brake YAMAHA YZ250LC 2001 Manuale duso (in Italian)

3-23
REAR BRAKE PAD INSULATOR INSPECTION
BRAKE FLUID LEVEL INSPECTIONINSP
ADJ
EC36b000
REAR BRAKE PAD INSULATOR
INSPECTION
1. Remove:
9Brake pad
Refer to
“REAR BRAKE PAD INSPEC-
TION AND REPLACEMENT” section.
2. Inspect:
9Rear brake pad insulator 1
Damage ÕReplace.
EC367001
BRAKE FLUID LEVEL INSPECTION
1. Place the master cylinder so that its top is in
a horizontal position.
2. Inspect:
9Brake fluid level
Fluid at lower level ÕFill up.
aLower level
Front
õRear
w
9Use only designated quality brake fluid to
avoid poor brake performance.
9Refill with same type and brand of brake flu-
id; mixing fluids could result in poor brake
performance.
9Be sure that water or other contaminants do
not enter master cylinder when refilling.
9Clean up spilled fluid immediately to avoid
erosion of painted surfaces or plastic parts.
Recommended brake fluid:
DOT #4
5MW-9-30-3B 7/3/00 3:21 PM Page 14

3-26
FRONT FORK INSPECTION
INSP
ADJ
3. Adjust:
9Drive chain slack
EC36C000
FRONT FORK INSPECTION
1. Inspect:
9Front fork smooth action
Operate the front brake and stroke the
front fork.
Unsmooth action/oil leakage ÕRepair or
replace.
Drive chain slack adjustment steps:
9Loosen the axle nut 1and locknuts 2.
9Adjust chain slack by turning the
adjusters 3.
To tighten ÕTurn adjuster 3 3
counter-
clockwise.
To loosen ÕTurn adjuster 3 3
clockwise
and push wheel forward.
9Turn each adjuster exactly the same amount
to maintain correct axle alignment. (There are
marks aon each side of chain puller align-
ment.)
NOTE:
Turn the adjuster so that the chain is in line
with the sprocket, as viewed from the rear.
cC
Too small chain slack will overload the
engine and other vital parts; keep the
slack within the specified limits.
9Tighten the axle nut while pushing down the
drive chain.
9Tighten the locknuts.
Axle nut:
125 Nm (12.5 m•kg, 90 ft•lb)
5MW-9-30-3B 7/3/00 3:23 PM Page 20

3-37
LUBRICATION
INSP
ADJ
EC36a042
LUBRICATION
To ensure smooth operation of all components,
lubricate your machine during setup, after break-
in, and after every race.
1All control cable
2Clutch lever pivot
3Shift pedal pivot
4Footrest pivot
5Throttle-to-handlebar contact
6Drive chain
7Throttle roller sliding surface
8Tube guide cable winding portion
9Throttle cable end
0Clutch cable endUse Yamaha cable lube or equivalent on
these areas.
õUse SAE10W-30 motor oil or suitable chain
lubricants.
‚Lubricate the following areas with high quali-
ty, lightweight lithium-soap base grease.
cC
Wipe off any excess grease, and avoid getting
grease on the brake discs.
A
A
CC
AB
AA
5MW-9-30-3B 7/3/00 3:30 PM Page 42

4-32
CLUTCH AND PRIMARY DRIVEN GEARENG
Extent of removal Order Part name Q’ty Remarks
CLUTCH PLATE AND
FRICTION PLATE REMOVAL
Preparation for Drain the transmission oil.
Refer to “TRANSMISSION OIL REPLACE-
removalMENT“ section in the CHAPTER 3.
Bolt (brake pedal) Shift the brake pedal downward.
Rotor and stator Refer to
“CDI MAGNETO“section.
Clutch cable Disconnect at engine side.
1 Clutch cover 1
2 Screw (clutch spring) 6
3 Clutch spring 6
4 Pressure plate 1
5 Friction plate 8
6 Clutch plate 7
Extent of removal:1Clutch plate and friction plate removal
EC490000
CLUTCH AND PRIMARY DRIVEN GEAREC498000
CLUTCH PLATE AND FRICTION PLATE
1
10 Nm (1.0 m•kg, 7.2 ft•lb)
10 Nm (1.0 m•kg, 7.2 ft•lb)
5MW-9-30-4B 7/3/00 6:27 PM Page 12

4-39
KICK AXLE, SHIFT SHAFT AND PRIMARY DRIVE GEARENG
Extent of removal Order Part name Q’ty Remarks
RPIMARY DRIVE GEAR REMOVAL
Preparation for Drain the transmission oil.Refer to “TRANSMISSION OIL REPLACE-
removalMENT“ section in the CHAPTER 3.
Bolt (brake pedal) Shift the brake pedal downward.
Radiator hose 4 Disconnect at water pump side.
Bolt (push rod)
Refer to “CYLINDER HEAD, CYLINDER
AND PISTON” section.
1 Kick starter 1
2 Crankcase cover (right) 1
3 Bolt (Primary drive gear) 1 Only loosening
Refer to “REMOVAL POINTS”.
4 Primary driven gear 1 Refer to “CLUTCH AND PRIMARY
DRIVEN GEAR”section.
5 Primary drive gear 1
6 Thrust plate 1
EC4C0000
KICK AXLE, SHIFT SHAFT AND PRIMARY DRIVE GEAREC4C8000
PRIMARY DRIVE GEAR
1
Extent of removal:1Primary drive gear removal
30 Nm (3.0 m•kg, 22 ft•lb)
10 Nm (1.0 m•kg, 7.2 ft•lb)
55 Nm (5.5 m•kg, 40 ft•lb)
5MW-9-30-4B 7/3/00 7:05 PM Page 26

4-60
ENGINE REMOVALENG
Extent of removal:1Engine removal
Extent of removal Order Part name Q’ty Remarks
1 Chain cover 1
2 Nut (drive sprocket) 1
3 Lock washer 1 Refer to “REMOVAL POINTS”.
4 Drive sprocket 1
5 Clip 1
6 Bolt (brake pedal) 1
7 Brake pedal 1
8 Engine bracket 2
9 Engine mounting bolt 3
10 Pivot shaft 1
Refer to “REMOVAL POINTS”.
11 Engine 1
1
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26 Nm (2.6 m•kg, 19 ft•lb)
69 Nm (6.9 m•kg, 50 ft•lb)
34 Nm (3.4 m•kg, 24 ft•lb)
69 Nm (6.9 m•kg, 50 ft•lb)
75 Nm (7.5 m•kg, 54 ft•lb)
8 Nm (0.8 m•kg, 5.8 ft•lb)
85 Nm (8.5 m•kg, 61 ft•lb)
5MW-9-30-4C 7/3/00 7:48 PM Page 24

4-61
ENGINE REMOVALENG
EC4M3301
Engine removal
1. Remove:
9Pivot 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.
2. Remove:
9Engine 1
From right side.
NOTE:
Make sure that the couplers, hoses and cables
are disconnected.
EC4M3000
REMOVAL POINTS
EC4F3100
Drive sprocket
1. Remove:
9Nut (drive sprocket) 1
9Lock washer 2
NOTE:
9Straighten the lock washer tab.
9Loosen the nut while applying the rear brake.
2. Remove:
9Drive sprocket 1
9Drive chain 2
NOTE:
Remove the drive sprocket together with the
drive chain.
5MW-9-30-4C 7/3/00 7:48 PM Page 26

4-62
ENGINE REMOVALENG
EC4M5341
Drive sprocket
1. Install:
9Drive sprocket 1
9Drive chain 2
NOTE:
Install the drive sprocket together with the drive
chain.
EC4M5211
Brake pedal
1. Install:
9Spring 1
9Brake pedal 2
9O-ring 3
9Bolt (brake pedal) 4
9Clip 5
NOTE:
9Apply the lithium soap base grease on the bolt,
O-rings and brake pedal bracket.
9Install the clip with its stopper portion afacing
inward.
EC4M5000
ASSEMBLY AND INSTALLATIONEC4M5123
Engine installation
1. Install:
9Engine 1
Install the engine from right side.
9Pivot shaft 2
9Engine mounting bolt (lower) 3
9Engine mounting bolt (front) 4
9Engine bracket 5
9Bolt (engine bracket) 6
9Engine mounting bolt (upper) 7
NOTE:
Apply the molybdenum disulfide grease on the
pivot shaft.
85 Nm (8.5 m•kg, 61 ft•lb)
69 Nm (6.9 m•kg, 50 ft•lb)
69 Nm (6.9 m•kg, 50 ft•lb)
34 Nm (3.4 m•kg, 24 ft•lb)
69 Nm (6.9 m•kg, 50 ft•lb)
26 Nm (2.6 m•kg, 19 ft•lb)
5MW-9-30-4C 7/3/00 7:49 PM Page 28

4-63
ENGINE REMOVALENG
3. Bend the lock washer tab to lock the nut.
4. Install:
9Chain guide 1
9Chain cover 2
9Screw (chain cover) 3 2. Install:
9Lock washer 1
9Nut (drive sprocket) 2
NOTE:
Tighten the nut while applying the rear brake.
8 Nm (0.8 m•kg, 5.8 ft•lb)
75 Nm (7.5 m•kg, 54 ft•lb)
5MW-9-30-4C 7/4/00 9:24 AM Page 30

5-1
CHASFRONT WHEEL AND REAR WHEEL
Extent of removal Order Part name Q’ty Remarks
FRONT WHEEL REMOVAL
Preparation for
Hold the machine by placing the
removalsuitable stand under the engine.
1 Hose cover 1
2 Bolt (brake hose holder) 2 Only loosening.
3 Bolt (axle holder) 4 Only loosening.
4 Nut (front wheel axle) 1
5 Front wheel axle 1
6 Front wheel 1
7 Collar 2
8 Oil seal 2
9 Bearing 2 Refer to “REMOVAL POINTS”.
10 Brake disk 1
EC500000
CHASSISEC590000
FRONT WHEEL AND REAR WHEELEC598000
FRONT WHEEL
2
13
3
Extent of removal:1Front wheel removal2Wheel bearing removal3Break disc removal
w
Support the machine securely so there is no dan-
ger of it falling over.
5
23 Nm (2.3 m•kg, 17 ft•lb)
23 Nm (2.3 m•kg, 17 ft•lb)
10 Nm (1.0 m•kg, 7.2 ft•lb)
105 Nm (10.5 m•kg, 75 ft•lb)
16 Nm (1.6 m•kg, 11 ft•lb)
7 Nm (0.7 m•kg, 5.1 ft•lb)
12 Nm (1.2 m•kg, 8.7 ft•lb)
5MW-9-30-5A 7/6/00 8:20 AM Page 2