2006 YAMAHA YZ250LC wheel

2-8
MAINTENANCE SPECIFICATIONSSPEC
Item Standard Limit
Wheel:
Front wheel type Spoke wheel…
Rear wheel type Spoke wheel…
Front rim size/Material 21 ×1.60/Aluminum…
Rear rim size/Material 19 ×2.15/Aluminum…
Rim runout limit:
Radial…
2.0 mm (0.08 in)
Lateral…
2.0 mm (0.08 in)
Drive chain
Type/Manufacturer DID520DMA2 SDH/DAIDO…
Number of links 113 links + joint…
Chain slack 48~58 mm (1.9~2.3 in)…
Chain length (15 links)…
242.9 mm (9.563 in)
Front disc brake:
Disc outside dia. ×Thickness 250 ×3.0 mm 250 ×2.5 mm
(9.84 ×0.12 in) (9.84 ×0.10 in)
Pad thickness 4.4 mm (0.17 in) 1.0 mm (0.04 in)
Master cylinder inside dia. 11.0 mm (0.433 in)…
Caliper cylinder inside dia. 27.0 mm (1.063 in) ×2…
Brake fluid type DOT #4…
Rear disc brake:
Disc outside dia. ×Thickness 245 ×4.0 mm 245 ×3.5 mm
(9.65 ×0.16 in) (9.65 ×0.14 in)
Deflection limit…
0.15 mm (0.006 in)
Pad thickness 6.4 mm (0.25 in) 1.0 mm (0.04 in)
Master cylinder inside dia. 11.0 mm (0.433 in)…
Caliper cylinder insdie dia. 25.4 mm (1.000 in)…
Brake fluid type DOT #4…
Brake lever & brake pedal:
Brake lever position 95 mm (3.74 in)…
Brake pedal height Zero mm (Zero in)…
(vertical height above footrest top)
Clutch lever free play (lever end) 8~13 mm (0.31~0.51 in)…
Throttle grip free play 3~5 mm (0.12~0.20 in)…
1P8-9-31-2 5/19/05 10:30 AM Page 9

2-9
MAINTENANCE SPECIFICATIONSSPEC
17
14
105
20
29
22
40
21
21
0.7
5.1
5.1
0.7
2.9
2.9
2.9
6.5
1.4
4.3
4.3
3.6
2.9
22
22
17
7.2
2.2
13
4.3
75
17
8.7
10
40
19
7.2M 8 × 1.25
M 8 × 1.25
M24 × 1.0
M 8 × 1.25
M12 × 1.25
M28 × 1.0
M51 × 1.5
M22 × 1.25
M42 × 1.5
M12 × 1.25
M 5 × 0.8
M 6 × 1.0
M 6 × 1.0
M 4 × 0.7
M 6 × 1.0
M 6 × 1.0
M 5 × 0.8
M 6 × 1.0
M 4 × 0.7
M 6 × 1.0
M 6 × 1.0
M 6 × 1.0
M 6 × 1.0
M10 × 1.25
M10 × 1.25
M 8 × 1.25
M 6 × 1.0
M10 × 1.0
M10 × 1.0
M 8 × 1.25
M16 × 1.5
M 8 × 1.25
M 6 × 1.0
M 6 × 1.0
M10 × 1.25
M 8 × 1.25
M 6 × 1.0 Handle crown and outer tube
Under bracket and outer tube
Handle crown and steering shaft
Handlebar holder (upper)
Handlebar holder (lower)
Steering ring nut
Front fork and damper assembly
Front fork and adjuster
Damper assembly and base valve
Adjuster and damper assembly
Bleed screw (front fork) and base valve
Front fork and protector
Protector and brake hose holder
Throttle cable cap
Grip cap upper and lower
Clutch lever (nut)
Clutch lever holder
Front brake master cylinder and bracket
Front brake master cylinder cap
Brake lever mounting (bolt)
Brake lever mounting (nut)
Brake lever position locknut
Cable guide (front brake hose) and under bracket
Front brake hose union bolt (master cylinder)
Front brake hose union bolt (caliper)
Front brake caliper and front fork
Front brake caliper and brake hose holder
Brake caliper (front and rear) and pad pin plug
Brake caliper (front and rear) and pad pin
Brake caliper (front and rear) and bleed screw
Front wheel axle and nut
Front wheel axle holder
Front brake disc and wheel hub
Rear brake disc and wheel hub
Footrest bracket and frame
Brake pedal mounting
Rear brake master cylinder and framePart to be tightened Thread size Q’tyTightening torque
Nm m•kg ft•lb
4
4
1
4
2
1
2
2
2
2
2
6
2
2
2
1
2
2
2
1
1
1
1
1
1
2
1
2
2
2
1
4
6
6
4
1
223
20
145
28
40
30
55
29
29
1
7
7
1
4
4
4
9
2
6
6
5
4
30
30
23
10
3
18
6
105
23
12
14
55
26
102.3
2.0
14.5
2.8
4.0
3.0
5.5
2.9
2.9
0.1
0.7
0.7
0.1
0.4
0.4
0.4
0.9
0.2
0.6
0.6
0.5
0.4
3.0
3.0
2.3
1.0
0.3
1.8
0.6
10.5
2.3
1.2
1.4
5.5
2.6
1.0
NOTE:
1. First, tighten the ring nut approximately 38 Nm (3.8 m•kg, 27 ft•lb) by using the ring nut wrench,
then loosen the ring nut one turn.
2. Retighten the ring nut 7 Nm (0.7 m•kg, 5.1 ft•lb).
Refer to NOTE.
1P8-9-31-2 5/19/05 10:30 AM Page 10

2-10
MAINTENANCE SPECIFICATIONSSPEC
M 4 × 0.7
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
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 8 × 1.25
M 5 ×0.8
M 4 ×0.7
M 8 × 1.25
M 6 × 1.0
M 5 ×0.8
M 5 ×0.8
M10 × 1.25
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
M 6 × 1.0
M 6 × 1.0 Rear brake master cylinder cap
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
Chain puller adjust bolt and locknut
Engine mounting:
Engine bracket and frame
Engine and frame (front)
Engine bracket and engine
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 (upper)
Rear frame and frame (lower)
Swingarm and brake hose holder
Swingarm and patch
Drive chain tensioner mounting
Chain support and swingarm
Seal guard and swingarm
Cable guide and frame
Fuel tank mounting boss and frame
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 and fuel tank
Air scoop and panel
Front fender mounting
Rear fender mounting (front)
Rear fender mounting (rear)
Number platePart to be tightened Thread size Q’tyTightening torque
Nm m•kg ft•lb
2
1
1
1
6
72
2
2
2
2
1
1
1
1
1
1
1
1
1
1
2
4
4
2
3
4
2
2
2
2
1
1
4
2
2
4
2
4
2
2
12
30
30
125
42
3
10
7
16
34
64
64
64
85
70
80
80
56
53
32
29
2
2
16
7
6
4
20
10
7
7
7
7
19
7
7
6
7
7
12
70.2
3.0
3.0
12.5
4.2
0.3
1.0
0.7
1.6
3.4
6.4
6.4
6.4
8.5
7.0
8.0
8.0
5.6
5.3
3.2
2.9
0.2
0.2
1.6
0.7
0.6
0.4
2.0
1.0
0.7
0.7
0.7
0.7
1.9
0.7
0.7
0.6
0.7
0.7
1.2
0.71.4
22
22
90
30
2.2
7.2
5.1
11
24
46
46
46
61
50
58
58
40
38
23
21
1.4
1.4
11
5.1
4.3
2.9
14
7.2
5.1
5.1
5.1
5.1
13
5.1
5.1
4.3
5.1
5.1
8.7
5.1
NOTE:
- marked portion shall be checked for torque tightening after break-in or before each race.
1P8-9-31-2 5/19/05 10:30 AM 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 or
Replaceequivalent oil
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 “S1”
Replace oil seal
FRONT FORK OIL SEAL AND DUST SEAL
Clean and lubeLithium base grease
PROTECTOR GUIDE
Replace
REAR SHOCK ABSORBER
(After
Inspect and adjustrain ride)
Lube Molybdenum disulfide grease
Replace spring seatEvery one year
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
After
break-
inEvery
raceEvery
thirdEvery
fifthAs re-
quired
1P8-9-31-3A 5/13/05 11:42 AM Page 3

3-4
PRE-OPERATION INSPECTION AND MAINTENANCE
INSP
ADJ
EC320000
PRE-OPERATION INSPECTION AND MAINTENANCE
Before riding for break-in operation, practice or a race, make sure the machine is in good operating
condition.
Before using this machine, check the following points.
EC321000
GENERAL INSPECTION AND MAINTENANCE
Item Routine Page
Coolant Check that coolant is filled up to the radiator filler cap.
Check the cooling system for leakage.P3-5~9
Fuel Check that a fresh mixture of oil and gasoline is filled in
the fuel tank. Check the fuel line for leakage.P1-12
Transmission oil Check that the oil level is correct. Check the crankcase
for leakage.P3-12~14
Gear shifter and clutch Check that gears can be shifted correctly in order and
that the clutch operates smoothly.P3-9
Throttle grip/Housing Check that the throttle grip operation and free play
are correctly adjusted. Lubricate the throttle grip and P3-10~11
housing, if necessary.
Brakes Check the play of front brake and effect of front and
rear brake.P3-17~23
Chain Check chain slack and alignment. Check that the chain
is lubricated properly.P3-24~26
Wheels Check for excessive wear and tire pressure. Check for
loose spokes and have no excessive play.P3-34~35
Steering Check that the handlebar can be turned smoothly and
have no excessive play.P3-35~36
Front forks and Check that they operate smoothly and there is no oil
rear shock absorber leakage.P3-26~33
Cables (wires) Check that the clutch and throttle cables move smooth-
ly. Check that they are not caught when the handlebars —
are turned or when the front forks travel up and down.
Muffler Check that the muffler is tightly mounted and has no
cracks.P3-15~16
Sprocket Check that the driven sprocket tightening bolt is
not loose.P3-24
Lubrication Check for smooth operation. Lubricate if necessary. P3-37
Bolts and nuts Check the chassis and engine for loose bolts and nuts. P1-16
Lead connectors Check that the CDI magneto, CDI unit, and ignition coil
are connected tightly.P1-6
Settings Is the machine set suitably for the condition of the
racing course and weather or by taking into account the
P7-1~23
results of test runs before racing? Are inspection and
maintenance completely done?
1P8-9-31-3A 5/13/05 11:42 AM Page 14

3-21
REAR BRAKE PAD INSPECTION AND REPLACEMENT
INSP
ADJ
3. Inspect:
9Brake fluid level
Refer to “BRAKE FLUID LEVEL
INSPECTION” section.
4. Check:
9Brake lever operation
A softy or spongy feeling Bleed brake
system.
Refer to “BRAKE SYSTEM AIR BLEED-
ING” section.
EC366060
REAR BRAKE PAD INSPECTION AND
REPLACEMENT
1. Inspect:
9Brake pad thickness a
Out of specification Replace as a set.
2. Replace:
9Brake pad
9Install the pad pin plug 0.
Pad pin plug:
3 Nm (0.3 m•kg, 2.2 ft•lb)
Brake pad thickness a a
:
Standard
6.4 mm (0.25 in)
1.0 mm (0.04 in)
Brake pad replacement steps:
9Remove the protector 1and pad pin plug
2.
9Loosen the pad pin 3.
9Remove the rear wheel 4and caliper 5.
Refer to “FRONT WHEEL AND REAR
WHEEL” section in the CHAPTER 5.
1P8-9-31-3B 5/13/05 11:44 AM Page 6

3-22
REAR BRAKE PAD INSPECTION AND REPLACEMENT
INSP
ADJ
9Remove the pad pin 6and brake pads 7.
9Connect the transparent hose 8to the
bleed screw 9and place the suitable con-
tainer under its end.
9Loosen the bleed screw and push the
caliper piston in.
cC
Do not reuse the drained brake fluid.
9Tighten the bleed screw.
9Install the brake pads 0and pad pin q.
NOTE:
9Install the brake pads with their projections
ainto the caliper recesses b.
9Temporarily tighten the pad pin at this point.
9Install the caliper wand rear wheel e.
Refer to “FRONT WHEEL AND REAR
WHEEL” section in the CHAPTER 5.
9Tighten the pad pin r.
9Install the pad pin plug tand protector y.
Bleed screw:
6 Nm (0.6 m•kg, 4.3 ft•lb)
Pad pin:
18 Nm (1.8 m•kg, 13 ft•lb)
Pad pin plug:
3 Nm (0.3 m•kg, 2.2 ft•lb)
Bolt (protector):
7 Nm (0.7 m•kg, 5.1 ft•lb)
3. Inspect:
9Brake fluid level
Refer to “BRAKE FLUID LEVEL
INSPECTION” section.
4. Check:
9Brake pedal operation
A softy or spongy feeling Bleed brake
system.
Refer to “BRAKE SYSTEM AIR BLEEDING”
section.
1P8-9-31-3B 5/13/05 11:44 AM Page 8

3-25
DRIVE CHAIN SLACK ADJUSTMENT
INSP
ADJ
EC36A061
DRIVE CHAIN SLACK ADJUSTMENT
1. Elevate the rear wheel by placing the suit-
able stand under the engine.
2. Check:
9Drive chain slack a
Above the seal guard installation bolt.
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 tightest point. Check
and/or adjust chain slack with rear wheel in this
“tight chain” position.
Drive chain slack:
48~58 mm (1.9~2.3 in)
Drive chain lubricant:
SAE 10W-30 motor oil or suitable
chain lubricants
5. Install:
9Drive chain 1
9Joint 2
9Master link clip 3
cC
Be sure to install the master link clip to the
direction as shown.
aTurning direction
6. Lubricate:
9Drive chain
4. Check:
9Drive chain stiffness a
Clean and oil the chain and hold as
illustrated.
StiffReplace drive chain.
1P8-9-31-3B 5/13/05 11:44 AM Page 14