Yamaha Towny MJ50 User manual

8YAMAHA
SERVICE MANUAL
MANUEL DJ\TELIER
5N7-28197-70

Particularly i mpo rta nt in for m at l oo is dis·
ti ngui shed in this ma nual by the following
notations:
NOTE:
A NOTE provides key informa t ion to make
procedures easier or clearer.
~~~~ ~ 3
A CAUTION i nd i cates special procedure s that
m us t be followed to avoid damage to t he
mo t or cy cle .
1'4·
hfr"t'''
A WARNING i nd icates special proce du re s
t
ha t rnust be followed 10 avoid injury to a
mo torc yc le opera t or or person inspecting or
r
ep air ing the mo t orcyc le.
MJ50J
SERVICE MANUAL
FIRST EDITION, APRIL 1981
ALL RI GHTS RESERVED BY
YAMAHA MOTOR COMPANY, LID .
JAPAN
PR I NTED IN JAPAN
Dans cc mJnuel , ks informations par liculicre-
ment i mportantes sont repfr~ par les no l ;J·
tion~ sui\'antt;S:
N .IJ. :
l"n N.B . fournil les informations en rdpport
ave c Je s r~prei; pour rendre l es proc<duresplus
fociles ou plus claires.
:: 1tI~til1~~ ~
Un A lTENTION i ndique les procedures
spt!cia les qui doh•ent t!tre suivies pour Cv itcr
d)endonunagcr la m o1o cycle1te.
AVI
RJISSD I F.N T
Cn AVERTISSEMENT i ndique les procedures
sp<!cia l eS qui dOi \ 'C t lf et re $1. liV'i E:S pour t':\'iter
un acdc.Jen t aJ'u tHJsateur de lti motocyclcttc
OU a la pcrSOJlJlO <OJ1trola11t OU rcparan t Ja
mo1ocyclelte.
~ IJ 50 J
~1.- \ i'IUEL D'ATELI ER
PRE~ ILER£ED I TI01'.A VR IL 1 981
TOUS DROITS RESERVES PA R LA
YA ~ L~HA )!OTO R CQ)IPA1'Y. LTD.
J..\P01'
NJ>RJ.\IE AUJ..\PO :\

CONTENTS
IGNITION CONTROLSYSTEM ...... . ... . ..... .• ....• .. .. ..
A. Basic circuit diagram . . . . . . . . . . . . . . . . . . . . • . . . . . . . . . . . . . . 1
B. Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . • . . • . . . . . . . . . . . 2
C. Engine speed control unit checking. . . . . . . • . • • . • . . . .• . .• . . . 3
11 POWER FLOW DIAGRAM ..... .. .... ..... • . • • .. . . • . . .• . ••. 4
Ill REAB ARM AND REARSUS!'ENSION .. . • . . . . • . . • . . • •• . . . •. 6
A. A ea r arm rernoval . . . . . . . . . . . . . . . . . . . . • . . • . . . . . . . • . . . . . 6
B. Rea r arm installat ion..... . .. . ......... . .. . . ............ 7
(VM ISCELLANEOUS. ... . .... ..... . .. . ......... ............ 8
A. Specifications . . . . . . . . . . . . . • . . . . . . . . . . . .• . . • . . . .. . . . . . 8
B. Cable routing .. . .. . . ..... .. •.. . . ....... . .............. 18
C. Wiring diagram . . . . • . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
CONTENU
SYSTCMl:i DE COMMAND£ D' ALLUMACE ...... .... ... .. . . ..
. ~ . SchC r na du circuit ..................... .. . ........ . ... .
8. F'onct i on n emen l . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . .• . . 2
C. Con tr6 1de l'unj tt de commandc de v it\!SSC du mot e ur . . . . . . . 3
II SCHEMA Dt; PASSAGE DE LA PUlSSA:"CE . ..
.. .. .. ... ... 4
llI BRAS ARRIERE EL LA SUSPENSION ARRIERE .............. 6
A. Dtposc de bras anierc . . . . . . . . . . . . . . . . . . . • • . • • . . . . . . . . . . 6
B. Mon13ge de bras
anicrc . ... ........ ..... .. .. ..
IV DIVERS ... . .
J\, C3rac1cris t iqu es. . . . . . . .... . .... ........ . .. ... .. . .
Jl . Chcmi nel!l<'nt des cables ........ .. • . ...•. ... ..
C. Schema de ca bl ase. .... . . .. .. .• . . ..... •. . • . . ... • .....
13
13
IS

I IGNITION CONTROL SYSTEM
The MJSOJ d istinctly indicates START and
RUN on the main switch. The electric engine
spffd control unot PfeYOnU the motorcycle
from lurching f0<ward due to the roder"s un·
skillf ul operation.
l' ·h1 flMll ___________
1. Nevt:r start the tngine or !et it run for
any 1Cfl91h of time in 1 cf~ area. T he
exhaust fumes arc poiionous and can
cause dea th within 1 short time. Always
operate the motorcycle in en area w ith
adequate venti la tion.
2. Do not run the t:<l!Jina unti l you know
the mo toteycle hH vr10u9h engi ne oil.
A. Basiccircuit diagram
'-
Li9"t.t'lf~
COLO"COOC
2.
,__
...
-
3 Cha...'9teoo•
"
·· -
• ...c.
........
..
'""
..
........,.,,w c eft
o ..
°'-
G. RKtilicr Y , , ... VdJovr
1. Hndl' ttn
8(V , , , • ~.lYtHo " · '
a.
r .u~u
am .... S.u</Rtd
9. & lt !f)'
Vl /S, '.
Wb + l ~IBl.K lc
10. t-Wnt wi: ch
11. '"$l AIU "' in!SCUOf l'l!N
12. ltf'lt
.ond
1J . s,.\..,.
...
C.0.1.•mt
IS . ~J,pMCtc:oeuc'""·c
'·
l
).
'·
t.
'·
10
II .
12.
tl .
.. .
!S ·
I SVSTDlE DE CO~L\IA "llOE D"ALLUMAGE
Le contaclcur acle du mo1Wc MJS OI indique
d1Sti11c1cmcnt START e1 RUN. L'uml~ ~i.,ct
rique Uc commande de \'itc:sst du mol~ur ~-.ire
que la motocycleltc ne bondif'< lors<1ue le
pilo1c l"uldise maladroit•mcnt.
iiji ; il6}1 8 §11HM ____ _ _ _ _
I . ~e jamais demarrcr Ou laisscr tourner le
mutcur d>ns un loc3I fcrrne. Les f;ll.
d\!chappem<r.t wnt IO\lqucs el "'""""t
cntr.rncr l"t!Vl.nousss:emcnt ct 11 mort en
P<!U de temps. TouJOUI"> uu~.er >o trc
motocyclcttc d;ms un enJroit pr~sen t::int
unc v•nti la lion aolequitc.
2. Ne pas faire 1ourner le mottur cant qua:
mus nc suvez pas s"i l3 3$S<% d'hutlc.
A. Scbem3 du rircuit
lot-.cd~lp
COOfCOllLU
9cbti1W(•,..Jtt: ... ...
ao-.r t~ cJur~ JI
RO"C<
ltq\lb_C_.
I trr:olf
eo ... u:n.ct sr.pidotl. o ..
°"-
Rtdr bt.nir y . .bU!"lt
l'hltc S:Y. t\o:.rfhue
F~antf: t f" 8 1R. . . X<\,1/RO•at
8.tC(l'k W/8. • • R...,c{K olo
C011bttte'.'Q ldf
T'->.ot• Jir dftzwr"P'
·-d'.U.JUte
lloush
81o<C.OI
IJndtl:ii~clllleirtk,.dw.otcw

B. Operation
1. WHEN THE KEY IN "START"' .•..•••
THE ENGI NE CAN BE STARTED.
When the ma in switch key is S(lt to
ST ART, the start lndk:ator li ght is turn·
ed on by the battery,
When the kick pedal is kicked, the fly.
wheel magneto turns and the chargecoil
generatC$ a voltage of 150 to 350 volts
which is
stored in the condcOS(lr in the
COi unit. When a tri!l'J@r voltage from
the pulser coil turns on the SCR l
!sili<:oo-controlled rectiller), the elect·
rtc ity sto r ed in th e condenser is discharg·
cd to the primary winding of the i gn iti on
col l. This induces a high voltage surge in
the secondary winding ,,nd produces a
spark across the spark pl ug gap.
2. WHEN THE KICK PEDAL IS KICKED
WITH THE
KEY IN "START" AND
THE THROTTLE GRIP
IS OPENED .. .
THE ENGINE
WILL NOT PICK UP
SPEED AND YOU CAN'T START OFF.
When th e kic,k starter is kicked w ith the
key in "'START" and th e thrott le grip is
opened, the engine speed will increase
slow l y. But before the engine reaches the
speed where the cl utch engages, a trigger
voltage from
the pulser coll tums on the
zener dioke (ZDI which 1urns on SCR2.
As a result, the voltage from the charge
coil is not supplied to t he COi unit; thus
no spark is produc ed al the spark plug.
A• t he engine speed decreases, both ZD
and SCR2 turn off bu t the engine keep s
on running by ut il iz i n~ the CO i circuit .
By alternating the operation specit ied
above, the engine speed is controlled to
2, 300 • JOO r/min.
-2 -
B. fonctionnement
I. QUAND LA CLE !OST SUR LA POSI-
TION START .... LE MOTEUR PEl!T
ETRE DEMARRE.
Qu 311nd I~ de de comac t est sur la posi·
t ion STARl. le tem oin "ST1\RT"' est
allum~ par m< hauerie.
Qu11.rtd la pedale de kick est acrionn~ c . le
\Ohmt m~~tique coume ct tc bo b inage:
~ char:;• ginere une tension de 150 a
350 '"<>Its qui est stocket d•ns le con·
densoteur du bloc COi. Quand Un< teo·
sion de declenchemcnt vonant du
bobinagc d' impul<ions cnclenche kl SCR
(1hyristor). l"clectricit6 stockcc dn 1" le
condcnsateur est dcchargcc d•ns l"en-
r oulc11 1ent pr imaire de la bobine d"ul·
lum:igc. Ced induit unc pointc de haute
tension d:ms l'c:uoulcmen1 sccondaire ec
cntrafnc le j>illissement d' un c ~Linc.<lte
cntn: lcs electrodes de la bougie.
1. QUA'.\'D LA PEDALE DE KICK EST
ACl'IO!'\NEE L.ORSQLll:: LA CLE Of.
CONT,\CT EST SUR LA rosJTJON
START
ET LA POIG'.'<EE D"AC("ELE·
RATION OUVERTE .... LE MOTEUR
:-<E l'REND P ... S 01:: Vll'ESSE ET
VOUS 'llf. POUVJ:2 PAS f'ARTI R.
Quand I< kick est actionnc lorsquc la clc
de
<'On ta ct at sur la po:.iti on START et
b poiin<c d'a<..:<!loration ou«rr~ . la
nh~~ du moteur augmcnte lcnrement.
..\vane que c~ne \i l ~>Se aue igne le re,Pme
d'embrayate. UM r~nsion de d~clenc h e·
mtnl ' cnant du bobinagc d"impulsions
cndcnchc la diode zencr (ZD) qui
cnclencbc le SCR~. Par snitc. la 1•nsion
du bobinage d~ chaii:c n'cst P"" enYOyee
au bloc COi
ct ii n'y a done pas de
iaiUl<sement d'<'tiocdlc cntre l es ~lc e tro ·
des de la bougie. Quand la •itcs.c du
motcur dim inue. la diode z~ncr (ZDJ ct
kl SCR2 sonL dedenches amis le motcur
con tinue de tou m er gr3cc au circuit C.:0 1.
P ar alternance des operations s~cifiees
c i ~des.swt, le regime du motcur est main·
tcnu ~ 2.300 • 300 tr / mn.

3. WHEN THE KEY ISSWITCHED FROM
"START" TO "RUN" .... THE EN·
GINE SPEED CAN
BE INCREASED
AND YOU
CA N START OFF.
When the main switch key is tu rned
from STA
RT to RUN, t he eng ine speed
control
un it \'li ll not function, and the
engine operates through 1he COi circuit.
The engine speed will increase in res·
po n se to the throttle opening so that
you can start off. When t: he main switch
key is turned from R UN to ST ART, th e
engine speed control unit will funct io n
to contro l the en gi ne s;>eed. That is , the
engine is placed under 1hecondition des·
cribed in 2 above.
4. IF THE KICK PEDAL IS KICKED
WITH THE KEY IN "
RUN" •. .. THE
ENG IN E WILL NOT ST ART.
Wh en the kick pedal is l<ic.~ed wi th The
main switch key in RUN. the SCR2 in
the engine speed contr0 I unit wms on,
and the voltage genenrmd by the charge
coil flows through SCR2 to !:l"O'Jnd. This
means that no spar' ~ is p roduced and
thus the e r>~in e · j••il! no t start.
C. Engine speed contro l un it checking
If engine revol ut i on s are not cont rolled at
2,300 • 300 r /m in by means of the engine
control unit:
1. FirSt, check
the coupler for connection.
2. Then, replace the control unit assembly
as required.
- 3-
3. QL'AN I> LA CLE EST ~llSE DE LA
POSITION START A LA POSfflON
Rt.:'.'I .... 1- .\ VITESSE DU MOTE.L'R
PEL' T ETRE AUCMEN TEE ET \'O US
POUVEZ l'ART I R.
Quand la cle de contact est miso de la
position START ~ la p<>sition RUN.
runiti! de co:nmande de v itess~ du
moteur est ino;>er.mte. et le moteur est
commandC par Je drcuit CD I. La "He ss.:
du mot cur ob~ i I aux sollicitations de
l'accelerate1>r e t vou• pou,·cz pu1·tir.
Qu•n~ la ch! de co nt ott est misc de la
po sition Rl:N ~ la pos ition START.
runite d~ commande de. \'ilcs.sc du
moteur
se met en action et rCgu lc la
vitesse du motcur. Autremr.nt dit. Jc
moteur es1 mi s sous la condition d~rhc
en 2. ci· dcssu s.
4. SI LA l'J::O, \ LE D E: KI CK EST
..\CTIOX:>iEE LORSQUJ:: LA CLE DE
CO:\TACT EST SUR
LA l'OSlTION
RL'l\ •.
•. LE ~!OTEUR NI:: DEMARRE
P..\S.
Quand la p;dak de kick est actionm!e
l orsqu~ la clC de ..:onlaa est s ur 1:1 p osi -
tion R UX , le ihyri.to r 1SC R1 d< l'un itt!
de comm.a.ode de ,;re:s.s~ est enclenche ~ ct
la tension gen~ r c< par le oobina8e d•
charge passe du SCR a masse. Ainsi
aucune Ctinoene n'cst produitc ct le
ntotcur ne . pe.ut pa.;; demam:r.
C. ContrO le de t• unifC de co mmand e de
vitesse du rn ot cur
5, le regime du moteur n'e>t pas com m and~~
2.300 =300 U fmn va r !'unite de co11 1mande
de vi{cSSC du ntoieur:
I. En prc}mier lieu. co ntr O! er sil n · : ~ a pas
de mauv ais con la ct au roupleur.
., Ensujte. changer l'c.~nsemble unite de
comm ande si n~«>sai r e.

II POWE R FLOW DIAGRAM
II SC H EMA OU PASS AG E DE LA PUISSANCE
I
R.,._
Ori'tllCP.t'llKlltl Co•nmK
l'ipt>ed'luaqw
l dlit"19
r:::::::7.l - ~ ---{-;;;;.;,;-- ;
~ --------J
hi dutdt hOlatflf
I
L.r--~:.:;:;:---i_ _ _:- -.;:.;;:;1
L.---------- -' L- ----~
11 ......... ..
O•n'-:ttifll
I
I r------- ., r-- --- - , r-------- --..., r ----- ,
L--t'~'~'~1~1~h~~ ~ - t-~~~~ _.f .._, L __ ~-w-"':~~- - J -t_ ~~·- J

G]
I
Yl"'6'C'«l .. • L_____iV: d)oftCC"abar••OLJ._H .. .,f ~.;..;;;t1
. ~ ~ L·--·--·J
E··- .. "" ~ ""31
I
I ... - ------- ---- -. .- -----,
L - •M fcholtc (l 'e ntb r :sy:.i~ d.:. lCm c ~..,. 6mltat hlm 1 11t I
'- ---- - - - -- __ J 1------'
I r -- ---- ., r-- ---- .... ,..-------- -, r---- -.,
L _.. E •~u.tdc~ ._. ..,. £A:::otm;.•:no4t'Wtl- .,. f'ai ':lf •1 ,.,,c' v'" •*w ~ -t E .: ~e...ot 1
L----- - J L- -----J L------ - --~ L --- -- J
-5-

JJ1 REAR ARM ANO REAR SUSPENS ION
A. Rear arm removal
1. Place the motorcycle on the center
stand.
2. Remove th e exhaustpipe assembly.
3. Remo ve the shock absorber securing bolt
from t he rear arm and rear fcndet hold·
ing bolts.
4. Remove the r ear wheel axle nut .
~. M :: •IT" ~.=x : :
3. R!.a• .lf':"'l "C . C.";o->="t
5. Remo•Je the rear arm end pl ate bolts and
rear arm holdi ng bolts.
-6-
III BRAS ARRIERE EI LA SUSPENSION
ARRlERE
A. De po se de bras :irriCre
l. Placer la motocyclotlc sur sa bl!quillc
ccn t raJe .
2. Enlc,-cr i'ense:nblc tuyau tl'~cbap pe ·
mcnt .
3. Enle\"<r le boulun de fi.,ation tl'amortis-
se ur du hr-.s onierc ct les boulons de
fixation <lu par e -boue arrit!r.
4. En l ~ver l'ecrou d'axc de la roue ani~re.
1. [;.TeU J· :~ . : '"' J ~ u :Ot.i: imh<
.l~!i~ · :_,t;,C::..icil!'C't-n.l.Wrilti'
3-. BoWo nd-tfL' utiondi;ib r.a:.,:utlUc
5. Enkwr ks boulons de plaque d'ex ·
t:rimite
de bras arricrc ct ks boulons de
fi.~ation du bros arric r¢ .

B. Rear arm install at .i on
1. Finger tigh ten the bo l ts securing the rear
arm.
2. Check th• oil seal lips and bearing in the
end fo r damage wear. Replace as
r equired.
r
1. Rear arm end pl att
2. Col ta r
D. Montage de bras arriere
I. Serrer les bou lons de fixation du bras
arri ere fi La ma i n.
2. Ne pas faire toumer le mo tc ur tant que
vous ne sa , ~e z pas s'i la assez d'huile.
7 .2t 0.1 mm
•0. 283 ±0.04 1m
1. Aaque ~ · 'c:\t r 6mh .: <t c l~:i.s a cr1 e1 e
2. Co l k:ro11~
3. OilSieal
4. Be-a r! r ..g
>. Bar~~ d'Ctu1 c :ieH~
'----------------- --' 4. Ro• km.<"nt
Recommended lubricant:
Bearing: Medium-weight whee l bearing '.
grease
Oil seal: Lithium soap grease
NO T E: -----------~
To avoid damaging the oil seal lip, Apply a
li ght coat of lithi um soap grease to the rear
axle collars. If the collar is di rty, cleanwi th a
rag .
---------- · -·· -- ---
3. Fit the rear arm end pl ate to th e rear
wheel axle
shah, t he n fing er-t ighten !he
bo l ts securi ng the end plate.
4. Tig hte n the rear wheel axle not.
Tightening torque:
60 Nm (6.0 m ·k g, 43. 5 ft -lb)
5. Retighten the reararm holding bolts.
Tightening torq ue:
30 Nm 13 .0 m ·k g, 22 .0 fHb )
6. Ret igh ten the reararm end bolts.
Tightening torque:
35 Nm ( 3.5 m ·k g, 25.0 ft ·lb)
- 7-
Lubrifiant rrco mn1ande :
Roule.men 1: Gra i s.se semi·flu idc i>our
ro
ul emen LS d~ rouc.
Bagu ed 'e tanch.!iie:
Gra.isse de sav on au li th ima
N.B .: _____________ _
Pour thiter d 'e n do mma ger la J C-~Te de b a,gu e
d 'e cancheite, app Liquer une J egere couche de
graisse ~ base de savon au lithium sur les
collerettes de l'axe arricre. Si les collcrcttes
sont sales. lcs ncttoy cr avec llJ\ chiffon.
3. Aju st er la plaque d'cxtremite de bras
aniere sur l 'axc de ro ve arr i Cre, puis
serrer Jes boulo ns de lixation de cette
plaque 11 La main.
4. Serrer l'ecrou d'axc de la roue a.ni~re.
-:
Couplede serrage : 60 :-im ( 6, 0 m·kg) !
S. Serrer lcs b oulo r.s de plaque d'cx tremite
de br as arri Cre au t·ouph! s¢cifit.
Coup le de serragc; 30 Nm ( 3,0 m·kg)
6. Serrer les boulons d'cxtre m ite de bras
arri~re au couple specifi6.
I Couple de serrage: 3S Nm (3,5 m-kg)

IV MISCELLAN EO US
A. SPECIFICATIONS
General
·Model:
Mo<fo l (1.8. IA. No.)
Frame 1.0. & Startin g Numb er
Engine 1.0 . & Startin9 Numbc1
Dim ens.ion:
O\ttiro ll Length
O\•era !I Widlh
Overatl Height
S!i t H eigh;
Wh.oolbast
Min.imvm Ground Cit«~
- ·
Weight;
~ ::~·
um Tvrning Radiu$
Engine
Oesi;nptlon :
Eng- i nie Type
En ;!ne Mode l
Displacement
Bo.-. iit Stroks
Comp1ess i on Rat io
Starting System
lg nition Svstem
lub ri~ tio n System
1 Cvli
ndtr: ·
Ma te rial
3o re Sii:e
T ~p u· lir.iit
Out of P.ovnC Li !!" '-'''- - --- -
rcr :
: ·s :..:-: C:: ;:~-:ce
:.-: r::'"IO\"i~ ~ u
= 1 ~ : - ~ : ::; :
?1 s:-:.:"1 Ri~; ~i~n
?i r._o n ~ : ni; 0'!5i£:l
.:li~g End Gap (ln mHe-0)
~hg End Gap (Installed)
Ril"ig Groove Side C! ur¥tee
Ring GJoo <Je Side Clearance
Small End Bearing:
Typ0
Sig End Searing:
Type
ffO?I
12nd)
(TO?)
12ndl
fT o?)
12nd )
I
1
f
I
!
I
5N7
5N7·000101
SN7·000101 -
1,600mm 1 63.0 in)
7 20 mm 128. 3In)
1 ,080 mm 142.5 in)
760mm 129.9 in )
1.075 mm (~2.3 in)
125 mm (4.9 in)
--.
50 kg (110 lbl
1, 600 mm (63.0 in)
Ail' cool td 2·ttrok.e, G as oline, Reed val\·e
SN7
49 cm> (3.0 cu. i nl
40,0 mm x 39.2 mm fl.575 In x 1.543 in)
6.0 : 1
Kick
1 COi
Scp ~ra te l~r i c;tion (Yamaha Auto!u bel
Sped al r..ei.:t hon
40 mm (1. 57 in l
0. 05 mm (0.002 in)
0.01 mm (0 .0004 i~'----- - --- - - -1
O.OJS - 0,047 mm (0.0014 -0.0019 in)
40.25 mm. 40 .SO mm {1.585 in, 1.594[n)
Kt\"ftOne ring
K~onc ring (w i th expande rl
0.15 - 0.35 mm 1 0.006 -0 . 00 14 i nl
o. 1s -0.35 mm f0. 006-0.00 14 inl
0.03 - 0. 05 mm 10.001 -0.002 in)
0. 03 - 0. 05 "'m 10 .001 - 0.002 on)
Ntedle be1:ing
N eed lebeoriog
- 8-

Conbl>aft:
Crrishoft As,.mbly Width tFl
Crankshaft 0.ffection (Al
CoMetting Rod ll'9End S<de ctearanct (C)
CoMetting Rod Smlll E nd 0.fio<tion ts)
Crank B e:iting Typt
Cr an k Ooarfog Type
Cran~ O;i Type
Cr""1c Oil St-at Type
Clu1ch :
Cknch Ty pe
_s_
Clutch Shoe - Th icknen
(L th l
(Ri!ll>tl
(Loft)
IRigllt)
Clutch Shoe Sl><i"9 - Fr .. Length
Clutch S~ Spring -S.t Vl oi ght
Clutch
·i n Revolution
Ctutch·staU Revolution
Tran smission:
I
I
38 ~ g . OS mm (1.50 ~~.
002
in)
0,03
mm (0 . 0012 inl
0.35 -0.55 mm (0.014 -0.021 inl
0.4 -o.a mm (0 .016 - 0.031 ml
6203C3
6203C,
SD17·35·7
$023-35-7
Wet# Centrif°'ail au1onutic
1.0 mm (0.04 kl)
3~ . 5 mm (i.36in)
3.6kg 17 .94 lb)
2,700rlmin
3.500 r /r<O o
19/1511.267)
54/ 11 (4 .009)
1
Primary Rtc"uc1ion Ratio &: Method
Seconduy R~c tion Ra;iol'\ & t.lt- th~
T ran tm1nionG!!H 0 :1 O:.ram: i ry &i ypt
Tttth ihtio
ht
l--- ------- 2 ::";;: d ___ _
Exch an ge: 0 .45 ~ I OAO IMP. qt l I
Total 0 .5 ~ t0.44 IMP q t)
+
Yamaha 4-<:ycl e oil or SAE lOW/30 moto1 oil
G3/22 (2.864)
~ 1.848 ) __ __ . ~
K id< Start e 1;
1- - T -' v -' "° ----------------r- R - •t _ h_c•_ t _tv-'pe - ~ ~ --- ------~
lnta~ t : I
Air CIHnet Type O ile d form tubbre r
Reed Val..,:
S.nding limit 0.8 mm 10.031 in)
va ;ve lift 4.8 .:: 0.2 mm (0.19 J. o. ooa inl
T;ghteni rig Torque ---------l11- o ._ .s _N_ m_c<_o.o_s_M _· -l<s ..;;:.. 'o _ ._ss _ 1t_·lb_I ____ ._
C¥bu1e1or:
Type & Manufacturer VM12 !MIKUNI)
1.D. Maol< 4J200
M11in Jct (M.J.) # 72.S
Air iot (A.J.) , 2.5
Jot N°""'l .. clip Posit; on IJ.N.I 3Xl - 2
NeroleJet !NJ .I E·6 (3301
Cut•way IC .Al 4.0
P ~ot Jet (P .J.J ;','40
Ai r Scre w ( turn< out} IA.S.I
1
1.J/4
Starter Jct !G.S.I if 30
Float Level (F .L.1 22*1.0 mm (0.87t 0.04 ; n)
Engine Idling Speed 1.700 min
-9 -

Lubrication:
Autolube Pump-Color Code
Autolube Pump ·MiJ\lmum S\roke
Avto lube Pumo · Maximvm Stroke
011 Tardt C.apa city
Oil Gmfe
Chassis
Fram e:
Frame Desig n
Steering Syst'!m:
Ca$ter
Trail
Number & Sizeo f Ba ll ' in St eeiing Heid:
Upper Race
L.ow~r Rae~
Lock to Loc k Ar.gl e
!
ffont Suspensio n:
Type
Oa.npe1 Ty pe
Front Fork O.ahion TraYt:I
Rtat Suspension:
Ty pe
Damper Typa
Rear Wheel T nvel
Fu• I T•n l<:
<'..apac i t · ~
Fuel Grade
VJh~el :
nrc Si ze (Front}
IRearl
Tire pressur-e Cf rontJ
{Rear)
R im Rvn Out Lim it fFrontffiear):
Vertical
Lt er al
Drive Shti f-t:
Lubr icating Gre ase : Grade
Quant i ty
Brak e:
Front Sr ake::
Type
Or um Oia""ter/Wt¥ Lim it
Shoe Diamet er x Vo'"td th
Lining Thickn0$$ /\' loar Li mit
Shoe Sprinw Fu1e Longtll
Rear Breke:
Type
Orunl Diameter
Shol'.! Oiametot x \'/idtti
Lining Th
ie kne u/ Wc4r Li mit
Sho e Spring Free L eng th
I Yellow
I
.
0.25 -0 .35 mm co .0 10-0. 014 inl
l.00-1. 15 mm (0.040- 0. 050 inl
0.7R {0.6 I
MP. qt l
Air co oled 2-eycle englna oil
P1
es1Cd undetbont:
2s •
86 mm 13.39 in)
26 pcs 5132 in
26
pc s 5
/3 2 in
100•
Tel e<:opk: fo .. k
Coil spt i .ng. G1tasedamptr
45mm ( l.8 in)
Unit$wing
Coil spring. Oil damper
50 mm {2.0 i nl
; 2
.8f 10.6 I MP . g3I)
Regul ar leaded gasol in e
2.00·16-4PR
2.25·14-4?R
l.25baf (1.2Skg/cm'. 18psi)
2.00 bK (2.00kg/cm'. 28 psi)
0.7
mm (0. 028 in)
LJ mm (0.051 in)
Lithium baso whool ba ~r i ng 01e11se:
1 0. {0.35 oz l
Orvm b1ake
~mm 13.15 m) / !)80.S mm {3.17 in)
6 80 x 17 mm (3.lS x 0. 67 i nl
3.5mm/2.0mm 10.14 x0. 08in)
44 .S mm (1 . 75in l
Orum brtke
' 9)80mm {3.15 i
o) /\08 0. 5mm 13.17 io)
98 0 x 17 mm 13. 15 x 0. 67 inl
3.
5mm/2.0 mm {0 . 14 in /0 .08 inl
44.S mm (1.75 i
n)
-10-

Ele ct ri ca l
Ignition System:
Voltage 6V
Pulser Coil Rcsinance fWhhe/Red· Bl ack) 19 .111 • 10% 11 20°c (68°Fl
Oiarge Co il Rcs;s tance (8'tek/Red·81a,k) 30 1.2n t 1 0.,," 20°c <68°F1
lg<>ltion Timi ng (8.T.D.C.l: 0.94 mm (16°15,000r/mi nl
Ignition Coil:
Mod el /M rmufact ur er C2T4/ YA MAHA
S114rk Gap 13kV/500 r/min, 1 2kV/8 , 000 r/mln
Primary Windjng Aesis;t~noe
I
1.6 lc$! ± 10% at 20°C l68°F)
Second.3ry Winding Rtsistanee
6.6 kfl *20% •• 20°c 1ss°F>
Si>•r1< Plug:
· rvpe/Manufac t ure 8? 4HS INGKI, W14EPL IND)
Spark Plug q•P 0.6 -O.i mm (0 .0 24 - 0. 028 inl
Sp11k Pl'ug Gap Resimnc:e s kn t 20% .. 20°c l68°Fl
Charging System:
Ftvwhe P. I Magne t o:
Model/M.111ufacturer F5 N7·MO/YAMAHA
Ota:rging Output Night 1.3A or more at 4,000 r/mfo
2.0A or ltss <lt 8,000 r/min
ligh ting Vol ta99 6. SV ormote at 4,000 r/min
7.7V or fess at 8.000 !'/m in
Ughtin;1 Coil ResiRillC8 (81ue- ·Black)
0.1nn ; 2Q% at20"C(68 °F)
01-arging Coil Resistanc:t IV 1'hite· Bladc)
026811 • 20% •t 20°C (68 °FI
Aectifier:
Type/Ma
nufbotu rer Singlt phm , Hol l/T OSHIBA
Cap:1otv 3.2A
Withs:ai'KS Vohage 400V
Vo lt t!)9 ReguJilor:
Ty pe A.C. R eg\Jlator
Mod e l/M a mrfactut~r
4F4-60/STANLY
R~lning Voltage 7.5 >: 0.SV
Allowab le Amperaga SA
Bana r y:
Model/Manufacture
6N4 ·2A ·2 /N IPPON
C3pac ity 6Vo4AH
Charging Rato 0.4A x10 hours
Specific GHh· ity 1. 26 .. w•c f 6B' FJ
Lig ti t in9 Svstem:
I
Headli9i< Type
Semi · se11td btarn
fieodllght Vilattagc 6V, 25W/261V
Tai l/Stop tight Wattage 6V , 5.3 W/25W
Flasher Light
Wa tt ag e av , 1 1w
Flasher Pilot Llgh1 Wattage 6V, 3\V
Mtttr Ught W1tta;e 6V,'JW
High Be:im lndic-ator Light W11tta!Je 6V,3W
Oil Wa rning Cn dic 11 otr Li gh t Watt ag e
6V ,3\'/
Stan Jnd ic ar or Light Watt&ge 6V ,3W
Fust:
RotinglO'ty 1
0A/1 pc
-11-

T ith tening Tor que
,...,,
I
Sm
I
TlghtimS1ig lOfQ\lt
__ __t__
I
Nm
'
mkg
I
ft~b
Enaint:
---
Cy l indtr head holdint nut
--1 ---;:;s --·1101 1.o I 7
SPl<1< pilJ9 I M14 I 20
I 2.0 I 14.S
Oil pumo IC.sel I MS ! 6 0.5 I 4
Kick crank
i M6 10 1.0 7
--
Reod vatvt (Manifold) I
MS
'
10 1.0 I 7
ExhNll pipe ICVli:><!tr bocly) I
M6
: 10 1.0 I 7
ExNust pipe (~ c:o>e R/H) M8
20 2.0 15
OtJinbOh M8
20 20
; 15
-
c. ......... ~ 16
10 1.0 7
CtMlk .,,. ""'"" iR/HI M6 10 1.0 1
t--
Primwy dtWe gHt
M IO 40 4.0 I
30
-Housing"°""'
IRi!;tlt hous"'91 i
M6
I 10 I 1.0 I I
Cronk oU so l plate ( 0"'1 k as • R/ 11 ) I M6 I 10 I 1.0 I 7
Sontlng COVtr (Ct ank cast U Hi
I
M6
I 15 I 1.5 '
11
Bearing COYe1 (Rear housing)
M6 15 l .S
I
11
o ,; .. n pi"'on ICt•nk....., l/HI
I
M45
I
llO
I
6.0
I
43
°'""" puion (R..,, housing)
1.135
I !iO I
5.0
36
0.Wd:
Front wheel $haft nul MIO
I
40
I 4.0 I 30
Rt 1r whed ihaft oot Ml2 I 60 I 6.0 I 43.5
H1n0i.t>a1 fitting bolt I
MS
I 30 I 3.0 22
E~int mount bolt I MIO
I 35 I 3.5 ! 25
t- FooltOSt I
MS
I 25 I 2 .5
I 19
Aear r ack ( Fr a mes l I MS
25 I 2 .5 19
R1a1 rack lFl a$hedfni.mel
I
MS
I 20 I 2.0 I -
15
Rt ar G.IShion (Frame) I MIO
I
40
I 4.0 I 30
RNrcvst.on IHouslngl
I M8 30 3.0 n
Rar CU>h l on (Rnr arm) MS I 30 I
3.0 22
Rut orm (R/H) IEng;,,.I I 1 ~ 8
I 30 I 3.0 • 22
Rur111n(Er.dl I M8
35 3.5
25
C...tentand i M6 10 I 1.0 7
-12 -

IV D IVERS
CA RACT ER.IST IQUES
C4rntrali 1 ~
M od! le :
~fod<Ie (No. l.6 .M .)
1 .0.N nu in 6ro de s6r ic de ddpiut du c:1 drc
1.0 .et nu.-n6ro de si6 rit de d6p11 11 du mo t cur
l>lmensian:
Longuoru: totale
Luie.r totale
Hau1cur totak
lbu""'1ciela..tk
Emp;itt~mcnt
Garde t:c sof mi nlm:lle
Poid.:
Poids r.c t
---porro 1m 11. nces :
R.Jyon de braquagt minlmum
\to1 cur
C>nerip<1on:
Type ditmo;.eu.:
M~e c!u mott>.rr
Cylin d iO.
Al 613g• x Cou"c
T:mx dt: c<Mnprc u!on
Syslime de dc!m:a1roie
Syst!mc d':>lhun•io
Syn!mc .:S e 1ubnr1 :it!on
Cyll ndre:
Ma~risu
Tdledet'uuv
Um1t.e c!c co:uoN
Umitt d"ovalmhun
P inon:
J iu de pi.»ton
.__
Piston pour c()u! de rC.paflatlon
S.gmen 1s:
Fonnc de segrnen ! {Somin<t)
(2eme)
Eci ne me nt des e:<ttlmhds: (Somme!)
do ~t(mh en~} (itm.)
Jcu latcral de""'""' dar. • u Pl"
(Sam:mt)
(2t;no}
Rou le men1 de p:rd de bi cll< :
Type
Roulrment de tel•
de bl• ll e·
Type
I
SN7
Sl\7·000101
SN7-00(ll01
l.600mm
720mm
t.OSOn-.n
760mm
l.075 """"
l2Smm
so kg
I l.600n1m
Rtrro1c11 .,., ••• 2-umps. ......... d11;><1J 1lu1h1n
SN7
49crn>
40,0
mm x 39, '.! rn:n
: 6,0 : I
Kick
C.0 . 1.
Lub11t1mion s!p•i<t (Y:m»h• Au1o!ul>t)
Fon1e •¢<We
.&Ornm
0,0Smm
0.01 mm
-- ---- ·-
0,03 ~ 0.047 mm
40,2S mm . 40,SO mm
----
Sepncn1u•p61oldol
Seg mcnl 11 •p6>.o1d al ( A°""' upan,.r)
O.I S-0 .3S m:n
o.1S-0 .3S m:n
0.03 - o.os .... .,,
0.03 - O.O Smm
Roulemcn l ~ • iJUilles
-
I
Roulcmenl ii a}guillts
-13-

V'~ebrequin:
I
38~ g.os mm
Lar&<ur de !'ensemble vilcbrtqUin (F)
Voll• de •ilebrcquin (A)
om mm
kou J a1eral de teto de biellc(C) 0,3 5-o , ss mm
~tl<Jtic>nde pied de biellc {S) 0,4 - 0, 8mm
•
-l~c
T)'pc de ·Joultment de vilcbrcquin
(Gauche) 6203C>
(Droi1) 6203C,
Typo de baguc d'•tanoM i l~ de •ilebrequin
(Gauche)
SDl7-JS - 7
(Drol t) SD2J- JS -i
F.mbrayay:
Type d'cmbr•yagc Humidc , centrifuge. autom21 i q~
Mitho iJ c d'emb 1 ay1gc - Cpa j s.seur
i . Omm
Ressort de mkhoiu. d'ttnbc:.ayagc - LongcurUbre 3A,5 ;n m
Re u.ort de nlicitoi re d'e-Mlbri}'tge -F0tee n10ntC
3,6 kg
JU:gime d'tmbray•z. e 2.7 00tr / mn
Regime de dlbrayage 3.500 rcimn
T r :i.m;nission ~
'faux el m~1hode de reduction primaiie
19ilS(l,267)
Taux e1 mCIJ'iode: c;k t&I U:c tion sC.combhe
54/ 11 (4,909)
QoJan ri1eet type- d'huUe de uansmis.siorr V1dang(: :014 se
l1ui\e Y!!.rttlha 4- temps 011 huile motcur SAE I OW / 'JO
Ta ux de rtduction ....
63122 (2.864)
Urne 6Ji33 (1 ,848\
Kick.starter:
Type Ty
pe a cloquet
Adn 1i ss i on:
Filue 3 air - T-ype/Ouan1i1C CiO'..ltcho ~t mouue huil~
O•p•ts ncxibl.,.
Lim i tc de tOrS i on 0.8 mn>
l..c'lte dt clopct 4, 8:t0 ,'1mm
C.Ouple de serragt 0,8
Nm (0.08 m · ~g)
Carbu1attur:
T}•peet f ab riquc V:.112 (MIKU NI)
Rep<rc d'l.D. 4J200
Gideirprincipal (MJ.) #
n, s
G !t l eu rd'tir ( AJ .) 2,S
Aiguille dc lielcur -Positioo de l'•amo
(J.ti.) 3XI
-2
Cicleur:. i i $Uille
( ~J . )
£-6 (33G)
EchallC!1U rt (C.A.) 4,G
Gicleu1 de Dlerili
(PJ.)
#40
Vi.s ~edo~ge d'air (tours en a.rot.re) (A.S) 1·3i4
Cideur de st :mc r (C.S.) ,;;30
Nive a\1 du OotteU .J (F.L)
2.2 '!: I Omm
Regime, de raJenti du moteur
1.700 trf mn
-14-

L.ubrifico~on :
Pompc Autolubc- Code de coule-ur
Poro:>e AutNubc - Course minlmal-i!
PomP e Autolu. bc-Cou rsc maxi.male
C1J>'dl6 du rosen'oir ~ ltuilc
Crade. de l'hui!e
Partie·Cycle
Cacht:
f.onoo du cadre
SystOmt de di rtc.tion:
Angle clochasse
Ch use
l'ombre .. t:U lle de d>tU la lite de roun:he:
CuYC tlC sup(rieure
0..Yett einfCdeu(e
AJl$1c de OOt Cc t but.!e
Suspension ava nt :
Type
Type <f;unordsseur
OCplac:cme nt de c ovs 5inet de iourchc avant
Suspons.ion ~rrCro :
Type
Type
d'amo11Js.seur
I>Cbatlement de roue arDCre
RiSCTYOlf 3 f'.Htnce:
C.pacltl
Crlde de l'csstn:e
R oue:s:
Taille du pn•u (A ,·.at }
(A rribrc)
Pr'.>Sion de i<>-'Dogo (Av an t)
(Arri< re)
Liniile dt voilede jante (A'f'antf Arrii!re)
Verrj c;al
L.11l ral
Ac bro de m 1rurni53ion
Gr:us.se do? lubrification: Gra de
Quantitt
Fre ins:
Fr ein avan t
Type
DiamCh 't du tambaJci.Umi te d'usurc
Dfam C hc x l,.oirgeur de m3choi.re
E.pafs.~1 de gamitu1c,'Limite d'usurt
1..on,gue r l. ibrede C't?$SOtl de mi:hoirc
Frc:Jn arrltrc
l)·pe
OiamCtrc du tarnbou l'
Oi:. 1n!tr ie x 1.:argeur de mkhoicc
£pa.i:Sscur de g:arnirurefLirnitt d'wuce
Longuer Ubrc de r~ssoc-t de mk.hoira
Jaunt
0. 25 - 0,3S mm
1.oo-1.1srnm
0,7R
Huile pour motcur 2· 1cmps rcfroidi parair
C.drHn 1ole omboulic
S6mm
26 pc s. 5132 in
26 pes. 5!32 in
100•
Fou rc he t~ l cSC< 1 p1 quc
Re ssort hi!lk: oni al, Amortisscur 3 giai~
/Smm
Bras oscill:mt
RttSO<t ht?icotdat, Am ortiueur a Au.ik
SO mm
2.82
Esstr.u normale
2,00.l64 PR
2.2S-1<4 PR
l,25 b•t (1,25 k&' 'crn')
2.00bor(2.00kglcm')
0.7mm
l,3mm
Gnds.se \\base de li thium pourroul emei:'IU de roue
I Og
Fr eiri b 1a :nbour
o>SO mm : ~80.S mm
\\SO• 17 mm
.l, Smm.12 , 0mm
44.S mm
Frein~ tambour
9SO mm I ~.5 mm
c>80 • 17 nun
3.S mm /2 .0 mm
44 ,S mm
- 1 5-

P>rt ic Electrique
Sy;i<me d'allumal)l! :
Tension
Res istance de la bobiDc du pulseur
(BlancfRous•·Noir)
Resistance: do- b bobi rn: . de d \ ar~e
(NoiI/Roogc-Nouj
Av:uice ii r.UUni•£t (B.T.D.C.):
Bo bioeJ'allum:.gc:
~odlle/Fabriqu e
Et i ncellemenl
Rtsistanc c: de l'cnrou!ement pdma!rt
Rf~is c ant c dt l 'cnroulem~n t suondairc
Bougi~:
Typcffi;briquc
Ec3r!tmtnt dtt 'k~tro:!ts
R0si:USfl(C: de l°CC3t lment dies tltctroJt."1
Sys 1 Cm di!' charg e:
Volant ina c:n~cique
~ lodal•!Fabr!quc
D€bi1 dt t:hargt
Rfsiuanccde la bobine d'ecl:iirag.:
(BIC<J·No ir)
Re s.iu:u1co de I :i bobi.nc ch arge
(Bl an c- Nol r)
Redre5$tur :
6V
l9.7H: l ~ 3 20cC
301.m ~ 1 <r:< a Jo
0c
0,94 mm ( 16 °,S.000 or :m n)
C:!T~ : Yam:aha
13 kV!SOO u!mn. 12 kYi8.000 lr/mn
1 ,6 kn± 1tma :o •c
6.6 kfl ± 20~ 3 '!0°C
lll'JHS ('.'!CK).W14EPL (ND)
0.6-0.1mm
H!l t 20%3 20°c
l' SN7 -M OIY Al> IAH A
Sui r J ,3 A OU plus i 4.000 tr/in=-
2.0 A ou mohts ii 8.000 uinm
6,SV OU plus:\ 4 ,CXX> 11/m:a
7,7 v oujmois a 8.000 or.'mn
0,1 nn ! 20\H 2o•c
o,26m ~ 20% a 20•c
Typt/Paboiquc MonQp lia !C simple .Jt<m,.etfTOS lll ll.~
C•p;ci~ 3.2A
Te.nsicn de rtgul'lt: .:.oov
I------' '-- ---- -- -·· - i.- --- --- --- --
Regufateur de ctnSion
T\' PC
~i~ctete
1
1
Fabrlque
Tcn<ion de rtiula1 ioo
Ampira~ 3 dm asible
B1ttcri::
~ t o:H:!e Fabnqu::
Cat:'.1dte
Ch_31g.;:
Gr a\• i tt spCciliq ue
~"$ time d'.!claingc::
Type de ph;ut
Puiu.· m::t: du pha:e
P\Jistance
tlu f« 1 :mCr.:}Stop
Pu i s;.aoce de cHgnoteurs
Pui ss.an c-e du t6noindesc .Ugnoreurs
:Puis sanct do 13ftlpe de <:o:rip1eur
Pu issancc. du timoin de feu deroute
Puiss:ance du tim oin de nivc::.u d'huilo
Pui:ssance du ftmoio de dem-.uci~
Fuisblc:
Capaci t6/Qt6
Rl ~ l •t •or C.A.
4P4-60!S
TA N LY
1.510.SV
8A
6~:...\-1 . ~lPfOS
6 V4 AH
0.4A x 10 b~ures
l .:6t 20 'c
FW...~au sr:ni·mooobf()('
6V .2sw; :sw
6V. s;.nv12sw
6 V, 17W
6V,3W
6V, 3W
6V,3W
6V.3W
6V, 3W
IOAll pc
-16 -

Couple de Sen age
Partit Taillo
CouriJe dest1tage
Nm m·l<g
:\toteur:
Ectou do fiicat i on dt culasse M6 10 1,0
Bou gi e Ml4 20 2 ,0
Pompeii huilc M5 s o,s
PC dale de klck M6 10 1,0
Oapc:u ikxlbles (Tubclure)
)16
I 10 1 ,0
Tuyau d'lchappement(Cylindre) M6 10 1.0
Tuya~ d'O.htppemcnt(Carler droil) MS w 2,0
Boulon de vkbngc M8 20 I
2,0
Carter M6 10
.
I.0
:
C oU\ 'C- rCJe dec:ulcr (O) M6
10 1.0
Pi g.non d'111aquc prima i rc M IO 40 4, 0
C OU \ 'c1clc de bollier (B oltie1 droit)
I M6 10
1,0
Pl aque de baped'eundeire I
de •iltbrequin (Crner droit)
I
M6 10 1.0
CO'.JVUdt de r0c.1ltm~n1 (Caner dcc:Mt) M6 15 1,S
Couvercle de rou!~ment (Boitit:r .trri~rt:) M6 I IS 1,5
l'lgnon
men! (C.. t or gauche) ~ l 45
I
60
6,0
Pigoon men6( l lo iti tt ani~r.e) M3S so S,O
l
Panie·cycl e:
Etrou d 'a xe de r oue 3.\" a nt MIO 40 ~. o
Ec:1ou d 'ax e de ro ue arr~ce Ml2 60
6.0
Boolon de ri.x:. r ion de sui don MS 30 J,O
Bou!on de mon1;,1gc du mo t eur
MlO 3S 35
R<pos<-?ic d
MS 2S
2.5
Port .. ba.gages arr~r< ( C:!Ore) MS 2S 2.S
P0<1•·bapJ<> arrilrt (Qiylo1<ur!Cadic) ~l8 20
~ . o
Amorljs1<ur •nitre (C•d;e) MIO 40
! 4 ,0
Arno r tissem arriC re( Ca ller) i MS 30
' 3,0
A mo r tii:scur arriC r e: (Bn .s 3 rri i: 1e ) I
MS 30 3,0
Bras
arr i e•c (D) ( ~lotcur)
I M8 I 30 3.0
Bl' asarri C:e
M8 35
3,S
tJC<i,uim: centraie M6 10 1,0
- 1 7-