Yamaha DT125E 1977 User manual

YAMAHA
DT125E/DT175E
OWNER'SMANUAL
2A6-28199-10

IMPORTANT:PLEASEREADTHISMANUALCAREFULLYANDCOM-
PLETELYBEFOREOPERATINGTHISVEHICLE.
Particularlyimportantinformationisdistinguishedinthismanualbythe fol-
lowingnotations:
NOTE: A NOTEprovideskeyinformationtomakeprocedures
easierorclearer.
CAUTION: A CAUTIONindicatesspecialproceduresthatmustbe fol-
lowedtoavoiddamagetothemachine.
WARNING:A WARNINGindicatesspecialproceduresthatmustbe
followedtoavoidinjurytoa machineoperatororperson
inspectingorrepairingthemachine.
DT125E/DT175EOWNER'SMANUAL
2ND. PRINTING,FEBRUALY1977
ALLRIGHTSRESERVED,
BYYAMAHAMOTORCOMPANY
LIMITED,JAPAN
PRINTEDINJAPAN
P/NLIT-11626-00-70

INTRODUCTION
Congratulationsonyourpurchaseofthe
YamahaDT125E/DT175E.Thismodelrepre-
sentstheproductofmanyyearsofYamaha
experienceintheproductionoffinesporting,
touring, andpace-settingracingmachines.
Youcannowappreciatethehighdegreesof
craftsmanshipandreliabilitythathavemade
Yamahaa leaderinthesefields.
PLEASEREADTHISMANUALCAREFU-
LLYANDCOMPLETELYBEFOREOPERA-
TINGYOURNEWMACHINE.Thismanual
willprovideyouwitha goodbasicunder-
standingofthefeatures,operation,andbasic
maintenanceandinspectionitemsofthis
vehicle.Ifyouhaveanyquestionsregarding
theoperationormaintenanceofyourma-
chine, pleaseconsultyourYamahadealer.
NOTICE:Somedatainthismanualmaybe-
comeoutdatedduetoimprovementsmadeto
thismodelinthefuture.Ifthereisanyques-
tionyouhaveregardingthismanualoryour
machine,pleaseconsultyourYamahadealer.
SERVICEDEPT.
INTERNATIONALDIVISION
YAMAHAMOTORCOMPANY,LTD.

CONTENTS
PAGE
NOMENCLATURE1
MACHINEIDENTIFICATION2
CONTROLFUNCTIONS3
PRE-OPERATIONCHECKS10
OPERATIONANDIMPORTANT
RIDINGPOINTS12
PERIODICMAINTENANCEAND
MINORREPAIR18
CLEANINGANDSTORAGE45
MISCELLANEOUS47
WARRANTYINFORMATION49
SPECIFICATIONS51

NOMENCLATURE
(6)(9
RIGHTSIDE
®(16)
INSTRUMENTS
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
Taillight
Muffler
Kickcrank
Headlight
Frontfender
Frontwheel
Brakepedal
Footrest
Frontfork
Fueltank
11.
12.
13.
14.
15.
Rearwheel
Sidestand
Changepedal
Clutchlever
Speedometer
16. Tachometer
17. Brakelever
18. Throttlegrip
19. Mainswitch
20. Oiltank
-1-

MACHINE
IDENTIFICATION
Frameserialnumber
Theframeserialnumberisstampedonthe
rightsideofthesteeringheadstock.
1. Frameserialnumber
Engineserialnumber
Theengineserialnumberisstampedintothe
raisedpartoftherightrearsectionoftheen-
gine.
NOTE:
Thefirstthreedigitsofthesenumbersarefor
modelidentifications;theremainingdigits
aretheunitproductionnumber.Theengine
andframeserialnumbersareusuallyidentical.

CONTROLFUNCTIONS
Mainswitch
Accordingtothemainkeyposition,the
ignitionandlightingsystemscanbeusedas
follows:
Key
position
OFF
ON
Description
Enginecannotbestarted.
Lightsandhorncannotbe
operated.
Enginecan bestarted.
Lightsandhorncanbe
operated.
.Key
removal
Possible
Notpossible
Hendlebarswitches
Thehandlebarswitchesarelocatednearthe
rightandlefthandlegripsandareusedfor
thefollowingfunctions:
"ENGINESTOP"switch
Makesurethattheenginestopswitchis
turnedto"RUN"position.Theengine
switchhasbeenequippedtoensuresafetyin
anemergencysuchaswhenthemotorcycleis
upsetortroubletakes placeinthethrottle
system. Theenginewillnotstartorrunwhen
theenginestopswitchisturnedto"OFF".
1. "ENGINESTOP"switch

"LIGHTS"switch
Turnthelightswitchtothe"ON"position
toturnontheheadlightandthetaillight.
"LIGHTS"switch(dimmer)
Turntothe"HI"positionforthehighbeam
andtothe"LO"positionforthelowbeam.
1. "LIGHTS"switch3."HORN"switch
2. "LIGHTS"switch(dimmer)4."TURN"switch
"HORN" switch
Pressbuttontosoundthehorn.
"TURN" switch
Thisisa three-wayswitch:thecenterposition
isoff;turntothe"L" positionfortheleft
flasherandtothe"R"positionfortheright
flasher.
Indicatorlights
"TURN" indicatorlight(orange):
Thislightflasheswheneitherturnin-
dicatorisON.
"NEUTRAL"light(green):
Thislightcomesonwhenthetransmission
isinneutral.
"HIGHBEAM"indicatorlight(blue):
Thislightcomesonwhentheheadlight
highbeamisused.
1. "OIL"cautionlight4."TURN"indicatorlight
2. "NEUTRAL"light
3."HIGHBEAM"indicatorlight

"OIL" cautionlight(red):
Thelightcomesonwhenthereislittleoil
intheoiltankthuswarningtherider.The
ridercancheckthecircuitbyputtingthe
machineinneutral.Boththeneutrallight
andtheoilcautionlightshouldcomeon.
NOTE:
Iftheoilcautionlightwillnotlightupduring
thistest,haveyourYamahadealercheckit.
Ofcourse,checktheoillevelfirst.
CAUTION: Donotrunthemachineuntil
youknownthemachinehasenoughoil.
J Mainswitch"ON"
Oilcautionlight
doesnotcomeon
Disconnectedcircuit,
short-ciruit,faulty
cautionlightbulbetc.
Oilcautionlight
comeson
Motorcycleingearl
AskYamahadealerOilcautionlight
toinspectcomeson
Oilcautionlight
doesnotcomeon Supplyengineoil
Speedometer
Theodometerandtripodometerarebuilt
intothespeedometer.Thetripodometercan
beresetto"0"byturningtheresetknob.
1. Resetknob3.,Odometer5.Tachometer
2. Tripodometer4.Speedometerg p;ecj
zone
Tachometer
Thetachometerisprovidedsotheridercan
keepenginerevolutions(rpm)withintheideal
powerrange.
CAUTION: Donotoperateintheredzone.
RedZone:8,000rpmandabove.

Fuelpetcock
Thefuelpetcocksupplysfuelfromthetank
tothecarburetorwhilefilteringthe fuel.
Thefuelpetcockhasthreepositions:
OFF: Withtheleverinthispositionfuelwill
notflow.Alwaysreturntheleverto
thispositionwhentheengineisnot
running.
ON: Withtheleverinthispositionfuel
flowstothecarburetor.Normalriding
isdonewiththeleverinthisposition.
RES: Thisindicates"RESERVE".Ifyourun
outoffuelwhileriding,movethelever
tothisposition.THEN,FILLTHE
TANKATTHEFIRSTOPPORTU-
NITY.
Starterknob
When cold, theenginerequiresa richerfuel
mixtureforstarting.A separatestartercircuit,
whichiscontrolledbythestarterknob,sup-
pliesthismixture.
Pulltheknobouttoopenthecircuitfor
starting. Whentheenginehaswarmeduppush
theknobintoclosethecircuit.
1. Starterknob

Kickstarter
Tostarttheengine,rotatethekickcrank,
pushdownlightlywithyourfootuntilthe
gearsengage,andthenkickwithfullstrength.
Thismodelhasa primarykickstartersothe
enginecanbestartedingeariftheclutchis
disengaged.Asnormalpractices,however,
shifttoneutralbeforestarting.
Steeringlock
Tolockthesteering,turnthehandlebarsto
theright,insertthekeyintothesteering
lockandturnthekeyabout1/8turncounter-
clockwise.Thenpushthekeyinandturnit
about1/8turnclockwise.Checktoseethat
thelockhasengaged,thenremovethekey
fromthelock.Toreleasethelock,reversethe
abovesteps.
Helmetholder
Toopenthehelmetholder,insertthekeyin
thelockandturnitclockwise.
Tolockthehelmetholder,placetheholderin
itsoriginalposition.
-7-

1. Helmetholder2.Open3.Lock
Frontbrakelever
Thefrontbrakeleverislocatedontheright
handlebar.Pullittowardthehandlebarto
activatethefrontbrake.
1. Frontbrakelever
Rearbrakepedal
Therearbrakepedalisontherightsideof
themotorcycle.Pressdownonthebrake
pedaltoactivatetherearbrake.
1. Rearbrakepedal

Clutchlever
Theclutchleverislocatedonthelefthandle-
baranddisengagesorengagestheclutch.
1 • Clutchlever
Pulltheclutchlevertothehandlebartodisen-
gagetheclutchandreleasethelevertoengage
theclutch.Thelevershouldbepulledrapidly
andreleasedslowlyforsmoothoperation.
Gearshifting
Thegearratiosoftheconstantmesh6 speed
transmissionareideallyspaced.Thegearsare
shiftedbyusingthechangepedalontheleft
sideoftheengine.

PRE-OPERATIONCHECKS
Beforeusingthismotorcyclepleasecheckthefollowingpoints:
Item
Brakes
Clutch
Fuel
Autolubetank(Engineoil)
Transmissionoil
Drivechain
Throttle
Wheelsandtires
Lights/signals
Routine
Checkoperation/adjustment
Checkoperation/leveradjustment
Checkfuellevel/top-upasrequired
Checkoillevel/top-upasrequired
Checkoillevel/Fillbeforeeverytrip
Checkalignment/adjustment/lubrication
Checkforproperthrottleandautolubecableoperation
Checkpressure/runout/spoketighteness/axlenuts
Checkheadlight/tail — brakelights/flasherlights/horn
Page
27-30
27
11
21
21-23
30-32
26,27
11,12
-
NOTE: —
Pre-operationchecksshouldbemadeeachtimethemachineisused.Suchaninspectioncanbe
thoroughlyaccomplishedina veryshorttime.Theaddedsafetyitassuresismorethanworth
thetimeinvolved.
-10-

Fuel
Makesurethereissufficientfuelinthetank.
Recommended fuel:
Regularorlowleadgaso
Fueltankcapacity:
7.0lit(1.8US.gal.)
ine
Engineoil
Makesurethereissufficientengineoilinthe
oiltank.Addoilasnecessary.
Recommendedoil:
Seepage21"Engineoilsection"
Oiltankcapacity:
1.0lit(1.1qt.)
Transmissionoil
Makesurethetransmissionoilisatthe
specifiedlevel.Addoilasnecessary.
-1
Recommendedoil:
Yamalube4-cycleor
type"SE"motoroil
Oilquantity:
650+50cc (22.1+ 1.7
3AE10W/30
oz)
Tires
Checkthetirepressureandcheckthetires
forwear.
TirePressure
Off-road
Onpavedroad
Withpassenger
Fronttire
1.0kg/cm2
(14psi)
1.7kg/cm2
(24psi)
1.7kg/cm2
(24psi)
Reartire
1.2kg/cm2
(17psi)
2.0kg/cm2
(28psi)
2.3kg/cm2
(33psi)
Ifa tiretreadshowscross-wiselines,itmeans
thatthetireisworntoitslimit.Replacethe
tire.

Cj
I 1
III
III
p
TIREWEARINDICATOR
WARN I IMG: ft isdangeroustoridewitha
worn-outtire.Whena tiretreadbeginsto
showlines,haveyourYamahadealerreplace
thetireimmediately.
Brakes
Checkforcorrectplayinthebrakeleverand
pedalandmakesuretheyareworkingproper-
ly.Checkthebrakesatlowspeedsshortly
afterstartingout.
Switchesandlights
Checkforproperoperation.
-1
OPERATIONANDIMPORTANT
RIDINGPOINTS
CUATION: Beforeridingthismotorcycle,
becomethoroughlyfamiliarwithalloperat-
ingcontrolsandtheirfunction.
ConsultyourYamahadealerregardingany
controlorfunctionyoudonotthoroughly
understand.
Startinga coldengine
1. Shifttransmissionintoneutral.
2. Turnthefuelpetcockto"ON".
3.Turntheignitionkeyto"ON"position.
NOTE:
Atthistime,bothneutralandoilindicator
lightsshouldbeon.Iflightsdonotcomeon
askYamahadealertoinspect.

4. Turntheenginestopswitchtothe"RUN"
position.
5.Operatethecarburetorstarterjet(choke)
knobandcompletelyclosethethrottle
grip.
6.Kickthekickcrankwithfullstrengthto
starttheengine.
7.Aftertheenginestarts,warmupforone
ortwominutes.Makesurethestarterjet
(choke)knobisreturnedtotheoriginal
positionbeforeriding.
Startinga warmengine
Tostarta warmengine,thestarterknobis
notrequired.
Warmingup
Togetmaximumenginelife,always"warm-
up" theenginebeforeridingthemachine.
Neveracceleratehardwitha coldengine!To
seewhetherornottheengineiswarm,seeif
itrespondstothrottlenormallywiththestar-
terjet(choke)turnedoff.
-1
CAUTION: See"Break-inSection"prior
tooperatingengineforthefirsttime.
Shiftingandacceleration
Thismodelhasa 6-speedtransmission.The
transmissionallowsyoutocontrolthe
amountofpoweryouhaveavailableata given
speedorstartingaccelerating,climbinghills,
etc.ToshiftintoNEUTRAL,repeatedly
depressthechangepedal totheendofits
travel(youwillfeela stopwhenyouarein
firstgear.),thenraiseitslightly.
Tostartoutandaccelerate,proceedas fol-
lows:
1. Pulltheclutchlevertodisengagethe
clutch.
2. ShiftintoFIRSTgear.
3.Openthethrottlegradually,andatthe
sametime,releasetheclutchleverslowly.

1. Changepedal
4. At16to24km/h(10to15mph),closethe
throttle,andatthesametime,pullinthe
clutchleverquickly.
5.ShiftintoSECOND.Becarefulnotto
shiftintoneutral.
6.Openthethrottlepartwayandgradually
releasetheclutchlever.
7.Toaccelerateordecelerate,usethesame
proceduretoshiftintonexthigheror
nextlowergear.
-1
Enginebreak-in
Thereisnevera moreimportantperiod,inthe
lifeofyourmotorcycle,thantheperiodbe-
tweenzeroand800km.(500mi.).Forthis
reasonweaskthatyoucarefullyreadthe fol-
lowingmaterial.Becausetheengineisbrand
new,youmustnotputanexcessiveloadonit
forthefirstseveralhoursofrunning.During
thefirst400km.(250mi.)thevariousparts
intheenginewearandpolishthemselvesto
thecorrectoperatingclearances.Duringthis
periodprolongedfullthrottleoperation,or
anyconditionwhichmightresultinexcessive
heatofcylinder,mustbeavoided.
Ifanyabnormalityisnoticedduringthis
period, askyourYamahadealertocheck.
1. 0~160km.(0~100mi.):
Avoidoperationabove4,000rpm.Allow
acoolingoffperiodof5 to10minutes
aftereveryhourofoperation.Varythe
speedofthemotorcyclefromtimeto
time. Donotoperateitatone,setthrottle
position.

2. 160-400km.(100-250mi.):
Avoidprolongedoperationabove5,000
rpm. Allowthemotorcycletorevfreely
throughthegearsbutdonotusefull
throttleatanytime.
3.400-800km.(250-500mi.):
Avoidprolongedfullthrottleoperation.
Avoidcruisingspeedsinexcessof6,000
rpm.
4. 800km.(500mi.)andbeyond:
Avoidprolongedfullthrottleoperation.
Avoidenginespeedsinexcessof7,000
rpm. Varyspeedsoccasionally.
CAUTION: Ifanyenginetroubleshouldoc-
curduringthebreak-inperiod,consultyour
Yamahadealerimmediately.
Goinguphill
Whenstartingtoclimba gentlegrade,open
thethrottlelittlebylittletoavoidloosing
enginespeedandpower.Whenclimbinga
steepgrade,shiftdownfromTHIRDto
SECONDorfromSECONDtoFIRSTasre-
quired.
Goingdownhill
Ona longdowngradeorsharpdescent,don't
relyonthebrakesalone,butusetheengine
compressionasa brake;shiftintoTHIRDor
SECONDasrequiredbythegradeandclose
thethrottle.

CAUTION: Neverturnofftheignition
switchona long hill. Thismaycausethe
sparkplugto foul, inadditiontobeingun-
safe.
NOTE:
Whenusingenginebrakingforlongperiods,
itisveryimportantnottoexceedmaximum
recommendedrpm(tachometerredzone).It
isalsonecessarytoopenthethrottleocca-
sionallybecausetheenginereliesonthefuel
forinternalcooling.
Stopping
Thereareseveralwaystostop.Pullinginthe
clutchleverandtwistingthethrottlegripin
theclosedirectionwillpermityoutogradual-
lyglidetoa stop.
Downshiftingthroughthegears,usingthe
dragoftheenginetoslowdownisanother.
However,thebestmethod,andtheonemost
universallyused,istousebothenginecom-
pression(downshiftingthroughthegearsas
themachineslows)andthefrontandrear
brakes.
Whenstopping,graduallyapplytherearbrake
whiletwistingthethrottlegripintheclosed
direction. Aftertherearbrakestartstotake
hold, graduallyapplythefrontbrake.Asthe
machinecontinuestoslow,shiftdown
throughthegearsusingenginecompressionto
aidtheslowingeffect.Whenshiftingdown,
watchthetachometertoseethattheengine
doesnotover-rev.
NOTE:
Duringperiodsofinclementweathersuchas
snow, rain, sleet,oriceoronpoorroadsur-
faceswheretractionisminimal,orina sharp
corner,ITISNOTADVISABLETOFIRMLY
APPLYTHEFRONTBRAKE.Whileitistrue
thatthefrontbrakesuppliesthegreaterpor-
tionofbrakingpower,itisalsotruethat