2003 YAMAHA YZ85 ignition

CHAPTER 5
CHASSIS
FRONT WHEEL AND REAR WHEEL....... 5-1
FRONT BRAKE AND REAR BRAKE....... 5-9
FRONT FORK.......................................... 5-27
HANDLEBAR........................................... 5-41
STEERING............................................... 5-46
SWINGARM............................................. 5-51
REAR SHOCK ABSORBER.................... 5-58
CHAPTER 6
ELECTRICAL
ELECTRICAL COMPONENTS
AND WIRING DIAGRAM........................... 6-1
IGNITION SYSTEM.................................... 6-2
CHAPTER 7
TUNING
ENGINE...................................................... 7-1
CHASSIS................................................. 7-10

GEN
INFO
1 - 8
SPECIAL TOOLS
YU-33975, 90890-01403 Steering nut wrench
This tool is used when tighten the steering ring nut to
specification.YU-33975 90890-01403
YM-01434, 90890-01434 Rod holder
This tool is used to hold the fork spring.YM-01434 90890-01434
YM-01437, 90890-01437
90890-01436Rod puller
Rod puller attachment (M10)
These tools are used to pull up the fork damper rod.YM-01437 90890-01437
90890-01436
YM-01442, 90890-01442 Fork seal driver
This tool is used when install the fork oil seal.YM-01442 90890-01442
YM-01454, 90890-01454 Damper rod holder
Use this tool to remove and install the damper rod.YM-01454 90890-01454
YU-3112-C, 90890-03112 Pocket tester
Use this tool to inspect the coil resistance, output
voltage and amperage.YU-3112-C 90890-03112
YM-91042, 90890-04086 Clutch holding tool
This tool is used to hold the clutch when removing or
installing the clutch boss securing nut.YM-91042 90890-04086
YM-34487
90890-06754Dynamic spark tester
Ignition checker
This instrument is necessary for checking the ignition
system components.YM-34487 90890-06754
ACC-QUICK-GS-KT
90890-85505Quick gasket

YAMAHA Bond No. 1215
This sealant (Bond) is used for crankcase mating sur-
face, etc.ACC-QUICK-GS-KT 90890-85505
Part number Tool name/How to use Illustration
5PA103005PA10300
5PA103105PA10310
5PA10320
5PA103405PA10340
5PA103505PA10350
5PA103605PA10360
5PA103705PA10380
5PA103905PA10400
5PA104105PA10410

SPEC
2 - 3
GENERAL SPECIFICATIONS
Suspension:
Front suspension Telescopic fork
Rear suspension Swingarm (link type monocross suspension)
Shock absorber:
Front shock absorber Coil spring/air, oil damper
Rear shock absorber Coil spring/gas, oil damper
Wheel travel: YZ85 YZ85LW
Front wheel travel 275 mm (10.8 in)←
Rear wheel travel 282 mm (11.1 in) 287 mm (11.3 in)
Electrical:
Ignition system CDI magneto

SPEC
2 - 14
MAINTENANCE SPECIFICATIONS
EC212300
ELECTRICAL
Item Standard Limit
Ignition system:
Ignition timing (B.T.D.C.) 0.9 mm (0.035 in) ----
Advancer type Electrical ----
CDI:
Magneto-model (stator)/manufac-
turer5PA-00/YAMAHA ----
Charging coil 1 resistance (color) 720 ~ 1,080 Ω at 20 °C (68 °F)
(Green/White – Black/Red)----
Charging coil 2 resistance (color) 44 ~ 66 Ω at 20°C (68 °F)
(Black – Green/Blue)----
Pickup coil resistance (color) 248 ~ 372 Ω at 20°C (68 °F)
(White/Blue – White/Red)----
CDI unit-model/manufacturer 5PA-00/YAMAHA ----
Ignition coil:
Model/manufacturer 5PA-00/YAMAHA ----
Minimum spark gap 6 mm (0.24 in) ----
Primary coil resistance 0.18 ~ 0.28 Ω at 20 °C (68 °F) ----
Secondary coil resistance 6.3 ~ 9.5 kΩ at 20 °C (68 °F) ----
Spark plug cap:
Resistance 4 ~ 6 kΩ at 20 °C (68 °F) ----
Part to be tightened Thread size Q’tyTightening torque
Nm m·kg ft·lb
Stator M6 × 1.0 2 8 0.8 5.8
Rotor M10 × 1.25 1 33 3.3 24
Ignition coil M6 × 1.0 2 7 0.7 5.1

2 - 16
SPEC
EC240000
CABLE ROUTING DIAGRAM
1Hose guide
2Brake hose
3Throttle cable
4Fuel tank breather hose
5Engine stop switch lead
6CDI magneto lead
7Clamp
8Carburetor breather hose
9Carburetor overflow hose
0Transmission oil breather hose
ARadiator breather hose
BClutch cable
CSpark plug leadDCable guide
EBrake hose holder
ÈPass the fuel tank breather hose between the
handlebar and tension bar, then insert its end
into the hole of the steering stem.
ÉFasten the ground lead together with the ignition
coil.
ÊClamp the brake hose with the brake hose
holder.
ËFit the brake hose into the guides of the protec-
tor.
CABLE ROUTING DIAGRAM

2 - 17
SPEC
1Sub-wire harness
2CDI unit
3Ignition coil
4Clutch cable
5Cable guide
6Transmission oil breather hose
7CDI unit band
8Clamp
9Brake hose
0Brake hose holder
AHose guide
BReservoir hose
CReservoir tank
DBrake master cylinderÈPass the transmission oil breather hose through
the hose guide.
ÉClamp the sub-wire harness at the tape on it
within the arrow mark.
ÊPass the sub-wire harness on the left of the CDI
unit.
ËPass the reservoir hose between the brake hose
and swingarm bracket.
ÌPass the reservoir hose through the hose guides.
ÍInstall the brake hose so that its pipe portion
directs as shown and lightly touches the projec-
tion on the brake master cylinder.
CABLE ROUTING DIAGRAM

3 - 4
INSP
ADJ
PRE-OPERATION INSPECTION AND MAINTENANCE
EC320000
PRE-OPERATION INSPECTION AND MAINTENANCE
Before riding for break-in operation, practice or a race, make sure the machine is in good operating
condition.
Before using this machine, check the following points.
GENERAL INSPECTION AND MAINTENANCE
Item Routine Page
CoolantCheck that coolant is filled up to the radiator cap.
Check the cooling system for leakage.P.3-5 ~ 9
FuelCheck that a fresh mixture of oil and gasoline is filled in the fuel
tank. Check the fuel line for leakage.P.1-12
Transmission oilCheck that the oil level is correct. Check the crankcase for leak-
age.P.3-12 ~ 13
Gear shifter and clutchCheck that gears can be shifted correctly in order and that the
clutch operates smoothly.P.3-9
Throttle grip/HousingCheck that the throttle grip operation and free play are correctly
adjusted. Lubricate the throttle grip and housing, if necessary.P.3-10
Brakes Check the play of front brake and effect of front and rear brake. P.3-16 ~ 21
Drive chainCheck drive chain slack and alignment. Check that the drive
chain is lubricated properly.P.3-22 ~ 24
WheelsCheck for excessive wear and tire pressure. Check for loose
spokes and have no excessive play.P.3-31 ~ 32
SteeringCheck that the handlebar can be turned smoothly and have no
excessive play.P.3-32 ~ 34
Front forks and rear shock
absorberCheck that they operate smoothly and there is no oil leakage. P.3-24 ~ 30
Cables (wires)Check that the clutch and throttle cables move smoothly. Check
that they are not caught when the handlebars are turned or
when the front forks travel up and down.—
Exhaust pipe and silencerCheck that the exhaust pipe is tightly mounted and has no
cracks.P.4-2
Rear wheel sprocket Check that the rear wheel sprocket tightening bolt is not loose. P.3-22
Lubrication Check for smooth operation. Lubricate if necessary. P.3-35
Bolts and nuts Check the chassis and engine for loose bolts and nuts. P.1-16
Lead connectorsCheck that the CDI magneto, CDI unit, and ignition coil are con-
nected tightly.P.1-6
SettingsIs the machine set suitably for the condition of the racing course
and weather or by taking into account the results of test runs
before racing? Are inspection and maintenance completely
done?P.7-1 ~ 19

3 - 37
INSP
ADJ
IGNITION TIMING CHECK
IGNITION TIMING CHECK
1. Remove:

Air scoop

Spark plug

Left crankcase cover
2. Attach:

Dial gauge 1

Dial gauge stand 2
Dial gauge and stand:
YU-3097/90890-01252
Stand:
YU-12565PA30870
3. Rotate the rotor 1 until the piston reaches
top dead center (TDC). When this hap-
pens, the needle on the dial gauge will stop
and reverse directions even though the
rotor is being turned in the same direction.
4. Set the dial gauge to zero at TDC.
5PA30880
5. From TDC, rotate the rotor clockwise until
the dial gauge indicates that the piston is at
a specified distance from TDC.
Ignition timing (B.T.D.C.):
0.9 mm (0.035 in)
6. Check:

Ignition timing
Punch mark a on rotor should be aligned
with punch mark b on stator.
Not aligned → Adjust.
5PA30890