2004 YAMAHA YZ85 steering

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

1 - 2
GEN
INFO
MACHINE IDENTIFICATION
EC120001
MACHINE IDENTIFICATION
There are two significant reasons for knowing
the serial number of your machine:
1. When ordering parts, you can give the
number to your Yamaha dealer for positive
identification of the model you own.
2. If your machine is stolen, the authorities will
need the number to search for and identify
your machine.
EC121001
VEHICLE IDENTIFICATION NUMBER
The vehicle identification number 1 is
stamped on the right of the steering head pipe.
5PA10040
EC123001
ENGINE SERIAL NUMBER
The engine serial number 1 is stamped into
the elevated part of the right-side of the
engine.
5PA10050
EC124000
MODEL LABEL
The model label 1 is affixed to the frame
under the rider’s seat. This information will be
needed to order spare parts.
5PA10060

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
YM-01495, 90890-01495 Drive gear holder
This tool is used when removing or tightening the pri-
mary drive gear securing nut.YM-01495 90890-01495
Part number Tool name/How to use Illustration
5PA10360

GEN
INFO
1 - 16
TORQUE-CHECK POINTS
TORQUE-CHECK POINTS
Frame construction
Combined seat and fuel tank
Engine mounting
Steering Steering stem to
handlebar
Suspension Front Steering stem to front
fork
Rear For link type
Rear Installation of rear
shock absorber
Rear Installation of swin-
garm
Wheel Installation of wheel Front
Rear
Brake Front
Rear
Fuel systemFrame to rear frame
Fuel tank to frame
Frame to engine
Steering stem to upper bracket
Upper bracket to handlebar
Front fork to upper bracket
Front fork to lower bracket
Assembly of links
Link to frame
Link to rear shock absorber
Link to swingarm
Rear shock absorber to frame
Tightening of pivot shaft
Tightening of wheel axle
Tightening of wheel axle
Wheel to rear wheel sprocket
Brake caliper to front fork
Brake disc to wheel
Tightening of union bolt
Brake master cylinder to handlebar
Tightening of bleed screw
Brake caliper to bracket
Brake disc to wheel
Tightening of union bolt
Brake master cylinder to frame
Tightening of bleed screw
Fuel tank to fuel cock
NOTE:
Concerning the tightening torque, refer to
“MAINTENANCE SPECIFICATIONS” section
in the CHAPTER 2.

SPEC
2 - 8
MAINTENANCE SPECIFICATIONS
CHASSIS
YZ85
Item Standard Limit
Steering system:
Steering bearing type Taper roller bearing ----
Front suspension:
Front fork travel 275 mm (10.8 in) ----
Fork spring free length 430 mm (16.9 in) 425 mm (16.7 in)
Spring rate, STD K = 2.84 N/mm
(0.29 kg/mm, 16.2 lb/in)----
Optional spring Yes ----
Oil capacity318 cm
3
(11.2 Imp oz, 10.8 US oz) ----
Oil level 90 mm (3.54 in) ----

(From top of outer tube with inner
tube and damper rod fully com-
pressed without spring.)80 ~ 120 mm (3.15 ~ 4.72 in) ----
Oil grade Suspension oil “01”----
Inner tube outer diameter 36 mm (1.42 in) ----
Front fork top end 24 mm (0.94 in) ----
Rear suspension: USA, CDN,
AUS, NZ, ZAEUROPE
Shock absorber travel 102 mm (4.02 in)←----
Spring free length 220 mm (8.66 in)←----
Fitting length 215 mm (8.46 in) 212 mm (8.35 in) ----
202.5 ~ 218.5 mm
(7.97 ~ 8.60 in)←----
Spring rate, STD K = 49.0 N/mm
(5.00 kg/mm,
280.0 lb/in)K = 45.0 N/mm
(4.60 kg/mm,
257.6 lb/in)----
Optional spring Yes←----
Enclosed gas pressure 1,000 kPa
(10 kg/cm
2,
142 psi)←----
Swingarm:
Swingarm free play limit
End ---- 1.0 mm (0.04 in)

SPEC
2 - 10
MAINTENANCE SPECIFICATIONS
YZ85LW
Item Standard Limit
Steering system:
Steering bearing type Taper roller bearing ----
Front suspension:
Front fork travel 275 mm (10.8 in) ----
Fork spring free length 430 mm (16.9 in) 425 mm (16.7 in)
Spring rate, STD K = 2.94 N/mm
(0.30 kg/mm, 16.8 lb/in)----
Optional spring Yes ----
Oil capacity318 cm
3
(11.2 Imp oz, 10.8 US oz) ----
Oil level 90 mm (3.54 in) ----

(From top of outer tube with inner
tube and damper rod fully com-
pressed without spring.)80 ~ 120 mm (3.15 ~ 4.72 in) ----
Oil grade Suspension oil “01”----
Inner tube outer diameter 36 mm (1.42 in) ----
Front fork top end Zero mm (Zero in) ----
Rear suspension: AUS, NZ EUROPE
Shock absorber travel 102 mm (4.02 in)←----
Spring free length 220 mm (8.66 in)←----
Fitting length 207 mm (8.15 in) 212 mm (8.35 in) ----
202.5 ~ 218.5 mm
(7.97 ~ 8.60 in)←----
Spring rate, STD K = 51.0 N/mm
(5.20 kg/mm,
291.2 lb/in)K = 47.0 N/mm
(4.80 kg/mm,
268.8 lb/in)----
Optional spring Yes←----
Enclosed gas pressure 1,000 kPa
(10 kg/cm
2,
142 psi)←----
Swingarm:
Swingarm free play limit
End ---- 1.0 mm (0.04 in)

SPEC
2 - 12
MAINTENANCE SPECIFICATIONS
NOTE:
1. First, tighten the steering nut approximately 38 Nm (3.8 m  kg, 27 ft  lb) by using the steering
nut wrench, then loosen the steering nut one turn.
2. Retighten the steering nut 4 Nm (0.4 m  kg, 2.9 ft  lb). Part to be tightened Thread size Q’tyTightening torque
Nm m·kg ft·lb
Upper bracket and outer tube M8 × 1.25 2 22 2.2 16
Lower bracket and outer tube M8 × 1.25 4 20 2.0 14
Upper bracket and steering stem M22 × 1.0 1 125 12.5 90
Handlebar holder and upper bracket M8 × 1.25 4 27 2.7 19
Steering stem and steering ring nut M25 × 1.0 1 Refer to NOTE.
Front fork and front fork cap bolt M40 × 1.0 2 28 2.8 20
Front fork and base valve M22 × 1.0 2 55 5.5 40
Front fork cap bolt and damper rod M10 × 1.0 2 15 1.5 11
Front fork bleed screw and front fork cap bolt M5 × 0.8 2 1 0.1 0.7
Front fork and front fork protector M6 × 1.0 6 7 0.7 5.1
Front fork and brake hose guide M5 × 0.8 1 4 0.4 2.2
Front fork and brake hose holder M6 × 1.0 1 10 1.0 7.2
Throttle grip cap M5 × 0.8 2 4 0.4 2.2
Throttle cable cap M4 × 0.7 2 1 0.1 0.7
Front brake master cylinder M6 × 1.0 2 9 0.9 6.5
Brake lever mounting bolt M6 × 1.0 1 6 0.6 4.3
Brake lever mounting nut M6 × 1.0 1 6 0.6 4.3
Brake lever position locknut M6 × 1.0 1 5 0.5 3.6
Clutch lever holder M5 × 0.8 2 4 0.4 2.2
Front brake master cylinder cap M4 × 0.7 2 2 0.2 1.4
Front brake hose union bolt M10 × 1.25 2 26 2.6 19
Front fork and brake caliper bracket M8 × 1.25 2 30 3.0 22
Brake caliper support bolt M8 × 1.25 1 23 2.3 17
Front brake caliper and bleed screw M7 × 1.0 1 6 0.6 4.3
Rear brake caliper and brake caliper bracket M8 × 1.25 2 23 2.3 17
Rear brake caliper and pad pin M10 × 1.0 2 18 1.8 13
Rear brake caliper and bleed screw M8 × 1.25 1 6 0.6 4.3
Front wheel axle and axle nut M12 × 1.25 1 70 7.0 50
Front brake disc M6 × 1.0 3 12 1.2 8.7
Rear brake disc M6 × 1.0 4 12 1.2 8.7
Rear brake master cylinder M6 × 1.0 2 10 1.0 7.2
Rear brake reservoir tank M6 × 1.0 1 10 1.0 7.2
Rear brake hose union bolt M10 × 1.25 2 26 2.6 19
Rear wheel axle and axle nut M14 × 1.5 1 90 9.0 65

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