2004 YAMAHA YZ85 brake

4 - 51
ENG
EC4M3000
REMOVAL POINTS
EC4F3100
Drive sprocket
1. Remove:

Nut (drive sprocket) 1

Lock washer 2
NOTE:

Straighten the lock washer tab.

Loosen the nut while applying the rear brake.5PA41510
2. Remove:

Drive sprocket 1

Drive chain 2
NOTE:
Remove the drive sprocket together with the
drive chain.
5PA41520
EC4M3301
Engine removal
1. Remove:

Pivot shaft 1
NOTE:
If the pivot shaft is pulled all the way out, the
swingarm will come loose. If possible, insert a
shaft of similar diameter into the other side of
the swingarm to support it.5PA41530
2. Remove:

Engine 1
From right side.
NOTE:
Make sure that the couplers, hoses and cables
are disconnected.
5PA41540
ENGINE REMOVAL

4 - 52
ENG
EC4M5000
ASSEMBLY AND INSTALLATION
Engine installation
1. Install:

Engine 1
Install the engine from right side.

Pivot shaft 2

Engine mounting bolt (front) 3

Engine mounting bolt (lower) 4
NOTE:
Apply the molybdenum disulfide grease on the
pivot shaft.
5PA41550
T R..63 Nm (6.3 m · kg, 45 ft · lb)
T R..69 Nm (6.9 m · kg, 50 ft · lb)
T R..69 Nm (6.9 m · kg, 50 ft · lb)
Drive sprocket
1. Install:

Drive sprocket 1

Drive chain 2
NOTE:
Install the drive sprocket together with the
drive chain.
5PA41560
2. Install:

Lock washer 1

Nut (drive sprocket) 2
NOTE:
Tighten the nut while applying the rear brake.
3. Bend the lock washer tab to lock the nut.
5PA41570
T R..60 Nm (6.0 m · kg, 43 ft · lb)
4. Install:

Gasket (left crankcase cover)

Left crankcase cover 1

Screw (left crankcase cover) 2
NOTE:
Tighten the screws in stage, using a crisscross
pattern.
5PA41580
T R..5 Nm (0.5 m · kg, 3.6 ft · lb)
ENGINE REMOVAL

5 - 1
CHAS
EC500000
CHASSIS
EC590000
FRONT WHEEL AND REAR WHEEL
EC598000
FRONT WHEEL
FRONT WHEEL AND REAR WHEEL
Extent of removal:
1 Front wheel removal
2 Wheel bearing removal
3 Brake disc removal
Extent of removal Order Part name Q’ty Remarks
Preparation for removalFRONT WHEEL REMOVAL
Hold the machine by placing the
suitable stand under the engine.
WARNING
Support the machine securely so there is nodanger of it falling over.
1 Nut (front wheel axle) 1
2 Front wheel axle 1
3 Front wheel 1
4 Collar 2
5 Oil seal 2
6 Bearing 2 Refer to “REMOVAL POINTS”.
7 Brake disc 1
2
31
3
5PA50010

5 - 2
CHAS
EC598100
REAR WHEEL
5PAR0012
Extent of removal:
1 Rear wheel removal
2 Wheel bearing removal
3 Brake disc removal
Extent of removal Order Part name Q’ty Remarks
Preparation for removalREAR WHEEL REMOVAL
Hold the machine by placing the
suitable stand under the engine.
WARNING
Support the machine securely so there is no
danger of it falling over.
1 Nut (rear wheel axle) 1
2 Rear wheel axle 1
3 Drive chain puller 2
4 Rear wheel 1 Refer to “REMOVAL POINTS”.
5 Collar 2
6 Rear wheel sprocket 1
7 Oil seal 2
8 Circlip 1
9 Bearing 2 Refer to “REMOVAL POINTS”.
10Brake disc
1
2
31
3
FRONT WHEEL AND REAR WHEEL

5 - 4
CHAS
EC514200
Wheel axle
1. Measure:

Wheel axle bends
Out of specification → Replace.
Use the dial gauge 1.
NOTE:
The bending value is shown by one half of the
dial gauge reading.
WARNING
Do not attempt to straighten a bent axle.
Wheel axle bending limit:
0.5 mm (0.020 in)
5PA50070
Brake disc
1. Measure:

Brake disc deflection
Use the dial gauge 1.
Out of specification → Inspect wheel
runout.
If wheel runout is in good condition, replace
the brake disc.
2. Measure:

Brake disc thickness a
Out of limit → Replace.
Brake disc deflection limit:
0.15 mm (0.006 in)
Brake disc thickness:
3.0 mm (0.12 in)
: 2.5 mm (0.10 in)
5PA50080
FRONT WHEEL AND REAR WHEEL

5 - 5
CHAS
EC595000
ASSEMBLY AND INSTALLATION
Front wheel
1. Install:

Bearing (left) 1

Spacer 2

Bearing (right) 3

Oil seal 4
NOTE:

Apply the lithium soap base grease on the
bearing and oil seal lip when installing.

Use a socket that matches the outside diam-
eter of the race of the bearing.

Left side of bearing shall be installed first.

Install the oil seal with its manufacture’s
marks or numbers facing outward.
CAUTION:
Do not strike the inner race of the bearing.
Contact should be made only with the outer
race.
2. Install:

Brake disc 1

Bolt (brake disc) 2
5PA50090
5PA50100
T R..12 Nm (1.2 m · kg, 8.7 ft · lb)
3. Install:

Collar 1
NOTE:
Apply the lithium soap base grease on the oil
seal lip.
5PA50110
4. Install:

Wheel
NOTE:
Install the brake disc 1 between the brake
pads 2 correctly.
5PA50120
FRONT WHEEL AND REAR WHEEL

5 - 7
CHAS
2. Install:

Brake disc 1

Bolt (brake disc) 2
NOTE:
Tighten the bolts (brake disc) in stage, using a
crisscross pattern.
5PA50160
T R..12 Nm (1.2 m · kg, 8.7 ft · lb)
3. Install:

Rear wheel sprocket 1

Bolt (rear wheel sprocket) 2

Washer (rear wheel sprocket) 3

Nut (rear wheel sprocket) 4
NOTE:
Tighten the nuts (rear wheel sprocket) in
stage, using a crisscross pattern.5PA50170
T R..42 Nm (4.2 m · kg, 30 ft · lb)
4. Install:

Collar 1
NOTE:
Apply the lithium soap base grease on the oil
seal lip.
5PA50180
5. Install:

Wheel
NOTE:
Install the brake disc 1 between the brake
pads 2 correctly.
5PA50190
6. Install:

Drive chain 1
NOTE:
Push the wheel 2 forward and install the drive
chain.
5PA50200
FRONT WHEEL AND REAR WHEEL

5 - 9
CHASFRONT BRAKE AND REAR BRAKE
EC5A0000
FRONT BRAKE AND REAR BRAKE
EC5A8000
FRONT BRAKE
5PA50250
Extent of removal:
1 Brake hose removal
2 Brake caliper removal
3 Brake master cylinder removal
Extent of removal Order Part name Q’ty Remarks
Preparation for removalFRONT BRAKE REMOVAL
Hold the machine by placing the
suitable stand under the engine.
WARNING
Support the machine securely so there is no
danger of it falling over.
Drain the brake fluid. Refer to “REMOVAL POINTS”.
1 Protector 1
2 Brake hose holder 1
3 Union bolt 2
4 Brake hose 1
5 Brake caliper support bolt 1
6 Brake caliper 1 Refer to “REMOVAL POINTS”.
7Brake lever 1
8 Brake master cylinder bracket 1
9 Brake master cylinder 1
2
3
132