relay YAMAHA YZ250LC 2002 Manuale duso (in Italian)

2-10
MAINTENANCE SPECIFICATIONSSPEC
M 6 × 1.0
M10 × 1.25
M10 × 1.25
M20 × 1.5
M 8 × 1.25
–
M 6 × 1.0
M 6 × 1.0
M 8 × 1.25
M10 × 1.25
M10 × 1.25
M10 × 1.25
M16 × 1.5
M14 × 1.5
M14 × 1.5
M14 × 1.5
M10 × 1.25
M10 × 1.25
M 8 × 1.25
M 5 ×0.8
M 4 ×0.7
M 8 × 1.25
M 6 × 1.0
M 5 ×0.8
M 6 × 1.0
M 6 × 1.0
M 6 × 1.0
M 6 × 1.0
M 6 × 1.0
M 8 × 1.25
M 6 × 1.0
M 6 × 1.0
M 6 × 1.0
M 6 × 1.0
M 6 × 1.0 Rear brake reservoir tank and frame
Rear brake hose union bolt (caliper)
Rear brake hose union bolt (master cylinder)
Rear wheel axle and nut
Driven sprocket and wheel hub
Nipple (spoke)
Disc cover and rear brake caliper
Protector and rear brake caliper
Engine mounting:
Engine bracket and frame
Engine and frame (front)
Engine and frame (upper)
Engine and frame (lower)
Pivot shaft and nut
Relay arm and swingarm
Relay arm and connecting rod
Connecting rod and frame
Rear shock absorber and frame
Rear shock absorber and relay arm
Rear frame and frame
Swingarm and brake hose holder
Swingarm and patch
Drive chain tensioner mounting
Chain support and swingarm
Seal guard and swingarm
Fuel tank mounting
Fuel tank and fuel cock
Fuel tank and seat set bracket
Fuel tank and hooking screw (fitting band)
Fuel tank and fuel tank bracket
Seat mounting
Side cover mounting
Air scoop mounting
Front fender mounting
Rear fender mounting
Number platePart to be tightened Thread size Q’tyTightening torque
Nm m•kg ft•lb
1
1
1
1
6
72
2
2
2
1
1
1
1
1
1
1
1
1
3
4
4
2
3
4
2
2
1
1
4
2
2
6
4
4
17
30
30
125
42
3
7
7
34
69
69
69
85
80
80
80
56
53
29
1
2
19
7
6
10
7
7
7
7
19
7
4
7
7
70.7
3.0
3.0
12.5
4.2
0.3
0.7
0.7
3.4
6.9
6.9
6.9
8.5
8.0
8.0
8.0
5.6
5.3
2.9
0.1
0.2
1.9
0.7
0.6
1.0
0.7
0.7
0.7
0.7
1.9
0.7
0.4
0.7
0.7
0.75.1
22
22
90
30
2.2
5.1
5.1
24
50
50
50
61
58
58
58
40
38
21
0.7
1.4
13
5.1
4.3
7.2
5.1
5.1
5.1
5.1
13
5.1
2.9
5.1
5.1
5.1
NOTE:
- marked portion shall be checked for torque tightening after break-in or before each race.
5NX-9-30-2 6/7/01 1:57 PM Page 11

INSP
ADJ
3-2
MAINTENANCE INTERVALS
3
Item Remarks
COOLING SYSTEM
Check coolant level and leakage
Check radiator cap operation
Replace coolantEvery two years
Inspect hoses
OUTSIDE NUTS AND BOLTS Refer to “STARTING
RetightenAND BREAK-IN” section
in the CHAPTER 1.
AIR FILTER
Clean and lubricateUse foam air-filter oil
Replace
FRAME
Clean and inspect
FUEL TANK, COCK
Clean and inspect
BRAKES
Adjust lever position and pedal height
Lubricate pivot point
Check brake disc surface
Check fluid level and leakage
Retighten brake disc bolts, caliper bolts,

master cylinder bolts and union bolts
Replace pads
Replace brake fluidEvery one year
FRONT FORKS
Inspect and adjust
Replace oilSuspension oil “01”
Replace oil seal
FRONT FORK OIL SEAL AND DUST SEAL
Clean and lubeLithium base grease
REAR SHOCK ABSORBER
(After
Inspect and adjustrain ride)
Lube Molybdenum disulfide grease
Retighten
CHAIN GUARD AND ROLLERS
Inspect
SWINGARM
Inspect, lube and retightenMolybdenum disulfide grease
RELAY ARM, CONNECTING ROD
Inspect, lube and retightenMolybdenum disulfide grease
STEERING HEAD
Inspect free play and retighten
Clean and lubeLithium base grease
Replace bearing
TIRE, WHEELS
Inspect air pressure, wheel run-out,

tire wear and spoke looseness
Retighten sprocket bolt
Inspect bearings
Replace bearings
LubricateLithium base grease
THROTTLE, CONTROL CABLE
Check routing and connectionYamaha cable lube or
LubricateSAE 10W-30 motor oil
After
break-
inEvery
raceEvery
thirdEvery
fifthAs re-
quired
5NX-9-30-3A 6/5/01 3:59 PM Page 3

5-52
CHASSWINGARM
Extent of removal Order Part name Q’ty Remarks
SWINGARM REMOVAL
Preparation for
Hold the machine by placing the
removalsuitable stand under the engine.
Brake hose holderRefer to “FRONT BRAKE AND
Rear caliperREAR BRAKE”section.
Bolt (brake pedal) Shift the brake pedal backward.
Drive chain
1 Chain support 1
2 Chain tensioner (lower) 1
3
Bolt (rear shock absorber-relay arm)1 Hold the swingarm.
4 Bolt (connecting rod) 1
5 Pivot shaft 1
6 Swingarm 1
EC570000
SWINGARM
Extent of removal:1Swingarm removal
1
w
Support the machine securely so there is no dan-
ger of it falling over.



53 Nm (5.3 m•kg, 38 ft•lb)
80 Nm (8.0 m•kg, 58 ft•lb)
19 Nm (1.9 m•kg, 13 ft•lb)
7 Nm (0.7 m•kg, 5.1 ft•lb)
85 Nm (8.5 m•kg, 61 ft•lb)
5NX-9-30-5D 6/5/01 4:40 PM Page 2

5-53
CHASSWINGARM
Extent of removal Order Part name Q’ty Remarks
SWINGARM DISASSEMBLY
1Cap 2
2Relay arm 1
3Connecting rod 1
4Collar 2
5Oil seal 2
6Thrust bearing 2
7Bush 2
8Oil seal 8
9Bearing 8 Refer to “REMOVAL POINTS”.
EC578000
SWINGARM DISASSEMBLY
Extent of removal:1Swingarm disassembly 2Connecting rod removal and disassembly
3Relay arm removal and disassembly
1
2
3
23
80 Nm (8.0 m•kg, 58 ft•lb)
6 Nm (0.6 m•kg, 4.3 ft•lb)
2 Nm (0.2 m•kg, 1.4 ft•lb)
80 Nm (8.0 m•kg, 58 ft•lb)
5NX-9-30-5D 6/5/01 4:40 PM Page 4

5-54
CHASSWINGARM
EC573000
REMOVAL POINTS
EC573201
Bearing
1. Remove:
9Bearing 1
NOTE:
Remove the bearing by pressing its outer race.
EC574010
INSPECTION
Wash the bearings, bushes, collars, and covers in
a solvent.
EC574111
Swingarm
1. Inspect:
9Bearing 1
9Bush 2
Free play exists/Unsmooth revolution/Rust 
Replace bearing and bush as a set.
2. Inspect:
9Oil seal 3
Damage Replace.
EC574210
Relay arm
1. Inspect:
9Bearing 1
9Collar 2
Free play exists/Unsmooth revolution/Rust 
Replace bearing and collar as a set.
2. Inspect:
9Oil seal 3
Damage Replace.
EC574310
Connecting rod
1. Inspect:
9Bearing 1
9Collar 2
Free play exists/Unsmooth revolution/Rust 
Replace bearing and collar as a set.
2. Inspect:
9Oil seal 3
Damage Replace.
5NX-9-30-5D 6/5/01 4:40 PM Page 6

5-55
CHASSWINGARM
EC575000
ASSEMBLY AND INSTALLATION
EC575202
Bearing and oil seal
1. Install:
9Bearing 1
9Oil seal 2
To swingarm.
NOTE:
9Apply the molybdenum disulfide grease on the
bearing when installing.
9Install the bearing by pressing it on the side
having the manufacture's marks or numbers.
9First install the outer and then the inner bear-
ings to a specified depth from inside.
2. Install:
9Bearing 1
9Oil seal 2
To relay arm.
NOTE:
9Apply the molybdenum disulfide grease on the
bearing when installing.
9Install the bearing by pressing it on the side
having the manufacture's marks or numbers.
3. Install:
9Bearing 1
9Oil seal 2
To connecting rod.
NOTE:
9Apply the molybdenum disulfide grease on the
bearing when installing.
9Install the bearing by pressing it on the side
having the manufacture's marks or numbers.
Installed depth of bearings:
Outer a a
: Zero mm (Zero in)
Inner b b
: 8.5 mm (0.33 in)
Installed depth of bearings a a
:
5 mm (0.20 in)
Installed depth of bearings a a
:
5 mm (0.20 in)
5NX-9-30-5D 6/5/01 4:40 PM Page 8

5-56
CHASSWINGARM
EC5751B2
Swingarm
1. Install:
9Bush 1
9Thrust bearing 2
9Oil seal 3
9Collar 4
To swingarm 5.
NOTE:
Apply the molybdenum disulfide grease on the
bushes, thrust bearings and oil seal lips.
2. Install:
9Collar 1
To relay arm 2.
NOTE:
Apply the molybdenum disulfide grease on the
collars, bearings and oil seal lips.
3. Install:
9Collar 1
To connecting rod 2.
NOTE:
Apply the molybdenum disulfide grease on the
collar, bearings and oil seal lips.
4. Install:
9Connecting rod 1
9Bolt (connecting rod) 2
9Plain washer 3
9Nut (connecting rod) 4
To relay arm 5.
NOTE:
Apply the molybdenum disulfide grease on the
bolt.
80 Nm (8.0 m•kg, 58 ft•lb)
5NX-9-30-5D 6/5/01 4:40 PM Page 10

5-57
CHASSWINGARM
5. Install:
9Relay arm 1
9Bolt (relay arm) 2
9Plain washer 3
9Nut (relay arm) 4
To swingarm.
NOTE:
9Apply the molybdenum disulfide grease on the
bolt.
9Do not tighten the nut yet.
6. Install:
9Swingarm 1
9Pivot shaft 2
NOTE:
9Apply the molybdenum disulfide grease on the
pivot shaft.
9Insert the pivot shaft from right side.
7. Check:
9Swingarm side play a
Free play exists  Replace thrust bearing.
9Swingarm up and down movement b
Unsmooth movement/Binding/Rough
spotsGrease or replace bearings, bushes
and collars.
8. Install:
9Bolt (connecting rod) 1
9Plain washer 2
9Nut (connecting rod) 3
NOTE:
9Apply the molybdenum disulfide grease on the
bolt.
9Do not tighten the nut yet.
9. Install:
9Bolt (rear shock absorber-relay arm) 1
9Nut (rear shock absorber-relay arm) 2
NOTE:
Apply the molybdenum disulfide grease on the
bolt.
85 Nm (8.5 m•kg, 61 ft•lb)
53 Nm (5.3 m•kg, 38 ft•lb)
5NX-9-30-5D 6/5/01 4:40 PM Page 12

5-58
CHASSWINGARM
10. Tighten:
9Nut (connecting rod) 1
11. Tighten:
9Nut (relay arm) 1
12. Install:
9Cap 1
NOTE:
Install the cap (right) with its mark afacing for-
ward.
13. Install:
9Bolt [chain tensioner (lower)] 1
9Plain washer 2
9Collar 3
9Chain tensioner 4
9Nut [chain tensioner (lower)] 5
14. Install:
9Chain support 1
9Support cover 2
9Bolt {chain support [R=50mm (1.97in)]} 3
9Nut (chain support) 4
9Bolt { support cover [R=10mm (0.39in)]} 5
80 Nm (8.0 m•kg, 58 ft•lb)
7 Nm (0.7 m•kg, 5.1 ft•lb)
7 Nm (0.7 m•kg, 5.1 ft•lb)
19 Nm (1.9 m•kg, 13 ft•lb)
80 Nm (8.0 m•kg, 58 ft•lb)
5NX-9-30-5D 6/5/01 4:40 PM Page 14

5-59
CHASREAR SHOCK ABSORBER
Extent of removal Order Part name Q’ty Remarks
REAR SHOCK ABSORBER
REMOVAL
Preparation forHold the machine by placing the
removalsuitable stand under the engine.
SeatRefer to “SEAT, FUEL TANK AND
SIDE COVERS” section.
SilencerRefer to “EXHAUST PIPE AND
SILENCER” section.
1 Clamp (air cleaner joint) 1 Loosen the screw (air cleaner joint).
2 Rear 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
7 Adjuster 1
8 Spring guide (lower) 1
9 Spring guide (upper) 1
10 Spring (rear shock absorber) 1
11 Bearing 2 Refer to “REMOVAL POINTS”.
2
w
Support the machine securely so there is no dan-
ger of it falling over.
Extent of removal:1Rear shock absorber removal 2Rear shock absorber disassembly
1
56 Nm (5.6 m•kg, 40 ft•lb)
53 Nm (5.3 m•kg, 38 ft•lb)
29 Nm (2.9 m•kg, 21 ft•lb)
EC580000
REAR SHOCK ABSORBER
5NX-9-30-5D 6/5/01 4:41 PM Page 16