Suzuki DR350 User manual

SUZUKI MOTOR CO RPORA TJ ON PRINTED IN JAPAN OCTOBER '90 @
99500 - 43019 - 03 E
(,.)

FOREWORD
The SUZUKI OR350 was designed to o ffer su-
perior p erfor man ce thr ough lightweight de si gn,
four st roke - power , engine coun t er -b alancer,
drysump lubrica t ion sys t em and link ty pe rear
suspen tion.
This service manual has been produced primari -
ly fo r experienced me cha n ics whose job is to in-
spec r, adjus t, repair and service SUZUKI
motor cycle . Apprent ice mechanics and " do it
you r self" mechanics w ill also fi nd th is manual to
be an extremely useful guide .
The OR350 . manu fac t ured to s tandard s pe ci fi-
ca t ions. is (he main su b jec t matter of th is manu -
al. H owever. the DR350 machines distribu te d in
your coun tr y might d iffer in mi nor re spec ts fr om
t he standard -s pecification and. if the y do , it is be -
cause some minor modifications (whi ch are of no
consequence in most c ase s as far as servici ng
is concerned) had to be made to comply wi th the
st atu t ory requiremen ts of your coun tr y.
This manual contai ns up ·to· date information at
the t ime of i ts iss ue . Later made mod i fications
and changes WIN be explained to ea ch SU ZUKI
dis t ribu t or in respec ti ve market s, to whom you
are kindly requested (0 make query about up -
dated in format io n, if any .
SUZUKI MOTOR CORPORATION
Mo tor cycle Service De partm en t
GENERAL INFORMA nON
AND TUNE-UP PROCEDURE
ENGINE
FUEL
AND LU8RICA nON
ELECTRICAL SYSTEM
CHASSIS
SERVICING INFORMA nON
DR350S
DR350M ('91-MODELJ
DR350SM ('91-MODELJ
DR350N / DR350SN (' 92 -MODELJ
DR350P / SP ('93-MODELJ
DR350R /SER (' 94 -MODELJ
DR350S /SES ('95 -MODELJ
DR350T / SET (' 96 -MODELJ
DR350V / SEV (' 97 -MODELJ
DR350W /X ('
98 ,'99-MODELSJ
© COPYRIGHT SUZUKI MOTOR CO RP ORA TION 1990
10
11
13
14
15
16
17

VIEW OF DR350L
LEFT SIDE
RIGHT SIDE

ON TENT
VIN AND SERIAL NUMBER LOCATIONS . • .. . . ... .. .. .. . .. . 7-7
FUEL AND OIL RECOMMENDATIONS .. . . . . . . . . • .. . . . .... • 7-7
BREAK - IN PROCEDURES .• . ...•....•• ........ . . .... •... 7·2
SPECIAL MATERIALS .. .....•. . ...•...• . . ...•. . . .. .. .. 7-3
PRECAUTIONS AND GENERAL INSTRUCTIONS .. . . . . .. . . • . • 7-5
SPECIFICATIONS .. ........ . .. . . . ... ... . . .. .. ..• ... . . 1-6

1·1 GENERAL INFORMATION
VIN AND SERIAL NUMBER LOCATIONS
The frame serial numb er or V.I.N. (Vehicle Identif ica tion
Number) <D is st amped on th e steeri ng head pipe. Th e en·
gine serial number ® is l oca ted on the rig ht side of th e
crankcase .
These number are r equired especially for regist ering the
machine and order ing spare parts .
FUEL AND OIL RECOMMENDATIONS
FUEL
For U.S.A. model
1 . Use only unleaded gasoline of at least 87 pump oc tane
( a...pt method) or 91 octane or high er rated by th e
research
method.
2 . SUZUKI r eco mmend s th at cus tomer s us e al co hol free,
unleaded gasoline wh eneve r possible.
3 . Use of blended gasoline containi ng MTBE (M ethy l Ter·
tiary Butyl Ether) is permitted .
4 . Use of blended gasoline/alcohol fuel is permined provided
th at it contains not more than 10 % et hanol. Gaso-
line/
alcoho l fuel may con tain up to 5% methanol if ap-
propriate cosolvents and corrosion in hib ito rs are present.
5 .
If the performance of the vehicle is unsatisfactory while
using blended gasoline/al cohol fuel, you should swi t ch
to alcohol free unleaded gasoline.
6 . Failure to
follow thses guideline co u ld possibly void ap-
plicable
warranty cove rage. Check w ith yo ur fu el sup -
plier
to be sure th at th e fu el you intend to u se meets th e
requir
emen ts l isted above .
For
CANADA model
Use only unl eaded gasoline of at least 87 pump octane
! 6.j-M me th od) or 91 octane or high er fal ed by th e
Research
Method .
For
other models
Gasoline used should be graded 85 - 95 oc tane or higher.
An unleaded gasoline is r ecommended .

ENGINE OIL
For U. S.A . model
SUZUKI recomends the use of SUZUKI PERFORMANCE 4
MOTOR OIL or an oil which is rat ed SE or SF uner the API
(American Petroleum Ins titute) classification system . The
viscos it y r ating is SAE 10W / 40 . If an SAE 10 W/ 40 motor
oil is not available. sel ect an alternat e according to the right
c hart.
For other models
Be
sure that th e engine oil you use comes under AP I clas-
s ifi cat ion of SE or SF and that its viscosity rat ing is SAE
1 0W / 40 . If an SAE 1OW/ 40 mo tor oil is not available, se l ect
the oil vi scosity a cco rding to th e right cha rt .
FRONT FORK OIL
Use fork oil # 10
99000 · 99044·10G , SUZUKI FORK OIL # 10
BRAKE FLUID
Specification and class ifi ca tion : DOT 4
99000 · 23110 : SUZUKI BRAKE FLUID
WARNING :
GENERAL INFORMATION 1·2
MULTIGRADE
10W 30
* Since the brake syste m of this motorycle is filled with a glycol -based brake fluid by the manufac -
turer. do not use or mix different types of fluid such as silicone -based and petroleum -based fluid
for refilling the system. otherwise serious damage will result .
* Do not use any brake fluid taken from oil or used or unsealed containers .
* Never re-use brake fluid left over from the previous servicing and stored for a long period.
BREAK-IN PROCEDURES
During manufacture only th e best possible mate rials are us ed and all ma c hined parts are finished
to a very high standard . but it is still nece ssary to allow the mov ing parts to " BREAK·IN" befor e
subjec ting th e engine to maximum s tre sses. Th e future pe rf ormance and reli abi lity of the engine de -
pends on th e care and restraint exercised during it s early lif e. The general rules are as fol lows.
Keep to th ses break-in thrott le p osition
Initial 10 hours : Less than 1 /2 throttle
Up to 15 hours : less than 3/4 throttle

1·3 GENERAllNFDRMATIDN
SPECIAL MATERIALS
The materials listed bel ow are needed for maintenance work on th e OR350 and shou ld be kept on
hand
for ready use. These items supp l ement su ch standard mat erials as cleaning fluid s. lubricant.
emery clot h and like. H ow to use them and where to use them are described in the t ext of this manual.
METERIAL
For U.s.A . model
SUZUKI SUPER GREASE " A"
99000 · 25030
SUZUKI SILICONE GREASE
99000 · 25100
SUZUKI MOLY PASTE
99000 ·251 40
SUZUKI BOND NO. 1207B
99104-31140
THREAD LOCK " 1342 "
99000 · 32050
For other mod els
SUZUKI SUPER GREASE " A"
99000-25010
SUZUKI SILICONE GREASE
99000 ·2 51 00
SUZUKI MOLY PASTE
99000 - 25140
SUZUKI BOND NO. 1 215
99000 · 31110
THREAD LOCK " 1342 "
99000-32050
PART
• Throttle grip
• Odometer gear bOI(
• Side stand pivot
• Oil seals
• O-ring
•
Front and rear wheel hub bearing
• Steering stem boa ring
• Cushion lever bearings. dust
seals and spacer
• Swi ngarm bear ings
• Caliper skle
• Caliper ute and piston
PAGE
2-2
2-2
2-2
3- 32
3- 47
2-2
6-1, 20
2-2
6· 16
2-2
6-28
6-28
6·5
6· 23
• Rocker arm shafts 3· 15
• De ·co mpression shaft 3·15
• Valve stems 3·21
• Countershaft and driveshaft gears 3·
29
• Piston pin 3- 43
• Camshaft journals and cams 3- 45
• Cam chain tensioner 3· 46
• Cylinder head cove r 2·3
3- 45
• Mating surface 01 l efl and 3- 36
right halves of crankcase
• Front and rear brake caliper 6·5
bolt 6- 23
• Front footrest bolt
• Chain case rear side
mounting
bolt
•
Rear fende, rear side mounting
bolt

GENERAL INFORMATION 1-4
MA T ERIAL
C--- ~ C-~~----C7-C~ ~~ -o C--C----~C------ PART
I- ___ ~ FO ~ ' ~U = .S . A ~- ~ m ~ od = e ~ 1 __ _ For other~m~o ~ d=e ~ I'=--- _ ___ --=--"CC,--------c--,-----,-------j-
PAGE
THREAD
99000 - 32030
"1303" THREAD
99000 - 32110
" '322"
THREAD LOCK SUPER " '303 " THREAD LOCK SUPER " ' 303 "
99000 - 32030 99000-32030
THREAD LOCK SUPER " '303 " THREAD LOCK SUPER " '305 '·
99000 · 32030 99000 - 32100
THREAD LOCK SUPER " '303 "
99000 · 32030
SUZUKI FORK OIL '11-10
99OO().99044-1 OG 11 .0 II
SUZUKI BRAKE FLUID
99000-2311010 .5 LI
THREAD LOCK
99000-32 1 20
•
" '324 "
SUZUKI FORK Oil 11-10
99000-99044-100 11.0 L)
SUZUKI BRAKE FLUIO
99000-23110 CO .5 L)
• Gearshift cam bearing reta i ner
screw
• Pawel lifter screw
• Kick starter lever mounting bolt
• Gearshift cam driven gear boh
• Engine mounting bolls and nuts
• Kick starter pawl guide/ stopper
• Cam sprocket bolts
• Gearshi ft arm stopper
• Magneto rotor nut
• Brake disc bolt
• Front fork 011
• Front and r esl brake
3- 34 , 38
3· 38
3- 34 . 38
3-4
8· 17
3- 38 , 39
3-45
3· 34 , 37
6-'
6· 20
1-2
6· 14
, -2
2·11

1·5 GENERAL INfORMATION
PRECAUTIONS AND GENERAL INSTRUCTIONS
Observe th e foll ow ing items without fail when disasse mbling and reasse mbling motorcycles.
o Do not run e ng ine with littl e or no ven til at ion.
o Be sure to replace pa cki ng s, gaskets. circlips. O-rin gs and co tter p ins wi th new ones .
CAUTION:
Never reuse a circlip . After a eirelip has been removed from a shaft . it should be discarded and a
new circlip must be installed .
When installing a new circlip , cafe must be taken not to expand the end gap larger than required
to slip the eirelip over the shaft.
After installing a circlip, always insure that it is completely s eated in its groove and securely fitted .
o Tighten bolts and nuts fr om th e ones of larger diameter to th ose of s mal ler diame ter. and fr om
inside to outside diagonally, to th e speci fi ed tightening torque.
D Use special tools where specif ied.
a Use speci
fi ed genuine parts a nd re com me nd ed oils.
o
When more th an 2 persons perf orm work t oget her. pay a ttenti on to th e safety of each other.
o
After the reasse mbl y, ch eck parts f or tighteness and operat ion.
o
Treat gasoline. wh ich is ex tr emely fl a mmabl e and highly ex plos iv e. with greatest care. Never use
gasoline as cleaning
solven t.
Warning. Caution and Note are included in this manual occasionally, descri
bing th e foHowing conten ts.
WARNING . . . .. . . The parsonal safety of the rider or bystanders may be involved .
Disregarding
this information could result in per sonal injury.
CAUTION .. _. ... Thses instructions point out special service procedures or precaution s that
must be followed to avoid damaging the machine .
NOTE . ......... This provides special information to make maintenance easier or impor t ant
instructions clearer.
REPLACEMENT PARTS
Whe n yo u replace a ny parts, use only genuine SUZUKI
replacement parts, or their equivalent. Genuine SUZUKI parts
are
high quality pa rt s which are designed and built s pecifi -
cally for SUZUKI vehicles.
CAUTION:
U se of replace ment parts which are not equivalent in Quali-
ty to genuine SUZUKI parts can lead to performance
problems and damage .

SPECIFICA TlONS
DEMENSIDNS AND DRY MASS
Overall length .. _ ... _ 2
165 mm 185.2
in)
Overall width .. ..... 885 mm 134.8
in)
Overall height ....... 1 250 mm 149.2 in)
Whee lb ase ....... .. 1440 mm 156.7
in)
Ground clearance .. .. 310 mm 11 2.2
in)
Seat height ........ 920 mm 136.2
in)
Dry mass .......... 113 kg 1249
Ibs)
ENGINE
Type .... _. _. . . . .. Four-stroke, air-cooled,
GENERAL INFORMATION 1·6
ELECTRICAL
I
't ' t SUZUKI " PEl "
9"' I on ype ....... .
I gnition timing . . . . .. 5 ° B.T.D .C. below
2 300 rIm in and
30 ° B.T.D.C. above
4 300 r/ min
Spark plug ........ . NGK DPR9EA -9 or
NIPPON DENSO
X27EPR-U9
OHC CHASSIS
Number of cylinders .. 1
Bore . . . . . . . . . . . . . 79 .0 mm (3.'10 in)
Stroke .... _. . ..... 71 .2 mm (2.803 in)
Piston displacement. . 349 em) (21.3 cu. in)
Compression rati o... 9, 5 : 1
Carburator . . , ..... . MIKUNI
TM33SS .
single
Air cleaner .. . ...... Polyurethane foam
el ement
Starter system . . . . .. Primary kick
Lubri cation sys tem. . . Dry sump
TRNSMISSION
C lut ch . . . . . . . . . . .. Wet multi - plate typ e
Transmi s sion. . . . . .. 6-speed constant mesh
Gearshift pattern .... 1- down , 5- up
Primary reduction .... 2. 818 (62 / 22)
Final redu ctio n ...... 3. 357 ( 47 11 4)
Gear rati os, Low .... 2.416 (29 / 12)
2nd . . .. 1. 733 126/15)
3rd . . .. 1.333 12 4 / 18)
4th . . .. 1. 111 120 / 18)
5th .... 0.952120 / 21)
TOP .... 0.826 119 / 23)
Dri ve chain ... . ... . TAKASAGO RK520S0
or DA IDO DID .
520VC5. 110 link s
Front sus pens ion .... Tele scop ic, coil spring ,
oil damped , spring
preload fully way ad-
justable , compression
damping force ad -
justab le
Rear
suspension . . . . . Link type suspension
sys tem , gas loi l
damped , spring preload
fully way adjustable ,
compression and re-
bound damp ing force
adjustable
Stee ri ng angle . ..... 45 ° (right and l eft)
Caster ..... . ..... _ 62
D
30'
Trail ..... .. . _ ..... ' 118 mm (4.6 in)
Turning radius ...... 2.2 m (7.2 ttl
Fr on t brake ....... . Di s c
Rear
brake ......... Disc
Front tire size . ...... 80 ' 100-21 51M
Rear tire size . . . . . .. 110 / 100 - 18 64M
CAPACITIES
,
Fuel tank
inc luding reserve ... 9.5 L (2 .5/2.1 USl imp
gal)
reserve .......... 1.8 L (0.5 / 0.4 US /I mp
gal)
Engine oil, oil change . 1700 ml (1 .8 /1 .5
USlimp qt)
Front fork oil ....... 586 ml (19 .8 / 20.6
US /I mp oz)
These spec if ications are subject to change
without notice .

PERIODIC MAINTENANCE
AND TUNE-UP PROCEDURES
ON TENT
PERIOOIC MAINTENANCE SCHEOULE . ... . •.... • . ..• . 2- 1
PERIOOIC MAINTENENCE CHART ..• . • . •. ....•.... 2- 1
LUBRICA TION POINTS ........ . ......•.•..•.. .. • 2- 2
MAINTENANCE AND TUNE - UP PROCEDURES . ... . . . ... 2- 3
CYLINDER HEAD BOLTS AND NUTS, CYLINDER
NUTS, EXHAUST PIPE BOLTS .. •.• . . . . ...•. ... . . . . 2- 3
VALVE CLEARANCE . ... . . . . . . ... . ..•........ . . .. 2- 4
SPARK PLUG . ... . ..... . . • ... . . . . • . . . . . . ... ... . 2 - 5
SPARK ARRESTER . ... .. . . • . . . ... .•.......•..... 2- 5
AIR CLEANER ........ . ........ . ... . ..... •.. ... 2- 6
DE-COMPRESSION LEVER .. ...... . . . . ...... .. . .. . 2- 6
ENGINE OIL, OIL FILTER AND OIL STRAINER . ..••• •.. 2- 7
CARBURETOR .. . . . ... .. . . . ... . ... . ..... . . . .... 2- 8
FUEL LINE. . ................ ... . ... . ... . . • . . .. 2- 9
CLUTCH .. . . .. . ...... .• . . . . . . ... .. .. . ......... 2- 9
DRIVE CHAIN .................... • ..... . . • . ... 2 - 9
BRAKES . .... .. . ... . . . • ... . . . ... .. . .. . •. . . .... 2-10
TIRES .. .... ......... ... . . ......•........... .. 2-13
SPOKE NiPPLES . .. . . . .. . ....... . .... . .. . ... . . . 2-13
STEERING .. . .. . . . . . . . ..... . .. . . • . . . . . . ...... . 2- 14
FRONT FORK . .. . . . ... ... . ... . ...... . .......... 2-14
REAR SUSPENSION . . .. ........•..••......••..•. 2-14
CHASSIS BDL TS AND NUTS . •..•••• • .•.•.• _ •. • . .• 2-15

PERIODIC MAINTENANCE SCHEDULE
The chart below lists the recommended intervals for aU the required periodic se rvice work necessary
to keep the motorcycle operating at peak performance and econo my . Travelilng distances are ex -
pressed
in terms of hours.
NOTE:
More frequent servicing may be performed on motorcycles that are used under severe condi tions.
PERIODIC MAINTENANCE CHART
Int erva l Initial 5
Hours Every 30 Hours Every 60 Hour s
Item
Cylinder head bolts and nuts, cylinder nuts,
T T T
exhaust pipe bolts and muffler connections
Valve clearance I -I
Spark plug
-I A
Spark arrester
-C C
Air cleaner In
spec t each time the motor cycle is ridden and
clean as necessary
De
-comp ression lever I I I
Engine oil and oil filt er A -A
Engine oil hoses I I I
Engine oil strai ner
C -C
Carburetor
I I I
Fuel line I I I
Replace eve ry 4 years
Clutch I I I
Drive chain Clean,
lubricate and in sp ect each time th e
motor cyc le is ridden
Brakes I I I
I I I
Brake hoses
Replace every 4 years
I I I
Brake fluid Replace
every 2 years
Tires
Inspect tire pressure and damage each time
t~e motorcycle is ridden
Spoke nippl es
Inspect each time the motor cycle is ridden
Steering
I -I
Front fork
I -I
Rear suspension
I -I
Chassis bolts and nuts T T T
I : Inspect and adjust , clean, lubricate or replace as necessary
R : Replece T : Tighten C : Clean

PERIODIC MAINTENANCE AND TUNE · UP PROCEDURES 2·2
LUBRICATION POINTS
Proper lubrication is important for smooth operation and long life of each warking part of the
motorcycle.
Major lubr ication points are indi cated below.
m: Motor oil
m;Grease
NOTE:
l!J Clutch cab le __ ---,
mClu tch lever holder
m Fr on t whee lbearing mSide stand
pivot
I bearing
Throttle cable
Throttle grip holder
[i]
Swingarm pivot
bearing
mSteering stem
bearing
r!l Odometer gear box
• Before lubricating each part clean off any rusty spots and wipe off any grease, oil, dirt or grime .
• Lubricate exposed parts which are subject to rust, with motor oil or grease .

2-3 PERIODIC MAINTENANCE AND TUNE - UP PROCEDURES
MAINTENANCE AND TUNE-UP
PROCEDURES
This section describes the servicing procedures for each item
of the Periodic Maintenan ce requirements .
CYLINDER HEAD BOLTS AND NUTS,
CYLINDER NUTS, EXHAUST PIPE BOLTS AND
MUFFLER CONNECTIONS
Tighten Initial 5 Hour s and Every 30 Hours
CYLINDER HEAD AND CYLINDER
• Remove the frame covers, seat and fuel tank .
• Disconnect the spa rk plug cap and breather hose .
• Dis connec t the de- comp ocable. IRefer to page 3·2.)
• Remove the
upper side of engine mounting bolts and
cy l inder head cover. IRefer to pages 3·3 and 3-7.1
• First loosen and
retighten the four bolts CD and two nuts
® to the s pecified torque with a torqu e wrench sequen-
tially in diagonally with the engine is co ld .
Tightening torque
Bolt <D: 35 - 40 N-m 13_5 -4_0 kg-m, 25 . 5-29.0 Ib- It)
Nut @ : 23 - 27 N'm 12.3- 2.7 kg-m. 16 .5- 19 . 5Ib - It)
• After firmly tightening the cylinder head bolts and nuts .
tighten the two cyli nder nuts @ to the specified torque .
Tightening torque
Nut @ : 23 - 27 N'm 12 .3 -2.7 kg - m. 16 .5- 19 .5 Ib -ft!
• When installing the cylinder head cover. apply SUZUKI
80ND No . 12078 /121 5 to the mating suriace.(Refer to
page 3- 45 .)
EXHAUST PIPE AND MUFFLER
• Tighten the exhaust pipe bolts @). muffler connection bolt
®and muffler mounting bolts ® to the specified torque .
TIghtening torque
Bolt @ :18 - 28 N'm 11.B- 2.8 kg-m. 13 .0 - 20 .0 Ib- It)
Bolt ®: 18-28 N'm 11.8- 2.B kg- m. 13 .0 - 20.0 Ib- It!
Bolt @ :23-28 N'm 12.3-2.B kg-m. 16.5 - 20 .0 Ib- It)

PERIODIC MAINTENANCE AND TUNE · UP PROCEDURES 2·4
VALVE CLEARANCE
In sp ec t Initial 5 Hour s a nd Every 60 Ho urs
Excessive valve clearance results in valve noise and insuffi·
cient valve clearance results in valve damage and reduced
power . At the dis tances indicated above. check and adjust
the clearance to the specification.
The procedure fo r adjusti ng the valve clearance is as follows:
NOTE:
Valve clearance is to be checked when the . engine is cold.
Bach intake and exhaust valves must be checked and ad -
justed when the piston is Bt Top- Dead - Center (T .D,C.)
on the compression stroke.
• Remove the frame covers, seat, fuel tank and ignition coil.
• Remove the spark
plug and val ve inspection caps, intake
and exhaust.
NOTE:
Before adjusting the valve clearance, check or adjust the de-
compression lever clearance,
Va lv e cl ea rance sp ec ifi c ati ons
IN.: 0 .05- 0. 10 mm 10. 00 2- 0. 004 in)
EX .: 0 . 08 - 0. 13 mm 10. 003 - 0. 005 in)
• Drain engine oiL (Refer to page 2- 7.1
• Remove the T,D.C. inspection plug CD and magneto cover
cap ® on the magneto cover.
• Turn the crankshaft counterclockwise with the box
wrench to set the piston at T.O.C. on th e compression
stroke . (Turn the crankshaft until the engraved line@on
the magneto rotor is aligned with the center of hole on
the magneto cover.)
• I nsert the thickness gauge into the clearance between
the valve stem end and the adjusting screw on the r ock-
er arm .
09900 -2 0803 : Thi ck ness ga ug e
09917 - 149 10: Va lv e adjust dr iv er
• If clearance is off the specificat ion . bring it into the speci-
fied range with the special t ools .
• Securely tighten the l ock nut after adjustment is com -
pleted .
CAUTION:
Both right a nd le ft valve cl ea rances, s hould be as clo s ely
set as possible.
NOTE:
Make sure to re-c heck (he de-compression lever play , after
valve clearance adjustment is made.
• Reinstall the removed part s and add engine oil.

2·5 PERIODIC MAINTENANCE AND TUNE · UP PROCEDURES
SPARK PLUG
Inspect Every 30 Hours and Replace Every 60 Hours
The plug gap is adjust ed to 0 .8 - 0.9 mm (0 . 03 - 0. 04 in).
The gap is correc
tly adjusted wi th a thi ck ness gauge . When
carbon is deposited on the spark plug . rem ove the car bon
deposit s wi th wi re or pin. If the el ec trod es are extreme ly
worn or burnt , replace the plug. Also repla ce th e plug if it
has a broken in su l ato r, da ma ged thr ead . etc .
NGK DPR9EA-9 or NIPPON DENSO X27 EPR - U9 as listed in
the table should be used as the standard plug . H oweve r. th e
heat range of th e plug s hould be sel ec ted to meet th e re-
qu irements of speed, actual load . fu el, etc. If the plug need
to be replaced, it is recommended that the standard plug
li sted in the table be selected. Remove the plug a nd inspect
the insulator . Pr oper heat range would be indicated if it in ·
s
ulator was light brown in co lor. If it is blackened by ca r-
bon, it should be replaced by a hot type NGK OPR8EA-9 or
NIPPON DENSO X24EPR- U9 .
NOTE:
To ch eck the spark plug , f irst make sure that the fuel t ank
con ta ins unleaded g8 soli ne , and after a te st ride if th e plug
is sooty with carbon or burnt whi t e, replace it.
NOTE:
Confirm the thr ead size and reach when repl aci ng the plug .
" the reach is t
oo short, carbon will be depois t ed on th e
sc rew port io n of the plug hole and engine damage may
reslut.
NOTE:
"Rn type s park p lug is insta lled for some specifica ti on s. uR"
type spark plug hasa resistor 10 cB ted at th e cent er electrode
to
pre vent radio noise.
SPARK ARRESTER
IClean Every 30 Hours I
• R emove th e drain bolt .
• Sta
rt the engine and r ev it to blowout the accumulated
carbon part i cles .
• Stop the engine. and install the dra in bolt sec ur ely.
WARNING:
Onlyclean the spark arrester in an open area away from com -
bustible materials. Exhausted hot carbon particles can start
a fire.
0.8 - 0.9 mm
10.03-0,04 inl
NGK ~PPQN DENSQ
DPRBEA·9 X24EPR·
U9
DPR9EA·9 X21EPR· U9
~ r· ~
. .'
REMARKS
If the standa rd
plug Is ap t to
get wet , reo
pla
ce 1t with
th is hot type
plug.
Standard

PERIODIC MAINTENANCE AND TUNE - UP PROCEDURES 2-6
AIR CLEANER
Inspe ct each t ime th e motor cycle is rdden and c lean
as necessary
If the air cleaner is clogge d with dust , int ake r es ist ance will
be increased with a resulta nt decrease in powe r output and
an in cre ase in fu el consumpt ion.
Check a nd clean th e element in th e following manner:
• Remove the l eft frame cover.
• R emove the air cleaner case cove r.
• Remove the element.
• Sepa rat e th e polyurethan f oam element CD fr om th e e l e ~
me nt frame @ .
• Fill a washi ng pan of a proper size wi th nonflammab le
cleaning sol vent . Immerse the elem ent in th e cleaning sol-
vent a nd wash it cl ea n.
• Squeeze
th e cleani ng solvent of th e washed element by
pressing it between t he palms of bo th hands .
• I mme rse the element in motor oil, and squeeze th e oil out
of the element leavi ng it slightly we t wi th oil.
NOTE:
Do not t wist or wring th e element be cause it will t ear or t he
in d ividual cells of t he element will be damaged.
CAUTION:
In spect the element carefully for rips. torn seams, etc . If any
damage is noted . replace the element .
• Reinstall
the cleaned or new cleaner element in the
reverse order of removal.
DE-COMPRESSION LEVER
Ins pect Initial 5 Hour s and Every 30 Hours
Incorr ect adjus tm ent of th e lever clearance may res ult in
s
tarting difficulties or engine damage. Ch ec k th e lever clear-
ence and if necessary, adjust as foll ows :
• A
djus t the val ve clearance. (Refer to page 2-4 .)
• Loosen both l ock nut s @ on th e cable adjuster @.
• L ocate th e adjuster @ to pr ov ide the specified lever clear-
ance ®as sh own in photograph .
• Tig ht en b ot h l ock nuts @.
De- compression l ever clearance ®: 1- 2 mm
(0 _ 04 - 0 _ 08 inl
Nonflammable cl ea ni ng
solvent ~ !
lJLJ ,.
~ , i'---- ..
,'
,
SAE
1 QW /40
OIL

2-7 PERIODIC MAINTENANCE AND TUNE - UP PROCEDURES
ENGINE OIL, OIL FILTER AND OIL STRAINER
Replace (Change) oil and oil filter Initial 5 Hours and
Every 60 Hours
Clean oil strainer Initial 5 Hours and Every 60 Hours
Th e oil sho uld be cha ng ed while the engine is h ot .Oil filter
replaceme nt at th e above in t erva ls should be done together
with engine oil change .
• Amove the engine under cover .
• Keep the motorcycle upr ight. supported by jack or bl ock.
• Pl ace a"n oil pan under the frame head pipe and th e engine.
• Rmove th e engine oil drain plug s ( CD and 0 1 and oil filler
ca p @ to drain engine oi l.
• R emove the oil filter cap @ by removing th e thr ee bolt s.
• Remove the old filter ®. and install th e new one.
• Replace th e filter cap @) and tight en the bo lt s secure l y.
NOTE:
Before installing t he oil filter and filter cap . check to be sure
that the spring ® and new O-rings ( <2) and @) are installed
correctly.
• Remove the oil strainer ®.
• Clean the oil s tr ainer ® at th e above intervals.
• Tighten the oil st rainer ® to the specif ied torque.
Tightening torque : 25 - 30 N·m
12 . 5-3 .0 kg-m. 18 .0 - 21-5 Ib -ftl
• Tighten the oil drain plugs KD and 0 )sec urely . and add
fresh oil through the oil filler. The engine will hold about
1 900 ml of oil.
Use API classifi cat i on of SE or SF oil with SAE 1 0W / 40
vis cosity .
• Install the filler cap @.
• Sta rt up the engine and allow it to run f or 3 minutes at
idling speed.
• Stop th e e ng ine w it h th e engine stop switch and wa it
one minute . then check th e oil level by rem ovi ng the oil
level gauge @. If the level is be l ow mark " F" . add oil
to that level.
NECESSARY AMOUNT OF ENGINE OIL
Oil change : 1 700 ml 11 .8/1_5 US/lmp qtl
Filter change : 1 900 ml (2.0/ 1.7 US/ Imp qt)
Overhaul engine: 2100 ml (2.2 /1.8 US/ Imp qt)
(

PERIODIC MAINTENANCE AND TUNE · UP PROCEDURES 2·8
CARBURETOR
Inspect Initial 5 Hours and Every 30 Hours
THROTTLE CABLE ADJUSTMENT
A twin throttle cable system is used in thi s motor cyc le. Ca ·
ble CD is for pulling and cable @ is f or r eturning. To adjust
the cable play ,ad ju st the returning cable first and then ad-
just the pulling cable.
Returning Cable Play
The returning cable adjuster should have 2- 3 mm
(0.08 - 0. 12 in) of clearance as shown in the illustration .
If the adjustment is neces sa ry . carry out the proce dure
below :
• Loosen the l ock nut ® .
• Turn adjuster ® to obtain the clearance @ of 2 -3 mm
10 . 08 - 0. 12 inl.
• Tighten the lock nut @ securely .
Pulling Cable Play
The pulling cable play @ s hould be 0.5- 1.0 mm
(0.02 - 0 . 04 in). If the adjustment is necessary, ca rry out
the procedure below :
• Turn the handlebar all the way to the le ft .
• loos en lock nut @.
• Turn adjuster ® to obtain a cable play of 0.5 - 1.0 mm
10.02- 0. 04 in).
• Tighten lock nut ® securely.
• Make sure that th e clearance of ©is less than 1.0 mm
(0 . 04 in) when th e thrott le grip is fully opened .
WARNING :
After the adjustment is completed. check that handlebar
movement does not raise the engine idle speed and that the
throttle grip returns smoothly and automatically .
AI OLE RPM{Idling adjustmentl
NOTE:
Make this adjustment when the engine is hot .
• Start up the engine and set it s speed at anywhe re be·
tween 1 300 and 1 500 rl min by turning the throttle s top
screw 0.
• Turn in or out the pilot screw ® within 112 turn from the
standard
se tting . and se t it whe n the engine speed is at
the highest possible level.
•
Aft er thi s adjustment . recheck the idling speed and ad·
just to between 1 300 and 1 500 rl min with throttl e s top
screw if necessary.
•
.'

2·9
FUEL LINE
In sp ec t Initi al 5 Hour s a nd Eve ry 30 Hour s
Repl
ace Ev ery 4 years
Inspect the fuel line for damage and fuel leakage .
If any defects are found. the fuel line must be replaced .
CLUTCH
Insp ec t Initial 5 Ho ur s a nd Ev ery 30 Ho ur s
• Loosen the lock nut <D and turn the adjuster ® fully in.
• Loosen the cable lock nut @ and adjust the play of the
cable with the adjuster @ until play of the clutch lever
isl0 - 15mm.
Clutch l ever play ®: 10 - 15 mm (O.4 - 0. 6 in)
• Tighten the lock nuts ((D and @ ).
NOTE:
Minor adjustment can be made by the adjuster @ after
loosening the lock nut <D .A t the same intervals . lubricate
the clutch cable with motor oil.
DRIVE CHAIN
Cl ea n. lub ri ca te a nd insp ec t eac h time th e
mo tor cyc le is red de n
Visually inspect the drive chain for the listed below possi·
ble defects . (Lift the rear wheel and place a jack or block
under the engine, and turn the rear whee l sl owly by hand
with the transmission in NEUTRAL.
• Loose
pins
.. Damaged rollers
I' Dry or rusted links
I' Kinked or binding links
I' Excessive wear
.. Missing Q·rings
If any defec ts are found , the drive chain must be replaced.
C HE CKING
• Remove the cotter pin ® (For U.S .A. and Canada).
• Loosen the axle nut @.
• Tension the drive chain fully by turning the right and left
chain adjusters 0.
• Count out 21 pins (20 pitches) on the chain and meas·
ure the distance between the two points . If the dis tance
exceeds following limit , the chain must be replaced.
Service Lim it : 31 9. 4 mm (12.57 in)