcfore
overhaul):
DIRECTIONOFROTATION:
ENGINE
CI.JRBWEIGHT:
high
performance
automotiveoilAPI
"SF"
or
"SG",
e.g.SAE
15W40, secOperato/s
Manual
approx.3,5bar(50p.s.i.)at
5500r.p.m.and
110
oC
(230
oF)
oil temperature
16
Vmin
(4,23
gal
US)
at
5500r.p.m.
dualignition
ofbrreakerless, capacitordischargedesign,inter-
fercnce
suppressionand
integrated
generator
AC,12V250W
13,5
to14,2 V,DC.
atstart6oB.T.D.C.,atoperation
260B.T.D.C.
srze
12
mm
(.47
in.),
EYQLJEM
AD800 L
0,5
+0,6mm
(.02
- .023
in.)
2xBING
constantdepressioncarburetors
size32,type&
2xmicronicfilter,brandK & N.
mechanical,
diaphragmtype,
Pierburg.
premium,
leaded
orunleaded,min.
RON
95,orAVGASI00II
c.TlS
g/kWh
C45
p/hph)
at3/4load
electric,withovemrnning
clurch
integrated,spur
gear,
withtorsionalshockabsorber
standard2,n3
multi-disk
(option)
atPresent600
h
anti+lockwise,
looking
at
propeller
shaft
c.56
kg
(123
lbs)
with: electric
starte,r,carburetors,oil container,
airfil-
ters, fuel
pump,ignition
unitand
generator
withouc muffler
c.57
kg(126lbs): withoverloadclutch
Exhaust
systcm:
c.4kg
(9lbs)
WEIGHT
OFEQTJIPMENT:

3) Tools andsupplenrentary
means:
3.1) Standard
tools
Followingstandard
Openendspanners:
Screwdriver:
Phillips
screwdriver:
Torquewrench:
Sockets:
Mallet:
Hammer:
Pliers:
Ill. No. Part No.
r-2 877 230
, 2 877240
3 876510
4 877250
5 877252
6 877
254
7 877
270
8 877275
9 877400
10-11 877
375
11 841875
r2-r3 877285
13 941685
14 877320
15
16
L7
18
18
18
19
20
2l
877
290
276280
gLr420
876360
277810
277790
877380
877410
877360
mechanic
toolsare
required:
a/f8,
10,13,14,17
size
4 and7
medium
size
I xsmall
size
fortorque uptoapprox.30
Nm(270 in.lb.)
1xmediumsizefor
torque
upto
200Nm(1770 in.lb.ll47ft.lbs)
size
12,13
to
fit onsmallertorque wrench.
size?4,4l,46 tofit onlarger torque
wrench
socketsize
4t and 46tobeof highshankexecution
Plastic
orwood
c.500
g
(1,1
lb.)
A pairof circlippliers
for circlip size72onrocker armshaft
Description,
application qty
Trestle
ass'y,for
workbench ...........1
Mounting
plate
ass'y .....................1
Insertion
punch
for
oilseal
850977
(12x30x7).................................1
Insertionpunch
forrotaryseal.......... .............1
Insertion
punch
for
timing
gear
......... ..............1
Insertion
punch
forwater
pump
and
rev.
counter .............1
Insertion
punch
for
oilseal850967
(32x52x8).................................
I
Insertion
punch
for
oilseal
230137
(40x52x7).................................1
Insertion
punch
for
rev.
counter..... .................1
Puller
ass'y
forflywheel... .............1
Hex.hd.
screw
Ml6 xl,5xl20 .......................1
Press-on
device,timing
gear
oncrankshaft
......... ............1
Hex.hd.
screw
M16x1,5x60............... ...........1
Press-inringforball
bearing832235
(35-72-17)
usedalongwith
insertion
punch
877
275 ........1
Spanner
insertfor
pump
impeller ...................1
Spark
plug
spanner18
a/f ..............1
Handle
8x130 .............1
Allenkey
5 alf............. .................1
Allenkey
6a/f............. ..................1
Allen
key4a/f............. ..................1
Valve
spring
fitting
jig
............ .......
1
Protection
piece
forcrankshaftend .................1
Protection
sleeve
foroil seal installation
(850
967
,32x52x8)
..........1
Apartfromthese
basictools,
followingservice
tools
and
fixtures
are
needed:
3.2) Special
servicetoolsand
fixtures:
Thefollowingtoolsandfixtures
are
listedin the spare
parts
list,
too:

22-23
22
23
877016
877011
877021
876950
8773t5
877zffi
877300
876978
877390
24
25
26
27
28
29
Circlipinstallationtoolforpiston
pin
circlip ....................1
Circlipinstalllation
pusher,piston
pin
circlip ....................1
Circlip
installationsleeve,
piston
pin
circlip ....................1
Dial
gauge ...................1
Sraightedge
tocheck
protnrsion
of
journal
bearing
half
.......... .............1
Cylinderaligningtool.......... ........1
Alignment
plate
for
joumal
bearings........... ....................1
Pistonring
clamp
for
piston
79,5
.......... ..........1
Pin-face
wrench
for
adjustingoverload
clutch ...............1
oooo
26
'.8
12
o
t3
bl
I
I
7
6
5
4
I20
I21
18
17
16

30
31
32
33
34
35
36
37
4) Powerplant in aircraft
3.3) Lubricants,
securing
agents,
sealingcompound
297
7lO PU-glue,forabsorptionofvibration ..310ml
237433 MOLYKOTE
G-N,lubricant............ 100
gt
897
330 Lithiumbase
grease,
toprevent leakagecurrent .250 St
899788 LOCTITE
648,
green ........
5 gr
899
785 LOCTffE Z2l,violetlowstrengthbond 10ccm
899784 LOCTITE
5'l4,orangesealingcompound ............50
ccm
29743I LOCTITEAnti-Seize,
toprevent frettingcorrosion 10 gr
996940 Gasketset
.................:............ ...............I
37
ENCINE
Gesket
sct
f.tml
4.1) Removal
ofengine fromaircraft
Priortoremoval
of enginefromtheaircraft,carryoutthe
following:
- Cool
downengine
first.
- Disconnect
battery.
- Drain
cooling
system.
Sincecoolantisnot
just
plain
water
butantifreezeconcentrate,
store
forre-use.
- Remove
carburetorfromintake
manifold.
Blockfuellinefromtank
topump
(close
fueltap).
Pulloff fuelhosefrompump
inlet.
- Severoilcircuitbydisconnecting
oillinefrom
tanktooil
pump
and
return
linefrom
engine
tooil tank.
- Drainmotor
oil.
- Disconnect
pick-up
cables
forignition
circuitA and B and forrev.-counter.
- Disconnect
pick-up
cablesfor hour-meter,
temperatureand
pressure
indication.
- Disconnect
theeighthighvoltage
leadsfrom
the
spark
plugs.
- Remove
exhaust
system.
- Removeany
obstnrctionslikecovers
anddivisions,air
guides
etc.
f REMEMBER! Severwireoneverywire-secured
boltbefore
removal.

I ATTENTION: Priorof detaching
anywiring,mark
connection
toensure
correctre-
assembly.
Decide
whether
toleave
thesubframe
of engine
suspension
fittedtobulkhead
ortoremove
engine
alongwithsuspension.
Normally,
with all connections
toenginesevered,
theRFI suppression
boxand
carbswill
remain
in the
aircraft.
Afterlifting theengine
outofthe
aircraft,remove
theright,lower
coolanthose
andthan
attach
the
engine
at
its
right
crankcasehalf(cast
mark
"re")
totheassigned
tresrle
(877
230)
fitted
on
your
bench,
utilizing
two
M10screws.Ensure
min.20
mm(.79
in.)
thread
engagement.
t NOTE: when
removing
coolanthosefrom
thealuminium
inlet
elbow,
don't
use
a
screwdriver
orany
othersharp
toolforreason
of possible
damage.
4.2) Re-installation
ofengine
intoaircraft
Generallyinverse
rcmoval
procedures.
However,pay
attention
tothefollowing:
- Afterfining carbs,
check
function
and
easymovement.
- Checkfunction
ofthrottle
and
star:tingcarbcables.
- Carry
outuniform primary
setting
of carburetor.
Turnback
idleadjustment
stop
screw
toclose throttle
valve
andfurther
toclear
0,1mm
(.00a
in.)feeler gauge,
and
then
open
throttle
byturningin screw1,5
turns.
- Connect
pick-up
cables
toelectronicboxaccording
towiringdiagram.
- Connect
the
8highvoltageleads
according
towiringdiagram
andscheme
oncover
of
interference
suppression
boxtospark
plugs.
- Checkrouting
offuellines.
- Checkoil- and
coolantlevel.
Replenish
as
required.
I ATTENTION:Ensure
thatallthe
suspensionscrews
are
tightened
andwire-secured
where
applicable.Don't
connectbanery
before
alltheinstallation
iscomplete
and
ensureignition
switch
isin "OFF" position.

5) Dis-assembly ofengine
Anach
enginetotrestle,drain
any
remaining
oilfrom
engineand
gearbox.
If fitted,remove
vacuum
pump.
5.1) Intake manifold:
Remove
the
4Allen
hd.screws
M6Oandtakeoffintakemanifolds
@alongwithO-rings
and
pressure
equalizing
tube
0. Slacken
clamps
25/12
()oncoolanthose
@between
accumulator
@and80"bends.O = crankcase plug screwof tapped
holefor crankshaftlockscrew

5.2) Coolantaccumulator:
Slackenouterclamps23112
andwittr-
draw
coolantaccumulatoralongwith
hoses.
Remove
crankcase
plug
screw.
Tum crankshaft,
using
ring spanner
24
a/f,
into
T.D.C.
position
on
cylin-
der I and2 and lock crankshaftby
fininglock
screw241'965instead
of
plug
screw.
To facilitate
positioning
of crank-
shaft,turn crankshaft
until align-
ment
ofthe
forged
four-digitnumber
Oonflywheel
g with
theedge0 of
ignition
cover
isgiven.
To ensureproper engagementof locking
screw in crankshaft,turn crankshaftback
andforth till engagedandttrentightenlock
scrcwtoapprcx.l0 Nm (90in.lb.).
5.3) Water
pump
housing:
With enginefined to trestle,turn
unitsothatmagneto
endshowsup-
wards.
Loosen
8clamps23112
and
pull
off
the
4
coolant
hoses
fromwater
pump
Oandcylinderheads.Remove
both
Allenscrews
OM6x50 andtakeoff
waterinlet
manifold
0 alongwith
O-ring. Three additional Allen
screws
M6 O have
toberemoved
before
waterpump
housingand
gas-
ketcanbetakenoff.

5.4)Flywheel
Remove hex. hd. screw
Ml6xl,5 frommagneto
endof
crankshaftusingsocket
24 alt
and
pull off flywheel
utilizing
pullerass'y
877375
andprotec-
tion
piece
877
410.
I ATTENTION: Remove
Woodruff
key prior to
removalof
lgnruon
coveras
preventive
measure
against
damageofoil sealand
journal
bearing.
5.5)Ignition coverassfy
Removeseven
M6 AllenscrewsandthetwonutsM5 onelectricstarter
studs.
If need
be,
removeelectricstarterafter
detachingclampO.A blow
witha mallet
will separateignition
cover@
fromcrankcase.Take
off ignition coverand
remove
O-ring
fromoil duct.
Rm,,,912-UL

5.6) Overriinninggear
ass'y
Withdraw intermediategear shaft@and
removeinterrnediate
gear
O andthethrustwashers
O 12,5121,5/1 oneithersideof the
gear.
Use
socket
46 alt
(highshank)toremove
hex.nut
()
M34x I5 from crankshaft.
I NOTE: Hex.nutO hasleft hand
thread!
Placeprotectionpiece8TT4I0oncrankshaftandpulloffoverunningclutch
housing@,usingpuller
877375.The
following
items,
i.e.
freewheeling
gearO
andtiming
gear26T.
placed
behind,the
worrn
gear
Oand
pumpgear
@
pressed
to
camshaftaswellas
timing
gear
52T.Ocanberemoved
onlyafterspliningofcrankcase.
5.7) Oilpump:
With engine
finedtotrestle,turnunitso
thatprop
gear
showsupwards.
Remove
oil
filter O usinggrip-band
spanner.Undo
fourAllenscrews M6x45
@andtakeoffoil
pump
alongwiththreeO-rings @.
Rnt;:,9.r1:2.U1

5.8) Reduction
gefirbox
Afterremovalof eight
M6 andtwoM8Allenscrews,withdraw
gearbox,
aided
bytwolarge
screwdrivers
O appliedattheassigned
lugs
0.
I ATTENTION: Don't damagebearing-and
oilseal
faceonprop shaft
at withdrawalof
gearbox.
Remove
hex.nutM30x
1
,5
using
socket41a/f,rnd
pull
offdrive
gear
834
I60 fromP.T.O
end
ofcrankshaft.
If need
be,usetwoscrewdrivers.
I NOTE:
Hex.nut
withleft-handthread.
5.9)Cylinder
head:
Turnengine,
fittedtotres-
tle,
withcylinders
1and3
pointing upwards,and
numberthefourcylinders
acconding
toill.4.
Take off valve cover O
and @ along with O-
rings after removal of
oneeach
M6x25 Allen
screw@andwasher.
Removecylinder
headnuts
()
crosswise
and
lift off cylinder
head.
Theoil returntubes to
remain
in thecylinder
head.
l\ {;D
tL_L))l
t ATTENTION: Don'tdamage
sealing
face!
:.::,912-LJ[

Remove
O-rings16x5
fromcrankcase. :q1
I ATTENTION: Nowasher
undercollarnuts.Layasidenumbered
cylinderheads
ino*uy#
nottodamage
scaling
surfaceandoil rcnrrntubes.
Liftoutoil-filledpushrods.
Stopoilfuomdrippingbysealingwithfinger.
Co-ordinatepushrods
withcylinder
toprevent
anymix-up.
I'
5.10)
Cylinders
and
pistons:
T NOTE:
5.11)
Hydraulic
valve
tappets:
Remove
hydraulic
appetOusing
a
pointed
tool9. Don't
engage
atcirclip0.
f AT?ENTION: Lay asidetappersin a
manner
toensurerefit-
tin
g
intheirinitialplace.
Now turn engineon trestleandproceed
withdisassembly
ofcylinder
2and4.
Priortoremoval,
mark
cylinders
and
pistons
toensure
correct
co-ordination
atre-assembly.
Cylinders
areiden-
tical,
pistons
withoffsetcentres
ofpin topiston.
Disengage
srankshaftlockingscrew.
With piston
no.I in T.D.C.,
withdraw
cylinder
no.I carefully,
avoiding
any
damage
to
piston
and
rings.
After moving
circlipsO to9 oblockor 3 oblockposition,
removepistonpincirclips
bysuitable
ground
screwdriver
g.
Push
out
pistonpinusing
guiding
punch
ortool
877090.
Coordi-
nate
piston
pinto
piston.
Same
procedurc
on
piston
and
cylinder
no.3.

5.L2)
Crankcase
I NOTE: At splitting
of ttrecrankcase,
remove
firstthe
9AllenscrewsM6followed
by8Allen
screws
M8and
collarnutM8.
If stillfitted,
i.e.if not
been
usedfor
engine
suspension,remove
studM10
alongwith
distance
sleeves,washers
and
nuts.
Separate
thetwo
crankcase
halves,
if necessary
byapplyingpressure
at
thelugs
O.Lift offleft
crankcase
half
(cast
mark
'LI').and
put
aside.
r ATTENTION: At
dis-assembly
take
care
not
tohit thesealingface
of the
crankcase
byaconrod.
V
fo

Lift otitcamshaft
Oand
putaside.
Removeovemrnnin
Egear
50
T. O and bearingbush
from
crankshaft0.
Carefullyliftcrankshaftoutofcrankcase
andstore
insuitable
place.Remove
and
mark
thesix
journal
bearinghalvesand
the
twothrust
ringhalves.
Removefromcrankcase
prop
shaftroller
bearingOalongwithoil-sealOand
retaining
ring
@.On
engineversionwithvacuum
pump,
remove
drive
gear
O,shaft ass'ywithballbearing
@andoil-seal.
Take
off7O-rings9-2.
I ATTENTION: Forlonger
storage
protect
allparts
againstdustanddirt.
5.13)Cleaning:
Generallycleanall metal
parts,
except
crankshaft,
in gasoline orkerosene. Don't
usecold
cleaning-ordegreasing agents.Remove
remainsofsealantwithsealantstripper.
A WARMNG: Caution,beaware ofvapourswhenhandlingwithgasoline
andsolvents.
Inhalation
ofthese
vapoursisinjurious to
yourhealth.

6) Inspection
and
judgement
ofcomponents
and
units:
Evaluation
of
wear
limits,
crearances
and
torerances
6.1) Crankshaft
Aspreventive
measure
against
foulingof the
con-rod
bearings,
never
wash
acrankshaft,
but
just let drip off oil andwipe with anon_fraying
rag.
Zyt.1
Zyl.2
Dimensions
joumal
ofthe
3main
bearings
O and
O
joumal
arpowcr-rakcoff
end
(pTO)
g
joumal
armagnero
side
(MS)
0
main
bcaring
-radial
clcarance
crankpin-radial
clearance
crankshaft
-radial
clcarance,
magneto
sidc
crankshaft
-radial
clearance,
pTOside
crankshaft
- axial
clearance
crankshaft
- outof round,
pTOand
MS
Zyl.3
Zyl.4
ncw
mm
4445 + 44,46
27,99
+28,ffi
31,99
+32,6
0,A25+ 0,06
0,015+0,050
O,U2
+ 0,04
O,U2
+ 0,04
0,08 + 0,32
0,04
(in)
( + 1,750)
( + rJA2)
( + t,ZSg)
(0,001+ 0,002)
(0,001+ 0,002)
(0,00I
+ 0,002)
(0,001+O,W2)
(0,003
+ 0,013)
( o,ooz;
wear
limit
mm
(in.)
4,40 (1,749)
27,95(1,1cf/)
31,95(1258)
max.
0,12
(0,005)
max.
0,12
(0,m5)
max.
0,12
(0,005)
max.
0,12
(0,m5)
max.
0,50(0,020)
max.
0,06(0,002)