engine YAMAHA YZ85 2003 Repair Manual

5 - 10
CHAS
EC5A8100
REAR BRAKE
5PAR0016
Extent of removal:
1 Brake caliper removal
2 Brake hose removal
3 Brake master cylinder removal
Extent of removal Order Part name Q’ty Remarks
Preparation for removalREAR 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 Pad pin 2 Loosen when disassembling the caliper.
3 Brake caliper 1
4 Brake hose holder 2
5 Union bolt 2
6 Brake hose 1
7 Brake pedal 1
8 Reservoir tank 1
9 Reservoir hose 1
10 Brake master cylinder 1
3
1
321
FRONT BRAKE AND REAR BRAKE

5 - 27
CHASFRONT FORK
EC550000
FRONT FORK
5PA50820
Extent of removal:
1 Front fork removal
Extent of removal Order Part name Q’ty Remarks
Preparation for removalFRONT FORK 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.
Front wheel Refer to “FRONT WHEEL AND REAR
WHEEL” section.
Front brake caliper Refer to “FRONT BRAKE AND REAR
BRAKE” section.
Number plate
Handlebar Refer to “HANDLEBAR” section.
1 Protector 1
2 Brake hose holder 1
3 Pinch bolt (upper bracket) 1 Only loosening.
4 Cap bolt 1 Loosen when disassembling the front fork.
5 Pinch bolt (lower bracket) 2 Only loosening.
6 Front fork 1
1

5 - 41
CHAS
EC5B0000
HANDLEBAR
5PA51290
Extent of removal:
1 Handlebar removal
Extent of removal Order Part name Q’ty Remarks
Preparation for removalHANDLEBAR REMOVAL
Number plate Remove the clamp portion only.
1 Clutch cable 1 Disconnect at the lever side.
2 Clutch lever holder 1
3 Engine stop switch 1
4 Brake master cylinder 1 Refer to “REMOVAL POINTS”.
5 Throttle cable cap 1
6 Grip cap (lower) 1
7 Grip cap (upper) 1
8 Throttle cable 1 Disconnect at the throttle side.
9 Right grip 1 Refer to “REMOVAL POINTS”.
10 Tube guide 1
11 Collar 1
12 Left grip 1 Refer to “REMOVAL POINTS”.
13 Handlebar upper holder 2
14 Handlebar 1
1
HANDLEBAR

5 - 45
CHAS
7. Install:

Engine stop switch 1

Clutch lever holder 2

Bolts (clutch lever holder) 3

Clamp 4
NOTE:
The engine stop switch and clutch lever holder
should be installed according to the dimen-
sions shown.
5PA51420
T R..4 Nm (0.4 m · kg, 2.9 ft · lb)
5PA51430
8. Install:

Clutch cable 1
NOTE:
Apply the lithium soap base grease on the
clutch cable end.
5PA51440
9. Adjust:

Clutch lever free play
Refer to “CLUTCH ADJUSTMENT” section
in the CHAPTER 3.
10. Clamp the clamp portion a of the number
plate to the handlebar.
11. Insert the end of the fuel tank breather
hose 1 into the hole of the steering stem.
5PA51450
HANDLEBAR

5 - 46
CHAS
EC560000
STEERING
5PAR0017
Extent of removal:
1 Lower bracket removal
2 Bearing removal
Extent of removal Order Part name Q’ty Remarks
STEERING REMOVAL
WARNING
Support the machine securely so there is nodanger of it falling over.
Refer to “HANDLEBAR” section. Preparation for removal Hold the machine by placing the
suitable stand under the engine.
Number plate
Handlebar
Cable guide
Front fender
1 Steering stem nut 1
2 Front fork 2 Refer to “FRONT FORK” section.
3 Upper bracket 1
4 Steering ring nut 1 Use special tool.
Refer to “REMOVAL POINTS”.
5 Lower bracket 1
6 Ball race cover 1
7 Upper bearing 1
8 Lower bearing 1 Refer to “REMOVAL POINTS”.
9Ball race 2Refer to “REMOVAL POINTS”.
2
1
STEERING

5 - 51
CHASSWINGARM
EC570000
SWINGARM
5PAR0019
Extent of removal:
1 Swingarm removal
Extent of removal Order Part name Q’ty Remarks
SWINGARM REMOVAL
WARNING
Support the machine securely so there is no
danger of it falling over.
Preparation for removal Hold the machine by placing the
suitable stand under the engine.
Real wheel Refer to “FRONT WHEEL AND REAR
WHEEL” section.
Brake hose holder
Rear brake caliper
Drive chainRefer to “FRONT BRAKE AND REAR
BRAKE” section.
1 Drive chain support 1
2 Bolt (connecting rod) 1 Hold the swingarm.
3 Bolt (rear shock absorber-relay
arm)1
4 Pivot shaft 1
5 Swingarm 1
1

5 - 58
CHASREAR SHOCK ABSORBER
EC580000
REAR SHOCK ABSORBER
5PA51870
Extent of removal:
1 Rear shock absorber removal
2 Rear shock absorber disassembly
Extent of removal Order Part name Q’ty Remarks
Preparation for removalREAR SHOCK ABSORBER
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.
Seat Refer to “SEAT, FUEL TANK AND SIDE
COVERS” section in the CHAPTER 4.
Silencer Refer to “EXHAUST PIPE AND
SILENCER” section in the CHAPTER 4.
1 Clamp (air cleaner joint) 1 Only loosening.
2Rear frame 1
3 Bolt (rear shock absorber-relay
arm)1 Hold the swingarm.
4 Bolt (rear shock absorber-frame) 1
5 Rear shock absorber 1
6 Locknut 1 Only loosening.
7 Adjuster 1 Only loosening.
8 Spring guide 1
9 Spring (rear shock absorber) 1
1
2

6 - 1
–+ELECELECTRICAL COMPONENTS AND WIRING DIAGRAM
EC600000
ELECTRICAL
EC610000
ELECTRICAL COMPONENTS AND WIRING DIAGRAM
EC611000
ELECTRICAL COMPONENTS
1Engine stop switch
2Ignition coil
3CDI unit
4CDI magneto
5Spark plugCOLOR CODE
B ...................... Black
O ..................... Orange
B/R .................. Black/Red
B/W ................. Black/WhiteG/L................... Green/Blue
G/W ................. Green/White
W/L .................. White/Blue
W/R ................. White/Red
EC612000
WIRING DIAGRAM
5PA60010
5PA60020

6 - 2
–+ELECIGNITION SYSTEM
EC620000
IGNITION SYSTEM
INSPECTION STEPS
Use the following steps for checking the possibility of the malfunctioning engine being attributable to
ignition system failure and for checking the spark plug which will not spark.
*marked: Only when the ignition checker is used.
NOTE:

Remove the following parts before inspection.
1) Seat
2) Fuel tank

Use the following special tools in this inspection.
Dynamic spark tester:
YM-34487
Ignition checker:
90890-06754Pocket tester:
YU-3112-C/90890-03112
Spark gap test*Clean or replace
spark plug.
Check entire ignition
system for connection.Repair or replace.
Check engine stop switch. Replace.
Check ignition coil. Primary coil Replace.
Secondary coil Replace.
Check spark plug cap. Replace.
Check CDI magneto. Pickup coil Replace.
Charging coil Replace.
Replace CDI unit.
No spark
OK
OK
OK
OK
OK
Spark
No good
No good
No good
No good
No good
No good
No good

6 - 3
–+ELECIGNITION SYSTEM
SPARK GAP TEST
1. Disconnect the spark plug cap from spark
plug.
2. Connect the dynamic spark tester 1 (igni-
tion checker 2) as shown.

Spark plug cap 3

Spark plug 4
ÈFor USA and CDN
ÉExcept for USA and CDN
3. Kick the kickstarter crank.
4. Check the ignition spark gap.
5. Start engine, and increase spark gap until
misfire occurs. (for USA and CDN only)
Minimum spark gap:
6.0 mm (0.24 in)
È
5PA60030
É
5PA60040
EC624000
COUPLERS AND LEADS CONNECTION
INSPECTION
1. Check:

Couplers and leads connection
Rust/dust/looseness/short-circuit → Repair
or replace.
ENGINE STOP SWITCH INSPECTION
1. Inspect:

Engine stop switch conduct
No continuous while being pushed → Replace.
Continuous while being freed → Replace. Tester (+) lead
→ Black/White lead
1
Tester (–) lead
→ Black lead
2
B/W
1B
2Tester selec-
tor position
PUSH IN
Ω
× 1
FREE
5PA60050