check oil YAMAHA YZ85 2003 User Guide

3 - 23
INSP
ADJ
DRIVE CHAIN SLACK ADJUSTMENT
5. Install:

Drive chain 1

Joint 2

Master link clip 3
CAUTION:
Be sure to install the master link clip to the
direction as shown.
aTurning direction5PA30530
6. Lubricate:

Drive chain
Drive chain lubricant:
SAE 10W-30 motor oil or suit-
able chain lubricants
5PA30540
EC36A060
DRIVE CHAIN SLACK ADJUSTMENT
1. Elevate the rear wheel by placing the suit-
able stand under the engine.
2. Check:

Drive chain slack
a
In the center between the drive axle and
rear wheel axle.
Out of specification → Adjust.
NOTE:
Before checking and/or adjusting, rotate the
rear wheel through several revolutions and
check the slack several times to find the tight-
est point. Check and/or adjust chain slack with
rear wheel in this “tight chain” position.
Drive chain slack:
35 ~ 45 mm (1.4 ~ 1.8 in)
5PA30550

4 - 23
ENG
NOTE:
When you purchase a cylinder, you cannot
designate its size. Choose the piston that
matches the above chart.
ASSEMBLY AND INSTALLATION
Piston ring and piston
1. Install:

Piston ring 1
NOTE:

Take care not to scratch the piston or dam-
age the piston ring.

Align the piston ring gap with the pin 2.

After installing the piston ring, check the
smooth movement of it.
5PA40620
2. Install:

Gasket (cylinder) 1

Small end bearing 2

Dowel pin 3
NOTE:

Apply the engine oil on the bearing (crank-
shaft and connecting rod) and connecting
rod big end washers.

Install the gasket with the seal print side
toward the crankcase.
5PA40630
CYLINDER HEAD, CYLINDER AND PISTON

4 - 24
ENG
3. Install:

Piston 1

Piston pin 2

Piston pin clip 3
NOTE:

The arrow a on the piston dome must point
to exhaust side.

Before installing the piston pin clip, cover the
crankcase with a clean rag to prevent the
piston pin clip from falling into the crankcase
cavity.
CAUTION:
Do not allow the clip open ends to meet the
piston pin slot b.
5PA40640
5PA40650
Cylinder head and cylinder
1. Apply:

Engine oil
To piston 1, piston ring 2 and cylinder
surface.
2. Install:

Cylinder 1
CAUTION:
Make sure the piston ring is properly posi-
tioned. Install the cylinder with one hand
while compressing the piston ring with the
other hand.
NOTE:
After installing, check the smooth movement of
the piston.
5PA40660
5PA40670
3. Install:

Nut (cylinder) 1
NOTE:
Tighten the nuts in stage, using a crisscross
pattern.
5PA40680
T R..28 Nm (2.8 m · kg, 20 ft · lb)
CYLINDER HEAD, CYLINDER AND PISTON

4 - 37
ENG
2. Install:

Stopper lever assembly 1
To shift shaft 2.
NOTE:
Apply the transmission oil on the stopper lever
assembly.
5PA41070
Shift shaft
1. Install:

Shift shaft 1
NOTE:

Apply transmission oil on the shift shaft.

When installing the shift shaft, align the stop-
per lever roller with the slot on segment.

When installing the shift shaft, make sure
that the torsion spring 2 is in the position as
shown.
5PA41080
5PA41090
2. Check:

Shift lever 1 position
Gaps a and b are not equal except in
neutral → Replace the shift shaft.
5PA41100
Kick shaft assembly
1. Install:

Kick gear 1

Washer 2

Torsion spring 3
To kick shaft 4.
NOTE:
Make sure the stopper a of the torsion spring
fits into the hole c in the other side of the
stopper b of the kick shaft.
5PA41110
KICK SHAFT, SHIFT SHAFT AND PRIMARY DRIVE GEAR

4 - 57
ENG
Crankshaft
1. Install:

Crankshaft 1
Use the crankshaft installing tool 2, 3, 4.
ÈFor USA and CDN
ÉExcept for USA and CDN
NOTE:

Hold the connecting rod at top dead center
with one hand while turning the nut of the
installing tool with the other. Operate the
installing tool until the crankshaft bottoms
against the bearing.

Before installing the crankshaft, clean the
contacting surface of crankcase.

Apply the lithium soap base grease on the oil
seal lip.
CAUTION:
Do not use a hammer to drive in the crank-
shaft.
Crankshaft installing pot 2:
YU-90050/90890-01274
Crankshaft installing bolt 3:
YU-90050/90890-01275
Adapter (M10) 4:
YM-1277/90890-01277
5PA41720
ÈÉ
5PA41730
2. Check:

Shifter operation

Transmission operation
Unsmooth operation → Repair.
3. Apply:

Sealant
On the right crankcase 1.
NOTE:
Clean the contacting surface of left and right
crankcase before applying the sealant.
Quick gasket®:
ACC-QUICK-GS-KT
YAMAHA Bond No. 1215:
90890-85505
5PA41740
5PA41750
CRANKCASE AND CRANKSHAFT

4 - 58
ENG
4. Install:

Dowel pin 1

Right crankcase 2
To left crankcase 3.
NOTE:

Turn the shift cam 4 to the position shown in
the figure so that it does not contact the
crankcase when installing the crankcase.

Fit the right crankcase onto the left crank-
case. Tap lightly on the case with soft ham-
mer.

When installing the crankcase, the connect-
ing rod should be positioned at TDC (top
dead center).
5PA41760
5PA41770
5. Install:

Clamp 1

Screw (crankcase) 2
NOTE:
Tighten the crankcase tightening screws in
stage, using a crisscross pattern.
5PA41780
T R..8 Nm (0.8 m · kg, 5.8 ft · lb)
6. Install:

Crankcase oil seal holder 1

Bolt (crankcase oil seal holder) 2
7. Remove:

Sealant
Forced out on the cylinder mating surface.
8. Apply:

Engine oil
To the crank pin, bearing, oil delivery hole
and connecting rod end washer.
9. Check:

Crankshaft and transmission operation
Unsmooth operation → Repair.
5PAR0010
T R..20 Nm (2.0 m · kg, 14 ft · lb)
CRANKCASE AND CRANKSHAFT

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ENG
Shift fork, shift cam and segment
1. Inspect:

Shift fork 1
Wear/damage/scratches → Replace.

Straight pin 2
Wear/damage → Replace.
5PA41840
2. Inspect:

Shift cam 1

Guide bar 2
Bend/wear/damage → Replace.
5PA41850
3. Check:

Shift fork movement
On its guide bar.
Unsmooth operation → Replace shift fork
and/or guide bar.
NOTE:
For a malfunctioning shift fork, replace not only
the shift fork itself but the two gears each adja-
cent to the shift fork.5PA41860
EC4H5000
ASSEMBLY AND INSTALLATION
Transmission
1. Install:

5th pinion gear (23T) 1

3rd/4th pinion gear (17T/17T) 2

6th pinion gear (25T) 3

2nd pinion gear (17T) 4
To main axle 5.
NOTE:

Apply the molybdenum disulfide oil on the
5th and 6th pinion gears inner circumference
and on the end surface.

Apply the transmission oil on the 3rd/4th and
2nd pinion gears inner circumference.
5PA41870
TRANSMISSION, SHIFT CAM AND SHIFT FORK

4 - 64
ENG
3. Install:

Guide bar (long) 1

Guide bar (short) 2
NOTE:

Apply the transmission oil on the guide bars.

Be sure the long bar is inserted into the shift
forks #1 and #3 and the short one into #2.
5PA41960
4. Check:

Shifter operation

Transmission operation
Unsmooth operation → Repair.
5PA41970
TRANSMISSION, SHIFT CAM AND SHIFT FORK

5 - 35
CHAS
13. Check:

Inner tube smooth movement
Tightness/binding/rough spots → Repeat
the steps 2 to 12.
5PA51080
14. Compress the front fork fully.
15. Fill:

Front fork oil
Until outer tube top surface with recom-
mended fork oil 1.
CAUTION:

Be sure to use recommended fork oil. If
other oils are used, they may have an
excessively adverse effect on the front
fork performance.

Never allow foreign materials to enter the
front fork.
Recommended oil:
Suspension oil “01”
5PA51090
16. After filling, pump the damper rod 1 slowly
up and down more than 10 times to distrib-
ute the fork oil.
17. Fill:

Front fork oil
Until outer tube top surface with recom-
mended fork oil once more.
5PA51100
18. After filling, pump the outer tube 1 slowly
up and down (about 150 mm (5.9 in)
stroke) to distribute the fork oil once more.
NOTE:
Be careful not to excessive full stroke. A stroke
of 150 mm (5.9 in) or more will cause air to
enter. In this case, repeat the steps 15 to 18.
5PA51110
FRONT FORK

5 - 36
CHAS
19. Wait ten minutes until the air bubbles have
been removed from the front fork, and the
oil has dispense evenly in system before
setting recommended oil level.
NOTE:
Fill with the fork oil up to the top end of the
outer tube, or the fork oil will not spread over to
every part of the front forks, thus making it
impossible to obtain the correct level.
Be sure to fill with the fork oil up to the top of
the outer tube and bleed the front forks.
20. Measure:

Oil level (left and right) a
Out of specification → Adjust.
NOTE:
Be sure to install the spring guide 2 when
checking the oil level.
WARNING
Never fail to make the oil level adjustment
between the maximum and minimum level
and always adjust each front fork to the
same setting. Uneven adjustment can
cause poor handling and loss of stability.
Standard oil level:
90 mm (3.54 in)
Extent of adjustment:
80 ~ 120 mm (3.15 ~ 4.72 in)
From top of outer tube with
inner tube and damper rod 1
fully compressed without
spring.
5PA51120
FRONT FORK