2001 YAMAHA YZ250F clock

4 - 25
ENGCAMSHAFTS
CAUTION:
Do not turn the crankshaft during the
camshaft installation. Damage or
improper valve timing will result.
lInstall the clips, camshaft caps 4 and
bolts (camshaft cap) 5.
T R..
Bolt (camshaft cap):
10 Nm (1.0 m • kg, 7.2 ft • lb)
NOTE:
lBefore removing the clips, cover the cylin-
der head with a clean rag to prevent the
clips from into the cylinder head cavity.
lApply the engine oil on the thread and con-
tact surface of the bolts (camshaft cap).
lTighten the bolts (camshaft cap) 5 in a
crisscross pattern.
CAUTION:
The bolts (camshaft cap) must be tight-
ened evenly or damage to the cylinder
head, camshaft caps and camshaft will
result.
2. Install:
lTiming chain tensioner
Installation steps:
lWhile pressing the tensioner rod lightly
with fingers, use a thin screwdriver and
wind the tensioner rod up fully clockwise.
lWith the rod fully wound and the chain
tensioner UP mark a facing upward,
install the gasket 1 and the timing chain
tensioner 2, and tighten the bolt 3 to the
specified torque.
T R..
Bolt (timing chain tensioner):
10 Nm (1.0 m • kg, 7.2 ft • lb)

4 - 26
ENG
lRelease the screwdriver, check the ten-
sioner rod to come out and tighten the
gasket 4 and the cap bolt 5 to the speci-
fied torque.
T R..
Tensioner cap bolt:
7 Nm (0.7 m • kg, 5.1 ft • lb)
3. Turn:
lCrankshaft
Counterclockwise several turns
4. Check:
lRotor T.D.C. mark
Align with the crankcase align mark.
lCamshaft match marks
Align with the cylinder head surface.
Out of alignment ® Adjust.
5. Install:
lTiming mark accessing screw 1
lCrankshaft end accessing screw 2
6. Install:
lTiming chain guide (top side) 1
lCylinder head cover gasket 2
lCylinder head cover 3
lBolt (cylinder head cover) 4
NOTE:
Apply the sealant on the cylinder head cover
gasket.
Quick gasket®:
ACC-QUICK-GS-KT
YAMAHA Bond No. 1215:
90890-85505
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)
CAMSHAFTS

4 - 72
ENGKICK SHAFT AND SHIFT SHAFT
REMOVAL POINTS
Kick shaft assembly
1. Remove:
lKick shaft assembly 1
NOTE:
Unhook the torsion spring 2 from the hole a
in the crankcase.
EC4C3101
Shift guide and shift lever assembly
1. Remove:
lBolt (shift guide)
lShift guide 1
lShift lever assembly 2
NOTE:
The shift lever assembly is disassembled at
the same time as the shift guide.
EC4N3100
Segment
1. Remove:
lBolt (segment) 1
lSegment 2
NOTE:
Turn the segment counterclockwise until it
stops and loosen the bolt.
INSPECTION
Kick shaft and ratchet wheel
1. Check:
lRatchet wheel 1 smooth movement
Unsmooth movement ® Replace.
lKick shaft 2
Wear/damage ® Replace.
lSpring 3
Broken ® Replace.
EC4C4300
Kick gear, kick idle gear and ratchet wheel
1. Inspect:
lKick gear 1
lKick idle gear 2
lRatchet wheel 3
lGear teeth a
lRatchet teeth b
Wear/damage ® Replace.

4 - 76
ENGKICK SHAFT AND SHIFT SHAFT
2. Install:
lTorsion spring 1
To kick shaft 2.
NOTE:
Make sure the stopper a of the torsion spring
fits into the hole b on the kick shaft.
3. Install:
lSpring guide 1
NOTE:
Slide the spring guide into the kick shaft, make
sure the groove a in the spring guide fits on
the stopper of the torsion spring.
4. Install:
lKick shaft assembly 1
lWasher 2
NOTE:
lApply the engine oil on the kick shaft.
lSlide the kick shaft assembly into the crank-
case, make sure the kick shaft stopper a fit
into their home position 3.
5. Hook:
lTorsion spring 1
NOTE:
Turn the torsion spring clockwise and hook
into the proper hole a in the crankcase.
Kick idle gear
1. Install:
lKick idle gear 1
lWasher 2
lCirclip 3
NOTE:
lApply the engine oil on the kick idle gear
inner circumference.
lInstall the kick idle gear with its depressed
side a toward you.

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ENGCDI MAGNETO
EC4L3000
REMOVAL POINTS
Rotor
1. Remove:
lNut (rotor) 1
lWasher 2
Use the rotor holding tool 3.
2. Remove:
lRotor 1
Use the flywheel puller 2.
NOTE:
When installing the flywheel puller, turn it
counterclockwise.
Rotor holding tool:
YU-1235/90890-01235
Flywheel puller:
YM-1189/90890-01189
EC4L4000
INSPECTION
EC4L4101
CDI magneto
1. Inspect:
lRotor inner surface a
lStator outer surface b
Damage ® Inspect the crankshaft
runout and crankshaft bearing.
If necessary, replace CDI magneto and/
or stator.
EC4L4200
Woodruff key
1. Inspect:
lWoodruff key 1
Damage ® Replace.

7 - 21
TUNSETTING
EC72H002
Suspension setting
lFront fork
NOTE:
lIf any of the following symptoms is experienced with the standard position as the base, make
resetting by reference to the adjustment procedure given in the same chart.
lBefore any change, set the rear shock absorber sunken length to the standard figure 90 ~
100 mm (3.5 ~ 3.9 in).
SymptomSection
Check Adjust
JumpLarge
gapMedium
gapSmall
gap
Stiff over entire range
CCC
Compression damping
Oil level (oil amount)
SpringTurn adjuster counterclockwise (about 2 clicks) to
decrease damping.
Decrease oil level by about 5 ~ 10 mm (0.2 ~ 0.4 in).
Replace with soft spring.
Unsmooth movement
over entire range
CCCC
Outer tube
Inner tube
Under bracket tightening
torqueCheck for any bends, dents, and other noticeable
scars, etc. If any, replace affected parts.
Retighten to specified torque.
Poor initial
movement
C
Rebound damping
Oil sealTurn adjuster counterclockwise (about 2 clicks) to
decrease damping.
Apply grease in oil seal wall.
Soft over entire range,
bottoming out
CC
Compression damping
Oil level (oil amount)
SpringTurn adjuster clockwise (about 2 clicks) to increase
damping.
Increase oil level by about 5 ~ 10 mm (0.2 ~ 0.4 in).
Replace with stiff spring.
Stiff toward stroke end
COil level (oil amount) Decrease oil level by about 5 mm (0.2 in).
Soft toward stroke end,
bottoming out
COil level (oil amount) Increase oil level by about 5 mm (0.2 in).
Stiff initial movement
CCCCCompression dampingTurn adjuster counterclockwise (about 2 clicks) to
decrease damping.
Low front, tending to
lower front posture
CC
Compression damping
Rebound damping
Balance with rear end
Oil level (oil amount)Turn adjuster clockwise (about 2 clicks) to increase
damping.
Turn adjuster counterclockwise (about 2 clicks) to
decrease damping.
Set sunken length for 95 ~ 100 mm (3.7 ~ 3.9 in) when
one passenger is astride seat (lower rear posture).
Increase oil level by about 5 mm (0.2 in).
“Obtrusive” front, tend-
ing to upper front pos-
ture
CC
Compression damping
Balance with rear end
Spring
Oil lever (oil amount)Turn adjuster counterclockwise (about 2 clicks) to
decrease damping.
Set sunken length for 90 ~ 95 mm (3.5 ~ 3.7 in) when
one passenger is astride seat (upper rear posture).
Replace with soft spring.
Decrease oil level by about 5 ~ 10 mm (0.2 ~ 0.4 in).

7 - 22
TUNSETTING
lRear shock absorber
NOTE:
lIf any of the following symptoms is experienced with the standard position as the base, make
resetting by reference to the adjustment procedure given in the same chart.
lAdjust the rebound damping in 2-click increments or decrements.
lAdjust the low compression damping in 1-click increments or decrements.
lAdjust the high compression damping in 1/6 turn increments or decrements.
SymptomSection
Check Adjust
JumpLarge
gapMedium
gapSmall
gap
Stiff, tending to sink
CC
Rebound damping
Spring set lengthTurn adjuster counterclockwise (about 2 clicks) to
decrease damping.
Set sunken length for 90 ~ 100 mm (3.5 ~ 3.9 in) when
one passenger is astride seat.
Spongy and unstable
CC
Rebound damping
Low compression damping
SpringTurn adjuster clockwise (about 2 clicks) to increase
damping.
Turn adjuster clockwise (about 1 click) to increase
damping.
Replace with stiff spring.
Heavy and dragging
CC
Rebound damping
SpringTurn adjuster counterclockwise (about 2 clicks) to
decrease damping.
Replace with soft spring.
Poor road gripping
C
Rebound damping
Low compression damping
High compression damp-
ing
Spring set length
SpringTurn adjuster counterclockwise (about 2 clicks) to
decrease damping.
Turn adjuster clockwise (about 1 clicks) to increase
damping.
Turn adjuster clockwise (about 1/6 clicks) to increase
damping.
Set sunken length for 90 ~ 100 mm (3.5 ~ 3.9 in) when
one passenger is astride seat.
Replace with soft spring.
Bottoming out
CC
High compression damp-
ing
Spring set length
SpringTurn adjuster clockwise (about 1/6 turn) to increase
damping.
Set sunken length for 90 ~ 100 mm (3.5 ~ 3.9 in) when
one passenger in astride seat.
Replace with stiff spring.
Bouncing
CC
Rebound damping
SpringTurn adjuster clockwise (about 2 clicks) to increase
damping.
Replace with soft spring.
Stiff travel
CC
High compression damp-
ing
Spring set length
SpringTurn adjuster counterclockwise (about 1/6 turn) to
decrease damping.
Set sunken length for 90 ~ 100 mm (3.5 ~ 3.9 in) when
one passenger is astride seat.
Replace with soft spring.