Yamaha XS750-2D Service Manual

SPECIFICAT IONS

A.GENERALSPECIFICATIONS

Basiccolor
Dimensions:

Overall length
OveralI width
Overall height
Seat

height
Wheelbase
Minimumgroundclearance
Caster

(steeringheadangle)

TraiI

Weight:

Net

Engine:

Type
Borexstrokexcylinders

Displacement
Compressionratio

Compressionpressure(warmengine)

Lu b r ication

:

Lubricationsystem
Deliverypump type

CrystalSilver

2180mm(85.8in.)
835mm(32.9 in.)

1150mm(45.3 in.)
810mm(31.9in.)
1465mm(57.7in.)

145mm(5.7in.)

27°

110mm(4.3 in.)

229kg(505Ibs.)

________~~

D.O.H.C., air-coo led, triple

68mmx68.6mmx3
747cc

8.5:1
142Ibsin²(±14Ibsin²)

Pressurelubricated, wet sump
Trocoid

Carburetion:

Manufacture

Type,I.D.No.,Quantity

Ratedventuri

size

Airfilter

Ignition:

Type

Sparkplug

Charging

Type

Manufacture,I.D.No.
Maximumoutput
Batterytype
Batterydimensions
Regulator

Rectifier

Starting

Mikuni
BS34,constantvelocity,1J701,3pcs.
34mm

Dryfoamrubber

Battery/coi

I

NGKBP-7ES,ChampionN-7Y

Three-phase,regulatedalternator
HitachiLD120-02

14.5Volt/l8amp
12volt14amp-hour

134x166x89mm

Hitachi TL1Z-80

Stanley DE-4404,Silicon,fullwave

Transmissioncoupledkick

MitsubaElectricSM-224C

Primarydrive

Type

Teeth,ratio

Clutch

Hy-Vo silentchain

45/271.666

Wet,

multipledisc.

Transmission:

Teeth,ratio,overall1st

SecondaryDrive:

Transmission0utput

Type,teeth,ratio

Middlegear

case

Type, teeth, ratio

Finalgearcase

Type, teeth, ratio

Chassis:

Frame

Suspension:

Front
Rear

(type,

(type,

travel)
travel)

Tires:

Front
Rear

Brakes:

Front

Rear
Fueltank
Wheels:

Front

Rear

:

2nd
3rd
4th
5th

Constantmesh,5-speed,drumshifter
32/132.46113.285
27/171.5888.636
26/20 1.300 7.069

11.0955.955

22/23 0.956 5.201

Shaftdrive

Spurgear,34/32,1.063

Bevelgear,19/18,1.056

Bevelgear,32/11,2.909

Tubularsteeldoublecradle

Telescopicfork,175mm (6.9 in.)
Swingarm,75mm(3.0in.)

3.25 H 19Bridgestone

4.00H18Bridgestone

Dualhydraulicdisc

Singlehydraulicdisc

USgal.)Regularleadedorunleaded

1.85x19

2.15x18

Cast
Cast

Aluminum
Aluminum

B.

MAINTENANCESPECIFICATIONS

1.

Engine

EngineOilCapacity

Oil

andfilterchange

Oilchange

R

ecommended Iubrican

If

temperaturedoesnotgobelow

t

:

Iftemperaturedoesnotgoabove

SAE

SAE

(3.7
(3.4USqt.)
(3.0USqt.)

SE

motoroil

SE

motoroil

Middlegear

case

capacity:

FinalGearcasecapacity
Recommended Iu b r ican

t

Iftemperaturedoesnotgobelow
5°C (40°F)

Iftemperaturedoesnotgoabove

15°C(60°F)

A

I I

weather

375cc(13 oz.)

300cc

SAE90Hypoid

SAE80Hypoidgearoil,

(1

00

oz.)

gear

oil,GL-4

GL-4

SAE80W90Hypoidgearoil,GL-4

Crankingpressure

(at

sea

Maximum difference betweencylinders

Camshafts

I

Camshaftbearingsurfacediameter 24.97~24.98mm (0.9830~0.9835 in.)
Camshaft-to-capclearance

Standard

Maximum

Camshaftrunoutlimit

Valves

level)

:

10 ± 1kg/cm²(142 ±14psi)

1.0kg/cm²(14psi)

8.018mmm

A

Exhaust

B

28.285 ±0.05mm28.13mm

C

36.303 ± 0.05mm36.15mm

.020~.054mm(.0008~.002in.)
.160mm(.006in.)

0.1mm(.004in)

I

INNER

Wear

-------------

OUTER

Iim

it

I

ALLOWABLETILT
FROMVERTICAL

I

OUTER

INTAKE EXHAUST

DIRECTIONOFWINDINGS

(TOPTOBOTTOM)

I

Valvestemrun-outmaximum
Valve

seat

Freelength

Springrate(kg/mm)

Installedlength

(valve closed)

Installedpressure

(valve closed)

OUTER

Compressedlength
(valveopen)23.0mm

Wire diameter

Numberofwindings

Winding

widthstandard/maximum

O.D.

INTAKE/EXHAUST

35.6mm
K11.84

K22.36

INTAKE/EXHAUST

39.9mm
K13.32

K24.18

34.5mm31.5mm

1

7.5 ± 0.75kg 17.5 ± 1.2kg

26.0mm

2.8mm

7.75
15+0.3mm

0

I

~

3.9mm

6.4

21.6

1

0

-

0.3mm

.03mm(.0012in.)

1.3mm(.050in.)/2.0mm(.080in.)

C

I

ea

rance

(Coldengine)

0.1

6~0.20mm

"B"

"A"

headdiameter

I

"B"

facewidth2.26 ± 0.57mm

"C"

seat

width

"D" marginthickness

Stemdiameter
Guide diameter (I.D.)

I

Stem-to-guideclearance
EXHAUST

CIearance
(Coldengine)0.21 ~0.25mm

"A"

headdiameter

(O.D.)

36+0.2

1.3 ±0.15mm

1.2±0.2mm

7+.010mm

-.025mm

7+.019mm

-.010mm

I

0.020~0.041mm

31+0.2mm

I

CylinderandPiston

Cylinder material
Cylinder liner
Standardboresizehtandard

maximum

Cylindertaperlimit

Cylinderout-of-roundlimit
Pistonclearancehtandard

maximum

"B"

facewidth

"C"

seat

width

"D" margin thickness

Stemdiameter (O.D.)

Guide diameter (I.D.)

St

em

-t

o

-g

uid

e

clearance

Aluminum

Pressed

68.00~68.02mm/(2.677~2.678in.)

68.10mm(2.681)

0.05mm(.002in.)

0.01mm(.0004in.)

0.050~0.055mm/(.0020~.0022 in.)

0.1mm(.004in.)

in;

special

2.26 ± 0.57mm

1.3 ± 0.15mm

1.2± 0.2mm

7+.025mm

-.040m m

7+.019mm

0.035~0.059mm

castiron

PistonRings

Design
Endgap(installed)

Side clearance

Oil

-0.4mm-0.4mm0.2~0.9mm

0.04-0.08mm0.03-0.07mm

CrankshaftandConnectingRods:

Mainbearingoilclearance
Rod bearing oilclearance
Mainjournalrun-out(maximun)

Oil

Pump

Housing-to-outerrotorclearance

Outerrotor-to-inner rotor clearance

Clutch

Frictionplatethicknessstandard

minimum

Clutchplatewarpmaximum

0.022~0.044mm(.0009~.0017in.)

0.032~0.054mm(.0013~.0021in.)

0.03mm(.0012in.)

,090~.015mm(.0035~.0059in.)
.03 ~.09mm(.0011~.0035in.)

3.0mm(0.12in.)

2.8mm(0.11in.)

0.05mm(.002in)

Clutchspring length standard

minimum

Clutchpushrodrun-outmaximum
Clutchleverfreeplay(endoflever)

Transmissionshaftrun-outmaximum

Middle gear

2.

Carburetion

case

lash

I

42.8mm(1.685in.)

41.5mm(1.634in.)

0.4mm(.016in.)
13~26mm(0.5~1.0in)

.08mm(.001in.)

0.1 ~0.2mm(.004~.008in.)

Manufacturer
Model,

I.D.No.

Mainjet
Needlejet

Pilot jet
Starterjet
Jetneedles/Clip position

Mikuni
BS34,1J701

No.

145

Y-2

No.

17.5

No.

45

4H11/3

Floatlevel

Pilotscrew
Airjet,Main
Airjet, Pilot

Throttlevalve
Inletvalve

size

Engineidlespeed

26.5 ±2.5mm(fromgasketsurf
2¼turns

1

.0mm

1.6mm

No. 140

2.0mm
1050 ~ 1150r.p.m.

3.

Chassis

WheelsandTires

Rimrun-out,vertical
Rim run-out, horizontal

Tirepressure,front,normalriding

Highspeedorwithpassenger

Tirepressure,rear,normalriding

Highspeedorwithpassenger

Brakes

Recommendedfluid

Minimum boiling point

Padthicknesswearlimit
Brakediscmaximum deflection
Brakediscminimumthickness
Frontbrake freeplay (endoflever)
Rearbrake freeplay (endofpedal)

Frontforks

Spring(upper)free length

Spring(lower)freelength

Springrate

Forkoilcapacity(each side)

preload length

preload length

(0 ~100
(100~175mmtravel)

mmtravel)

2.0mm(.080in.)
l.0mm(.040in.)

1.8(26p.s.i.)

2.0kg/cm2(28p.s.i.)

2.0kg/cm2(28p.s.i.)

2.3kg/cm2(33p.s.i.)

DOTNo.3
240°C(464°F)

5.5mm(0.18in.)

0.15mm(.006in.)

6.5mm(0.26in.)

5.0~10.0mm(0.2~0.4in.)

5.0~10.0mm(0.2~0.4in.)

55.8mm(2.2in.)

50.8mm(2.0in.)

448.3mm(17.65in.)

423.3mm(16.67in.)

0.5kg/mm(28Ibs/in.)

0.6kg/mm(33.6Ibs./in.)

170cc(5.75USfl. oz.)

~~

Rearshock absorbers

Spring free length
Spring preload length
Springrate(0~45mmtravel)

(45~75mmtravel)

Ignition timing retarded

advanced

advancestarts

Sparkplug

Electrodegap

Sparkplugcapresistance
Contactpointgap

Spring tension

Condensercapacity

Insulationresistance

253mm(9.95in.)
228mm(9.0 in.)

1.9kg/mm(106Ibs./in.)

2.6kg/mm(145Ibs./in.)

10° @1100rpm

38.5° ± 1.5°@ 2,900 rpm
1550 + 200rpm

0

NGKBP-7ESorChampionN-7Y

0.7~0.8mm(.028~.032in)

I

5.0 K ohms

0.3~0.4mm(.012 ~.016in)
750 ±1 00g(26.5 ± 3.5oz)

0.22µF ± 10%

10 M ohms ormore

Ignitioncoiltype

Sparkgap6V

12V
Primaryresistance(20°C)
Secondaryresistance

(20°C)

H

itachiCM11-

6mm @

7mm@ 5,000 rpm

4.0 ± 0.4 ohms

11.0 ± 1.1K ohms

52A

100 rpm

~~~

Startermotor type

Armaturecoilresistance(2O°C)

Fieldcoilresistance(2O°C)

Brushlengthstandard

minimum

Brush spring pressure

Armaturemicaundercut

Batterytype

Chargingrate

Generator

type

Noloadvoltage

Field(inner) coil resistance(20°C)

Stator (outer) coil resistance (20°C)

Regulatortype

Reg

ulatedvo

I

t

age

Core gap

Yokegap

Point

gap

Mitsuba SM-224C

0.007 ohms

0.01 ohms

12.5mm(0.5in)

5.5mm(0.22in)
620 ± 60g (22.0 ± 2.0 oz)

0.5 ~ 0.8mm(0.02 ~ 0.03in)
YuasaYB14L

1.4ampsfor10hours

HitachiLd120-02

14.5 ± 0.5V

4.04 ±0.4 ohms

0.48 ±0.05 ohms

HitachiTLIZ-80

14.5 ±0.5V

0.6 ~ 1.0mm (.024 ~.040 in)

0.9mm(.035in)

0.3 ~ 0.4mm(.012 ~.016in)

Starterrelayswitch

Cut-involtage

Windingresistance(20°C)

Lighting

Headlight

Ta

i

IIigh t/stopIight

Licenselight
FlasherIight
Flasherpilotlight

Meter Iights

Highbeamindicator light

Oilpressurewarninglight
Neutrallight

HitachiA104-70

6.5 V

3.5 ohms

Sealed beam 12V50/40W

12V8/27W(twobulbs)
12v 8W
12V27W(fourbulbs)
12V3.4W(twobulbs)
12V3.4W(twobulbs)
12v3.4w
12v3.4w
12v3.4w

C.

I

I

Torque

Engine

Sparkplug
Camcapnut

Starterclutchbolt
Shiftcamlocatingbolt
Detentassembly
Transmission bearing caps
Crankcasebolts8mm

Clutch holding nut
Clutchspringscrews
Middle gear case mounting screws
Rotorholdingbolt
Bearinghousingbolt

Oil

Oil pump drive gear nut
Crankshaftturningnut
Cylinderhead8mm

Cylinderholdingnuts
Camshaftcapnuts

Enginemountingbolts10mm

Specifications

Rodcap

pipe

1 0mm

unionbolt

1 0mm

12mm

Engineoildrain plug

Oil

filtermountingbolt

Middlegeardrain plug

Chassis

Frontaxlenut

Frontaxleholdernuts

Rearaxlenut

Rearaxlepinchbolt

Brakes

Calipersupportbolt

Calipermountingbolt

Brakehoseunionbolt

Discmountingbolt

Frontforkpinchbolt

Steeringstemtopbolt
Swing arm pivotlocknut

Rearshock absorber nut

1.5 ~ 2.5m-kg(11.0 ~18.0ft-lbs.)

0.8 ~ 1.Om-kg(6.0 ~ 7.0ft-lbs.)

3.8m-kg(27ft-lbs.)

2.8 ~ 3.2m-kg(20 ~ 23ft-lbs.)

1.3 ~ 2.1m-kg(9 ~ 15ft-lbs.)

4.0 ~ 4.5m-kg(29 ~ 32ft-lbs.)

1.8 ~ 2.2m-kg(13 ~ 16ft-lbs.)

2.0rn-kg(14 ft-lbs.)

3.7m-kg(27 ft-lbs.)
8 m-kg (58ft-lbs)

0.8 ~ 1.Om-kg(6.0 ~ 7.0ft-lbs.)

2.0 ~ 2.5m-kg(14 ~ 18ft-lbs.)

3.0 ~

2.0 ~

2.0 ~ 2.2m-kg(14 ~ 16ft-lbs.)

8.0~12.0m-kg(58 ~ 87ft-lbs.)

1.5 ~ 2.9m-kg(11 ~ 21ft-lbs.)

2.0m-kg(14ft-lbs.)

3.5m-kg(25ft-lbs.)

2.0m-kg(14ft-lbs.)

1.Om-kg(7ft-lbs.)

5.0 ~ 6.0m-kg(36 ~ 43ft-lbs.)

I

1

8.0 ~ 11.0m-kg(58 ~ 80ft-lbs.)

3.9 ~ 4.7m-kg(28 ~ 34ft-lbs.)

3.0 ~ 3.4m-kg(22 ~ 25ft-lbs.)

3.9 ~ 4.7m-kg(28 ~ 34ft-lbs.)

7.0 ~ 10.0m-kg(50 ~ 72ft-lbs.)

1.3 ~ 2.3m-kg(9 ~ 17ft-lbs.)

12.0 ~ 18.0m-kg(87 ~ 130ft-lbs.)

0.45 ~ 0.75m-kg(3.0 ~ 5.0ft-lbs.)

1.5 ~ 2.0m-kg(11 ~ 15ft-lbs.)

4.5 ~ 5.0m-kg(28 ~ 35ft-lbs.)

2.3 ~ 2.8m-kg(16 ~ 20ft-lbs.)

1.7 ~ 2.2m-kg(12 ~ 16ft-lbs.)

1.3 ~ 2.3m-kg(9 ~ 17ft-lbs.)

6.6 ~ 10.5m-kg(48 ~ 76ft-lbs.)

8.0 ~ 10.0m-kg(58 ~ 72ft-lbs.)

2.3 ~ 3.7m-kg(20 ~ 27ft-lbs.)

4.0m-kg(22 ~ 29ft-lbs.)

2.4m-kg(14 ~ 17ft-lbs.)

500 - 600

Componentsshould be room temperature.

SPECIAL

tool

TOOLS

ValveguideremoverClutchholdingtool

Valve guide installer

Valvespringcompressor

Clutch plate installation tool

Clutch lock

nut

Final drive gearholdingtool

Middle

wrenchDamperspecial

and

finalgearholding

tool

Valveseatcutterset

Tappetadjustingtool

Vacuumgauge

Camchain cutter

Slide hammer

Gear lash measurementtool

(middlegear)

Rotorpuller

Rotor holding tool

Gear

lash

measurementtool

(finalgear)

d.Turnpetcocksto"prime"position.

or out

e.

Start

motorcycleandallowittowarmupfor

2-3

minutes.The warm-upiscompletewhen

enginerespondsnormallytothrettleopening.

f.

Adjustdampingvalveoneachvacuumgauge

untiltheneedleflutters only slightly. The
gaugeneedlesmust respond quicklytorapid

openingofthe throttle.

g.Eachgaugewillindicatethesamereadingif

thecarburetorsaresynchronized.Theleftand
rightcarburetors

centercarburetor,which

screw.Turnthe
screwuntilthegaugereadingisthesame
forthecentercarburetor.Repeatfortheright

carburetor.

are

tobe synchronized tothe

has

nosynchronizing

left

carburetorsynchronizing

as

a.

Theenginemustbewarmedupbeforesetting

idlespeed.

b.Set engine idlespeedbyturningthethrottle

stopscrewin(toincreaseenginespeed)
(todecreasespeed).

StandardIdle

1,050

-

1,1

RPM

50rpm

SYNCHRONIZING

3.

-_-

Idle

speed

NOTE:

beforesetting

adjustment

throttlestopscrew.

Carburetorsmustbesynchronized

SCREWS

adjustment.

final

idlespeed.Theidlespeed

is

madebyturning only one

B.

AirFilter

1.

Removal

a.

Lifttheseatandremovethe

byremovingthepanheadscrews

air

filtercasecap

(2).

b.

the two.

Pullouttheelement.

2.

Cleaningmethod

a.

Tapthe element lightlytoremovemostofthe
dustanddirt;thenblowouttheremainingdirt
withcompressed
ofthe element. Ifelementisdamaged,replace.

air

through the innersurface

C.

Engine/TransmissionOil

1.

Oillevel measurement

a.

Tocheckthe

severalminutes.Stoptheengine.Withthe
enginestopped,screwthedipstickcompletely
outandthen

NOTE:

thedipstick,
onthecasethreads.
stopped and themachineispositionedstraight

upandonbothwheels.

Whencheckingengineoillevelwith

level,

warmtheengineupfor

rest

thestickinthehole.

let

theunscreweddipstick

Be

suretheengine

rest

is

b.Reassemblebyreversingtheremovalpro

cedure.Checkwhethertheelementisseated
completelyagainstthecase.

c.

The

air

filterelement should becleanedonce

a

monthorevery1,600km

shouldbecleanedmoreoftenifthemachine

is

operatedinextremely dusty areas.

(1,000

miles).

b.ThedipstickhasaMinimumandaMaximum

mark.Theoil

If

the

levelislow,

totheproperlevel.

2.

Engine/Transmissionoilandoilfilterreplace
ment

a.

Start

theengine.Allowittowarmupfor

minutes.Stop the engine.

b.

Placeanoil

theoil

c.Removethedrainpluganddraintheoil.

-

filler

level

should be between

add

sufficientoilto

pan under theengineandremove

cap.

raise

it

-

It

without

cessiveoilcontamination

may

theaircleanerelement

result.

installed.

and

enginewear

Ex

-

d.Removetheoil filter boltand

level

end marked

case.

e.

Reinstall

e.

Reinstall

f.Installtheoilfilterelement andcover. Tighten

theoil filter bolt.

thedrain plug (makesureitistight).

thedrain plug (makesureitistight).

4.0 ~4.5m-kg(28.9-32.5ft-lb)

filter

element.

h.Afterreplacementofengineoil, and/or oil

filter,

leakage.Theoilpressureindicatorlightshould
gooff

CAUTION:
remains on, immediatelystop

Refertolubrication information inSec.

D.

MiddleGear/FinalGear

be sure tochecktheoilpressureandoil

after

theengineisstarted.

If

the"Oil"indicatorlight

the

Oil

engine.

3-5

NOTE: Make surethe
properly.

g.

Add oil through the dipstickhole.

"

0'

ringispositioned

1.

Oillevel measurement

a.Placethemachineonalevelsurfaceandplace

it

onthecenterstand.Theengineshouldbe

cool

(at

atmospherictemperature).Allow

minutesfor oil todraintobottomofcases.

b. Remove theoil

withlevelgauge(fromtoolkit)
The correct oillevelisbetweenthetwomarks

oneachendof

gaugemarked"REAR"formeasuringthe

rear

(final)gearcase.

NOTE:Middlegearandfinalgearoilcanbe
checkedwithsamelevelgauge,whichisin
theownerstool kit.

filler

cap.Checktheoil

as

shown.

the

level

gauge.

Use

measuringthemiddlegear

Use

the

endof

2

Oilquantity:PeriodicOilChange

2.8

liter

(3USqt)

Withoilfilterchange:

3.2

liter

(3.4USqt)

Recommendedoil:exceptincoldweather

Yamalube4-cycleorSAE20W40

(see

page

8)

"SE"

d.Fillthe

gear

case(s)uptospecifiedlevel.

CAUTION:

Takecarenottoallowforeign
materialtoenterthemiddleand/orfinal
aear case.

2.

Gear

oilreplacement

a.

Placeanoilpan under
themiddle

b.

Removethe middle and/orfinal

gear

and under the final

the

transmissionfor

gear

gear

oil

case.

filler

cap(s)andthedrainplug(s),anddrainthe

nottoallowforeignmaterialtoenterthe
middleandlor

the

gearoiltocontactthetire

final

gear case.

Do

and

notallow

wheel.

c.Reinstallthe middle and/orfinaldrainplug(s).

oil.

OilCapacity:

Middlegear case:
Final

gear

Recommendedoil:

e.

Reinstallthe filler cap(s)securely.

NOTE:

is

normallynotnecessarytochangemiddle
andfinal
indicatedserviceintervalof

E.

Clutch Adjustment

375cc(12.7

case:

300cc

(see

Afterinitial

gear

oilmorefrequently than the

page

250

US.

fl

(10.0

U.S.

fl

8)

mileoilchange,

6,000

02)

02)

it

miles.

Thismodelhasaclutchcablelength adjustor and
clutchmechanismadjustor.Thecablelengthadjustor5

are

usedto

take

upslackfromcablestretchandto
providesufficientfreeplayforproperclutchoperation
under various operating conditions. The clutchmech

anismadjustorisusedtoprovidethecorrect amount

ofclutch"throw"forproperdisengagement.Normal
ly,oncethemechanismisproperlyadjusted,theonly
adjustment required ismaintenanceoffreeplay

the clutch handle

1.

Freeplayadjustment

lever.

at

Looseneither the handle leveradjustorlock

nutor the cablelength adjustor locknut.

Next,turnthe length adjustor eitherinorout

untilproper

lever

freeplayisachieved.

a

-

-

cover.

2.

nut

Mechanismadjustment
Thesecondadjustmentislocatedbehindthe

adjusting cover. Removing thecoverwill
exposethe adjusting
Loosenthelocknutandrotatethe
in until itlightly

rodthatworkswiththe
theclutch.Backthesetscrewout ¼ turnand
tightenthelocknut. This adjustmentmustbe
checkedbecauseheatandclutchwearwill
affectthis
causeimproperclutchoperation.Recheck
clutchcableadjustment
adjusting.

free

set

screwandlocknut.

set

seats

againstaclutchpush

set

screwtooperate

play,possibly enough to

at

handlebarafter

screw

1.

Removethebreakercover

2.

Removethecamchain tensioner

Loosenthetensioner stopper boltlock
andthenloosenthestopperbolt.

F.

CamChainAdjustment

Thecamchain becomesstretched with

improper

thecamchain tensioner must be adjusted regularly.

valve

timingandenginenoise.Topreventthis

use,

resultingin

4.

Slowlyrotate the crankshaftcounterclockwise
severalturns.Whenthetensionergetsdeepest

intothe tensioner holder,tighten the stopper
boltandsecureitwiththelocknut.

S

5.

Adjustment

appropriate chart

Reinstall the chain tensionercapandthecon
tactbreakercover.

G.

ValveClearanceAdjustment

-

Exhaustvalve clearance (cold)

0.21-0.25mm(.008 -.010")

Intakevalve clearance (cold)

0.16-0.20mm(.006-,008")

NOTE:

Valveclearancemustbemeasuredwith

theengineatroomtemperature.

1.

Remove

gas

tank.

2.Removeairscooponcylinderhead

3.

Removecylinderheadcoverandbreakerpoint
cover.Careshouldbetaken

to

notscratchor

damagegasketsealing surfaces.

4.

Turncrankshaftwith nut on

left

endofcrank­shafttoturncams.The proper positionofthe
camwhenmeasuring

valve

clearanceiswith

thecamlobedirectlyoppositethevalvelifter.

Adjustment
Valveclearanceisadjustedbyreplacingtheadjusting

padonthetopofthevalvelifter.Adjustingpadsare
availablein25thicknessesrangingfrom

No.

200
(2.00mm)toNo.320(3.20mm)instepsof0.05mm.
Thethicknessofeachpadismarkedonthepadface
thatcontactsthe valve lifter(notthe cam).
ofvalve clearance isaccomplishedasfollows:

1.Determinevalve clearance

(feeler

gauge

measurement.

2.

Removeadjustingpadandnotenumber.

3. Select properpadfrom
(intakeorexhaustchart).

4.

Installnewpadandcheckinstalledclearance.

Procedure

5.

Insertafeelergaugebetweenthevalvelifter

andthecamheel.

1.

Measurevalveclearance.Ifclearanceisin
correct,recordthemeasuredamountof
clearance.This must bemeasuredcarefully.

2.

Thereisa

slotinthevalve lifter. This slot must
bepositionedoppositethebladeofthetappet
adjustingtoolbeforethetool

3.

Turnthecamuntilthelobefullydepresses

is

installed.

thevalvelifterand opens thevalve.Install the
tappetadjustingtool

as

showntoholdthe

lifterinthisdepressedposition.

AD

JUST

I

NG

TOOL,

CYLINDER

-

PADREMOVAL
SLOT

NOTE:The tappet adjustingtoolisfastened

to

thecylinderheadusingone

suchasoneusedto

install

(1)

allenscrew

thecylinderhead

cover.Makesurethat the tool contactsthe

lifteronly,

and

not

the

pad.

EXAMPLE:Exhaustvalve,installed

No. 250

(readdown)

Measuredclearance:0.32mm

(readacross)

Newpad number: No.

(intersectionofdown&across)

pad:

260

CAUTION:Ifthecamlobetouchesthetappet
adjusting
cylinderhead.

tool,

thestressmayfracturethe

DO

NOTALLOW THE CAM
TOCONTACTTHETAPPETADJUSTING
TOOL.

4.

Carefullyrotatethecamsothat the padcan

be removed. Toavoid cam touchingadjusting
tool,turncamsasfollows: (view fromleft
sideofmachine)

Intake: Carefully rotate CLOCKWISE.
Exhaust: Carefully rotateCOUNTERCLOCK

WISE.

5.

Removethepadfromthe lifter. Thereisa
slotinthelifter.Useasmallscrewdriveror
otherblade
pad.

Notethe number

and

a

magneticrodtoremovethe

on

the

pad.

NOTE:Thenewpad number

is

to

aguideonly.Verifythecorrectnessofthis
choiceinthefollowingsteps).

7.

Installthenew

pad

withthenumberdown.

8.

Removetappetadjustingtool.

9.

Turncrankshaft

tions.

10.

Checkvalve clearance (step3).Ifclearance

This

incorrect,repeatpreceding

-

clearanceisobtained.

11.

Inspectheadcovergasket.

pad

in

to

rotatecamseveralrota

willsetthe

thelifter.Installthe

pad

in

steps

until

If

bentortorn,

replacegasket.

12.

Reinstallremovedpartsinreverseorder.

H.

CompressionPressureMeasurement

Insufficientcompressionpressurewillresultinper

formance

loss

and may indicate leaking valvesorworn

ordamaged rings.

be usedas

the

lifter.

proper

-

is

-

6.

Proper

pad

selectionismadeasfollows:

(Useappropriate chart forexhaustorintake

valves.)

a.Findnumberoforiginal (installed)

pad

num

beronchart.Readdownonchart.

b.

Findmeasured valve clearance (fromstep

onchart.Readacross.

c.Attheintersectionofinstalledpadnumber

(down)andmeasuredclearance(across)isa

new

pad

number.

1)

-

Procedure

1.

Makesurevalveclearanceiscorrect.

2.

Warmupengine 2-3 minutes.Stopengine.

3.

Removespark plugs.

4.

Installcompression check gauge.

Intake

CLEARANCE

...

,

.............. .

.....

.

,

.

i..

:

.

I

...........

Exhaust

5.

Turnoverenginewithkickorelectric

(makesurebattery
throttlewide open untilpressureindicatedon

thegaugedoesnotincreasefurther.

Standard:I0kg/cm²(142psi)

Minimum:9kg/cm²(128psi)
Maximum: 11kg/cm²(156psi)

.

Ifpressureistoolow,squirtafew drops ofoil

intothe cylinder beingmeasured.Measure
compressionagain.Ifthereisa
thanbefore(withoutoil),thepistonrings

maybewornordamaged.Ifthepressure
mains
eitherorboththe
the

Checkeachcylinder.
shouldnotvarymorethan1kg/cm²(14psi)
fromonecylindertoanyothercylinder.

the

cause.

same

is

fullycharged)withsolvent.

after

measuringwith

ringsand

Compression pressure

higherreading

valves

starter

re

the

oil,

maybe

2.Removethedraincoverandclean

-

B.

Fuel Petcock

Ifthefuel petcock isleakingorexcessivelycontami

nated,itshouldberemovedfrom the fuel tank

inspected.

1.Removefueltankandpositionitso
will not spillwhenthepetcockisremoved.

Disassembly

it

with

and

thatfuel

-

2-4

CHASSIS 4.

A. FuelPetcockCleaning

1.

Turn the petcocklevertothe

"

RES

"

position.Removethe fuel pipe.

"ON"

or

2. Remove petcockandinspectfilterscreen.
Replacefilterifseriously contaminated.

3. Remove4screwsonfrontandrear

andremoveplate,gaskets,leveranddiaphragm.

Inspect
are
damaged,or the petcockbodygasketsurfaces
scratchedorcorroded,thepetcockassembly
mustbereplaced.Ifthere
toany component, the
drainedandflushed.

5.

Reassemblepetcockand

C.FrontAndRearBrake

See

pages158-159foradjustments

1.Brake adjustment
Thebrakescanbeadjustedbysimplyadjusting

the
pistoninthe caliper movesforward
brakepadwearsout,automaticallyadjusting
theclearancebetweenthebrakepadandthe
brake disc.)

all

componentsandreplaceanythat

damaged.Ifthediaphragmisinany way

free

playof

the

brake

is

fuel

install

lever

of

abrasive

tank must be

on

fuel

andpedal.

petcock

damage

tank.

as

the

a.

Frontbrakeleverfreeplay

CAUTION:

toavoidexcessivebrakedrag.

Proper lever freeplayisessential

1)

Loosenthe adjusting screwlocknut.

2)

Byturning the adjustingscrewinorout,
adjusttheplayofthebrake
tighten the locknut.Measurefreeplay
endoflever.

lever

andthen

FREEPLAY

-

at

2.

Brake pad check

To

checkpadwear,openthewearindicator
cap.Ifany pad isworntotheredline,replace
bothpadsinthecaliper.

I

I

FREE PLAY:10mm(0.437in.)

Freeplay:5~8mm(0.2~0.3in.)

b.

Rear

brakepedal free play

CAUTION:

to

avoid

1)

Loosentheadjusterlocknutatthepushrod.

2)

Byturningthe adjuster inorout,adjust
theplayofthebrakepedalandthen tighten
thelock nut.

Properpedalfree

excessive

brakedrag.

playisessential

1

I

3

Checkthebrakefluid

Insufficientbrakefluidrnayallow
thebrakesystem,possiblycausingthebrake
tobecomeineffective.Checkthebrakefluid

level

and replenish when necessaryandobserve

theseprecautions:

a.

Use

onlythedesignatedqualitybrakefluid;
otherwise, the rubber
causingleakageandpoorbrake performance.

level

seals

air

rnaydeteriorate,

toenter

Recommendedbrakefluids:

DOT

No. 3

with

240° C (464°F)

boilingpoint

b.Refillwiththesametypeandbrandofbrake

fluid;mixingfluidsmay result inaharmful

chemical reaction and lead topoor perfor

mance.

-

c.

Be

carefulthatwaterorother contamination

doesnotenterthemastercylinderwhen re

filling.Waterwillsignificantlylower the
boilingpointandmayresultinvaporlock.

2.Frontaxle

-

a.

Checkaxle nuts.

Frontaxlenuttorque:

7.0~10.0m-kg
(50~72ft-lb)

Rearaxlenuttorque:

12~18m-kg

(87~130ft-lb)

b.Checkaxleholdernuts(rightside).

Frontaxleholdernuts:

I

CAUTION: First tighten the nutonthefront
end

of

nutonthe

1.3-2.3m-kg(9-17ft-lbs)

the

axle holder, and thentighten

rear

end.

1

the

D.

WheelsAndTires

1.

Checkingthealuminumwheels.

a.Checkforcracks,bendsorwarpageofthe

wheels.Ifawheelisdeformedorcracked,
mustbereplaced.

NOTE:ThesealuminumwheelsareNOTde

signedforusewithtubelesstires.

b.

Raise

thewheelofftheground. Spin.

Rimrunoutlimits:

Vertical

Lateral

-

2mm

-1

mm(

(0.08

0.04

in.)

in.)

Rearaxlepinchbolt:

0.45-0.75

m-kg(3-5ft-lbs)

I

3.Tires

it

Tirepressure

1.8

Front

-

,,I

Rear 2.0 kg/cm² | Normal riding

kg/cm²

(26

psi)

(28 psi)

I

b.Checkthetirewear

If

a

tire

treadshowscrosswiselines,itmeans
thatthe
tire.

tireiswornto

its

limit.Replacethe

9. Inspect the O

O-ringifdamaged.

10.

Reinstalltopspring,O-ring,spring

stopperringandrubbercap.

-

ring on the spring

seat.

Replace

seat,

E.FrontForkOil Change

1.

Raise

themachineorremovethefrontwheel

so

thatthereisnoweightonthefrontendof

themachine.

2.

Removethe rubber capfromthetopofeach

fork.

3.

The spring

stopperring(springwire circlip). Itisnecessary
todepressthespring
removethe stopper ring. Removethestopper
ringby carefully pryingoutoneendwith

smallscrewdriver.

4.

Placeopencontainer under eachdrainhole.

Removedrainscrewfromeachouter tube.

seat

and springs

are

retainedbya

seat

andforksprings to

CAUTION:

(wirecirclip).

F.

SteeringHeadAdjustment

a

The

XS750D

bearings.
periodicallyforlooseness.

Procedure

The

STOPPER

steeringheadisfitted with taperedroller

steeringassemblyshould be checked

RING

Alwaysuseanewstopperring

CAUTION:Donotallowoiltocontactdisc
brakecomponents.

5.

Whenmostofthe
raise

andlower the outertubestopump
theremainingoil.Itmaybenecessaryto
removethe spring
themfromfallingoutwhen raising forktubes.

6.

Inspectdrainscrewgasket.Replaceifdamaged.
Reinstalldrainscrew.

7.

Pourspecifiedamountofoilintothefork

innertube.

Frontforkoil(eachfork):170cc

2OW

YamahaForkOil

8.

Afterfilling, slowly pump the outertubesup
anddowntodistribute the oil.

oil

hasdrained,slowly

seat

andtopspringtokeep

1.

Raise

frontendofmachinesothatthereisno

weightonthefrontwheel.

2.

Graspbottomofforksandgentlyrockfork
assemblybackward and forward,checkingfor

loosenessinthesteeringassembly bearings.

3.

adjustable contact

Repeat

NOTE: Point gap must beset before setting timing.

If

thereisloosenessinthesteeringhead,loosen

the crown pinchboltandsteeringfittingbolt.

4.Use steering nut wrench to loosen top steering

fittingnut.Thetop nut

5.

Tightenthelowersteeringfittingnutuntilthe
steeringheadistight,butdoesnotbindwhen

forksareturned.

6.

Retightenthetopsteeringfittingnut,steering

fittingboltandcrownpinchbolt,inthatorder.

7.

Rechecksteeringadjustmenttomakesure
thereisno binding whenthe forks aremoved
fromlocktolock.Ifnecessary,repeatadjust
mentprocedure.

G.ThrottleCableAndGrip Lubrication

serves

asalock nut.

ContactBreaker Gap:

0.3

-

0.4mm (.012~.016 in.)

-

Thethrottletwistgripassemblyshouldbegreased
thetimethatthecableislubricatedsincethegrip

mustberemovedto

cable.Twoscrewsclampthethrottlehousingtothe

handlebar.Oncethesetwo

thecablecanbeheidhightopourinseveraldropsof

lubricant.With the throttlegripdisassembled,coat
theinsidesurfaceof the throttlegripguidetubewith
a

suitable all-purposegreasetocutdownfriction.

H.

LubricationOfLevers,Pedals,Etc.

1.

Lubricatethepivotingpartsofthebrake and

clutchleverswithmotor oil (10W30).

2.Lubricatethe shaft of the brakepedalwith
lithiumsoap

2-5

ELECTRICAL

A.ContactBreakerPoint Adjustment

1.Removebreakerpointcover.

2.

Eachcylinderhas

No. 1(left)cylinder

onthebacking plate. The
cylinder

No.3cylinder
plugwires

3.

Checkcontactbreakerpointgap
gap)withfeelergauge.

get

at

theendofthethrottle

are

removed,theendof

grease.

a set

ofbreakerpoints. The

set

is

markedwith

No.

2 (center)

setismarkedwitha"2",andthe

set

is

marked"3".Thespark

are

alsonumbered.

(at

at

a

"1"

largest

Ifnecessary,adjustbylooseningsecuring
screwsandmovingthe
point.

4.Tightenadjustingscrewsandrecheckbreaker
pointgap.

B.

ContactBreakerPointMaintenance

1.Applyafew drops oflightweightlubricantto
thepointcamlubricators.

2.

Thepointscanbelightlysandedwithfine

emerypapertoremovecorrosion. Then place
a

pieceofcleanpaperbetweenthepointsand

let

themclose. Remove thepaper.

untilnoresidueshows.Thepapermaybe
dippedinlacquerthinner or contactpoint
cleaningfluidtoremoveoilorsandingresidue

fromthepointsurface.

3.

Pointreplacement should benecessaryonly
whenpointgapexceedsmaximumtolerance,
whenthe points becomeseverelypitted,orif
the points becomeshortedorshowfaulty
operation.Newpointsmustbecleanedand
adjusted when installed.

C. IgnitionTiming

1.

Ignition timing ischeckedwithatiminglight

byobservingthe position ofthestationary
pointerandthemarksstampedonthegov
ernorassembly.Thegovernorassembly

markedasfollows:

-

is

8.

upper and

Theaboveprocedureisrecommendedfor
ting ignition timing.However,thefollowing

informationisprovidedsothat the positionof

the

staticpointercanbeverifiedusingadegree

wheel.

set

-

There

lines.TheyindicatetheFullAdvancefiring

rangeforeachcylinder.
ConnecttiminglighttoNo.

2.

IgnitiontimingofNo.1cylindermustbe

first.Connecttiminglightto No.1sparkplug

leadwire.

3.

Startengine

4.

Thestationarypointershouldlineup with the

"1F"

notalign,loosen
screwsandmovethecompletebacking plate
until"1F"andthepointermarksalign.

are

alsothree

timingmarkonthegovernor.Ifitdoes

(3)

pairofunmarked

1

(left)

cylinder.

3

breakerbackingplate

set

Retardedignition:

FullyAdvancedIgnition:

D.

Battery

Apoorlymaintainedbatterywilldeterioratequickly.
Thebatteryfluidshouldbechecked

month.

1.

The

level
lowerlevelmarks.
refilling.Normaltap water containsminerals
which
fillonlywithdistilledwater.

2.Alwaysmakesuretheconnectionsarecorrect
wheninstalling

the

(-)

properlyconnected,properlyrouted,and
notdamagedorobstructed.

are

(+)

terminalandtheblackleadisforthe

terminal.Makesurethebreatherpipe

10°

BTDC

38.5±1.5°

shouldbebetweenthe

Use

only distilled waterfor

harmfultoabattery;therefore,

the

battery. The red lead isfor

at

BTDC

least

once

re

a

-

is
is

5.

Retightenscrew.Checktimingagainforthe

No.

1

cylinder.

6.

Rev

theenginetoabove
shouldindicatetheareaofthe
vance"marksonthegovernor.

NOTE:Retardedignition:

Advancebegins:

FullAdvanceachieved:2,900

7.Repeatprocedure(steps2-7)forremaining
cylinders.Looseneachindividualpoint
semblyplate before adjusting. Retighten
screwsandrechecktiming for eachcylinder.

CAUTION:Neverbend adjusting pointer.

3,000

rpm.Thepointer

1,600'

two

"

fullad

1,100~1,550

as

NOTE: The batterymustbechargedbefore
usingtoinsuremaximumperformance.Failure
toproperlychargethe battery beforefirstuse,
oralow electrolyte
failureofthe battery.

Chargingcurrent:
Charginghours:

E.

Spark

Thesparkplugindicateshow the engineisoperating.

-

If

theengineisoperatingcorrectly.andthemachine

is

beingridden properly, thetipofthe white insulator
aroundthepositiveelectrodeofthesparkplugwillbe
a

mediumtancolor.Iftheinsulator is very darkbrown
orblackcolor, then aplugwithahotterheatrange
might
during the enginebreak-inperiod.Iftheinsulatortip
showsaverylighttanorwhitecolor or isactually

-

purewhiteandglazed,orifelectrodes show signsof
melting,thenasparkplugwithacolderheatrange

required.Remember,the insulator
thepositiveelectrodeofthesparkplugmustbe
medium tan color.Ifitis
timingandignitionadjustments.

Plug

be

required.This situation isquitecommon

level,

willcausepremature

1.4

Amps

10

hrs.

area

not,checkcarburetion,

is

surrounding

a

Thesparkplug must beremovedandchecked.Check

under headlight

springs.

electrodewear,insulatorcolor, and electrode gap.

Sparkpluggap:

0.6~0.7mm(0.02~0.03in.)

Engineheat and combustionchamberdepositswill

causeany spark plugtoslowlybreakdownand erode.

Iftheelectrodesfinallybecometooworn,oriffor

anyreasonyoubelievethesparkplugisnotfunction

ingcorrectly,replace
wayscleanthegasketsurface,useanewgasket,wipe
offany grime thatmightbepresentonthesurfaceof
thesparkplug,andtorque the sparkplug properly.

TighteningTorque:1.5~2.5m-kg

F.

Headlight

1.Headlightbeamadjustment.

it.

Wheninstallingtheplug,al-

ChampionN-7Y

(10.8~18.1ft-lb)

b.Adjustverticallyasfollows:

1) Loosen adjustingscrew
body.

-

Adjustverticallybymovingtheheadlight
body.Whenproper adjustment isdeter
mined,retightenadjustingscrew.

2.Replacingtheheadlightbulb.

-

Whennecessary,adjusttheheadlightbeamas
follows:

a.

Adjusthorizontallybytighteningorloosening
theadjustscrew.

a.

Unhookspringsandpullthedefectiveunitout

of

theshell.

b.

Slipa

c.Adjustheadlightbeam.

newunit into positionandinstall

Toadjusttothe right: Tightenthescrew
Toadjusttothe

left:

Loosenthescrew

NOTE:

It

is

veryfragile.

Takecarenottodamagetheheadlight.

ENGINE OVERHAUL

the"on"position
ating).Disconnectfuelpipes and vacuumpipes
frompetcock.

unless

theengineisoper

-

3-1

ENGINEREMOVAL

NOTE:

toremove

A.

PreparationForRemoval

1.

2.

It

is

notnecessarytoremovetheengine

the

cylinderhead,cylinder, or pistons.

Alldirt,mud,dust
bethoroughlyremovedfrom

theenginebeforeremoval

Thiswill

materialfromenteringtheengine.
Beforeengineremoval

that
equipment so thatyoucanperformaclean
andefficient

helppreventanyharmfulforeign

you

havethe proper tools and cleaning

job.

and

foreign material should

the

exteriorof

and

disassembly.

and

disassembly,besure

3. Duringdisassemblyoftheengine,cleanand

place

all

parts

in

traysinorderofdisassembly.
Thiswillspeedassemblytimeandhelpinsure
correctreinstallationof

all

engine parts.

Liftseatand remove fuel

2.

Removefueltank.

tank

holdingbolt.

4.

Placemachineoncenterstand.Startengine
andallowittowarm up. Stopengineand
drainengine/transmissionoil.

5.

Removeoil filter elementtodrainoilfilter.

6.

If

middlegearcaseistoberemoved,drain

middlegearoil.

7.

Removeairscoopfromcylinderheadcover.

C.

Muffler,Footrest,BrakePedal

Removerearbrakepedalandpassengerright

footrest.

2.

Remove exhaust pipeholdingscrewsfromcy

linderhead.

-

B.

Fuel

TankRemoval

1.

Turnfuelpetcocksto"on"(thereisno"off

position-fuelwillnotflow from apetcockon

"

3. Removeexhaust pipes

assembly.

and

muffler

as

an

D.

to

left

Remove clutch

-

left.

at

SideCover,

1.

2.

Air

CleanerCase

Removeleftandrightside covers.

DOHC

Removescrewsholding intake silencers(left

andright).Removeintakesilencers.

4.

Remove

frame.Notegroundwireconnection
frame bracket.

5.

Pull
cablefromholder attached tothe left carbu
retor.Liftcarburetorsbackand

Removethrottlecablefromcarburetors.

bolts

aircleanercasetotherear.

holdingaircleanercase

to

on

the

3.

Loosen clamps
ercaseandintakemanifolds.Loosenbreather
hoseclamp

holding

at

air

carburetorstoairclean

cleanercasejunction.

6. Removeaircleanercase,

E.

WiringandCables

-

1. Pull

backrubbercoveronclutchadjustor

engine.Disconnectclutchcable.

2.

shaft coupling.

Removesparkplugwiresandtachometercable.

3.

Removetwo
cover.Removestartermotorcover.Disconnect
electricstartercable.

(2)

screwsholdingstartermotor

F.DriveShaftJoint

1.

Pull

rubberboot from driveshaftcouplingto

exposefour

(4)

bolts.

4.

Disconnectgroundwirefrom
case.

5.

Disconnectwiringharnesscouplersonleftside

ofmachine.Removeignition wiring (orange,

yellow, grey, bluewires),generatorwiring

(whitewires),andfieldwiring(green,black

wires).Positionwires

ly

removed.

so that

top

ofengine

theycanbesafe

G.Removal

-

Removefour

2.

Removethree

1.

frame.Removefootrestswiththetwo
enginemountingbolts.

(4)

bolts

ondrive

(3)

enginemountingboltsfrom

(2)

rear

2.

Slideengineforward.Remove engine tothe

right.Positionaboxor other support tothe
rightofthemachineforassistancewhenre
movingtheengine.

3-2

ENGINE

A.

CylinderHeadandCylinderRemoval

NOTE:

movedwithoutremovingengine.

1.

DISASSEMBLY

Cylinderheadandcylindercanbere

Removecylinderheadcover.

-

-