2001 YAMAHA WR 426F oil filter

CHAPTER 3
REGULAR INSPECTION AND
ADJUSTMENTS
MAINTENANCE INTERVALS
................... 3-1
PRE-OPERATION INSPECTION
AND MAINTENANCE
............................... 3-4
ENGINE
..................................................... 3-5
CHASSIS
................................................. 3-26
ELECTRICAL
.......................................... 3-47
CHAPTER 4
ENGINE
SEAT, FUEL TANK
AND SIDE COVERS
................................. 4-1
EXHAUST PIPE AND SILENCER
............ 4-2
RADIATOR
................................................ 4-4
CARBURETOR
......................................... 4-8
CAMSHAFTS
.......................................... 4-21
CYLINDER HEAD
................................... 4-28
VALVES AND VALVE SPRINGS
........... 4-32
CYLINDER AND PISTON
....................... 4-41
CLUTCH (WR426F)
................................ 4-48
CLUTCH (WR400F)
................................ 4-55
OIL FILTER, WATER PUMP
AND CRANKCASE COVER (RIGHT)
.... 4-62
BALANCER
............................................ 4-69
OIL PUMP
............................................... 4-72
KICK AXLE AND SHIFT SHAFT
............ 4-76
CDI MAGNETO
....................................... 4-83
ENGINE REMOVAL
................................ 4-87
CRANKCASE AND CRANKSHAFT
....... 4-92
TRANSMISSION, SHIFT CAM
AND SHIFT FORK
................................ 4-101

2 - 10
SPEC

MAINTENANCE SPECIFICATIONS (WR426F)
Item Standard
Lubrication chart:
Pressure feed
Splashed scavenge
Oil strainer
Oil pan Oil pump rotor 2
Oil pump rotor 1
Oil tank
Oil filter
Check ball
Cylinder head
Crank pinPiston pinPiston
Drive axleMain axleTransmission gears
Camshaft
Valve lifter

2 - 11
SPEC

MAINTENANCE SPECIFICATIONS (WR426F)
Part to be tightened Thread size Q’tyTightening torque
Nm m·kg ft·lb
Spark plug M10S
´
1.0 1 13 1.3 9.4
Camshaft cap M6
´
1.0 10 10 1.0 7.2
Cylinder head (stud bolt) M6
´
1.0 2 7 0.7 5.1
M8
´
1.25 3 15 1.5 11
(bolt) M10
´
1.25 4 44 4.4 32
(nut) M6
´
1.0 2 10 1.0 7.2
M8
´
1.25 2 20 2.0 14
Cylinder head cover M6
´
1.0 2 10 1.0 7.2
Cylinder M6
´
1.0 1 10 1.0 7.2
Timing chain tensioner M6
´
1.0 2 10 1.0 7.2
Tensioner cap bolt M6
´
1.0 1 7 0.7 5.1
Timing chain guide (rear) M6
´
1.0 2 10 1.0 7.2
Decompression shaft M6
´
1.0 1 7 0.7 5.1
Decompression cable guide M6
´
1.0 1 10 1.0 7.2
Exhaust pipe (nut) M8
´
1.25 1 13 1.3 9.4
(bolt) M8
´
1.25 1 24 2.4 17
Silencer M8
´
1.25 2 35 3.5 25
Silencer clamp M8
´
1.25 1 20 2.0 14
Exhaust pipe protector M6
´
1.0 3 10 1.0 7.2
Spark arrester (for USA) M6
´
1.0 3 10 1.0 7.2
Silencer end pipe (for USA) M6
´
1.0 1 10 1.0 7.2
Clamp (air cleaner joint) M5
´
0.8 1 3 0.3 2.2
Clamp (carburetor joint) M4
´
0.7 1 3 0.3 2.2
Air filter joint clamp M6
´
1.0 1 3 0.3 2.2
Throttle cable cover M5
´
0.8 1 4 0.4 2.9
Air filter element M6
´
1.0 1 2 0.2 1.4
Air filter case cover M6
´
1.0 4 4 0.4 2.9
Radiator panel (upper) M6
´
1.0 2 10 1.0 7.2
Radiator M6
´
1.0 6 10 1.0 7.2
Radiator hose clamp M6
´
1.0 8 2 0.2 1.4
Impeller M8
´
1.25 1 14 1.4 10
Water pump housing cover M6
´ 1.0 3 10 1.0 7.2
Coolant drain bolt M6 ´ 1.0 1 10 1.0 7.2
Oil pump cover M5 ´ 0.8 1 4 0.4 2.9
Oil pump M6 ´ 1.0 3 10 1.0 7.2
Engine oil drain bolt (oil filter) M6 ´ 1.0 1 10 1.0 7.2
Oil filter cover M6 ´ 1.0 2 10 1.0 7.2
Oil delivery pipe 1 M10 ´ 1.25
M8 ´ 1.251
220
182.0
1.814
13
Oil hose clamp — 2 2 0.2 1.4
Clutch cover M6 ´ 1.0 7 10 1.0 7.2
Crankcase cover (right) M6 ´ 1.0 10 10 1.0 7.2
Crankcase cover (left) M6 ´ 1.0 8 10 1.0 7.2
Crankcase M6 ´ 1.0 12 12 1.2 8.7

2 - 27
SPECMAINTENANCE SPECIFICATIONS (WR400F)
Item Standard
Lubrication chart:
Pressure feed
Splashed scavenge
Oil strainer
Oil pan Oil pump rotor 2
Oil pump rotor 1
Oil tank
Oil filter
Check ball
Cylinder head
Crank pinPiston pinPiston
Drive axleMain axleTransmission gears
Camshaft
Valve lifter

2 - 28
SPECMAINTENANCE SPECIFICATIONS (WR400F)
Part to be tightened Thread size Q’tyTightening torque
Nm m·kg ft·lb
Spark plug M10S ´ 1.0 1 13 1.3 9.4
Camshaft cap M6 ´ 1.0 10 10 1.0 7.2
Cylinder head (stud bolt) M6 ´ 1.0 2 7 0.7 5.1
M8 ´ 1.25 3 15 1.5 11
(bolt) M10 ´ 1.25 4 44 4.4 32
(nut) M6 ´ 1.0 2 10 1.0 7.2
M8 ´ 1.25 2 20 2.0 14
Cylinder head cover M6 ´ 1.0 2 10 1.0 7.2
Cylinder M6 ´ 1.0 1 10 1.0 7.2
Timing chain tensioner M6 ´ 1.0 2 10 1.0 7.2
Tensioner cap bolt M6 ´ 1.0 1 7 0.7 5.1
Timing chain guide (rear) M6 ´ 1.0 2 10 1.0 7.2
Decompression shaft M6 ´ 1.0 1 7 0.7 5.1
Decompression cable guide M6 ´ 1.0 1 10 1.0 7.2
Exhaust pipe (nut) M8 ´ 1.25 1 13 1.3 9.4
(bolt) M8 ´ 1.25 1 24 2.4 17
Silencer M8 ´ 1.25 2 35 3.5 25
Silencer clamp M8 ´ 1.25 1 20 2.0 14
Exhaust pipe protector M6 ´ 1.0 3 10 1.0 7.2
Spark arrester (for USA) M6 ´ 1.0 3 10 1.0 7.2
Silencer end pipe (for USA) M6 ´ 1.0 1 10 1.0 7.2
Clamp (air cleaner joint) M5 ´ 0.8 1 3 0.3 2.2
Clamp (carburetor joint) M4 ´ 0.7 1 3 0.3 2.2
Air filter joint clamp M6 ´ 1.0 1 3 0.3 2.2
Throttle cable cover M5 ´ 0.8 1 4 0.4 2.9
Air filter element M6 ´ 1.0 1 2 0.2 1.4
Air filter case cover M6 ´ 1.0 4 4 0.4 2.9
Radiator panel (upper) M6 ´ 1.0 2 10 1.0 7.2
Radiator M6 ´ 1.0 6 10 1.0 7.2
Radiator hose clamp M6 ´ 1.0 8 2 0.2 1.4
Impeller M8 ´ 1.25 1 14 1.4 10
Water pump housing cover M6 ´ 1.0 3 10 1.0 7.2
Coolant drain bolt M6 ´ 1.0 1 10 1.0 7.2
Oil pump cover M5 ´ 0.8 1 4 0.4 2.9
Oil pump M6 ´ 1.0 3 10 1.0 7.2
Engine oil drain bolt (oil filter) M6 ´ 1.0 1 10 1.0 7.2
Oil filter cover M6 ´ 1.0 2 10 1.0 7.2
Oil delivery pipe 1 M10 ´ 1.25
M8 ´ 1.251
220
182.0
1.814
13
Oil hose clamp — 2 2 0.2 1.4
Clutch cover M6 ´ 1.0 7 10 1.0 7.2
Crankcase cover (right) M6 ´ 1.0 10 10 1.0 7.2
Crankcase cover (left) M6 ´ 1.0 8 10 1.0 7.2
Crankcase M6 ´ 1.0 12 12 1.2 8.7

3 - 1
INSP
ADJ

MAINTENANCE INTERVALS
EC300000
REGULAR INSPECTION AND ADJUSTMENTS
MAINTENANCE INTERVALS
The following schedule is intended as a general guide to maintenance and lubrication. Bear in mind
that such factors as weather, terrain, geographical location, and individual usage will alter the
required maintenance and lubrication intervals. If you are a doubt as to what intervals to follow in
maintaining and lubricating your machine, consult your Yamaha dealer.
ItemAfter
break-inEvery
race
Every
third
or
500 km
(300 mi)Every
fifth
or
1,000 km
(600 mi)
As re-
quiredRemarks
ENGINE OIL
Replace
cc
OIL FILTER
Clean
cc
VALVES
Check the valve clearances.
Inspect
Replace
cc
c
c
The engine must be cold.
Check the valve seats and
valve stems for wear.
VALVE SPRINGS
Inspect
Replace
c
c
Check the free length and
the tilt.
VALVE LIFTERS
Inspect
Replace
c
c
Check for scratches and
wear.
CAMSHAFTS
Inspect
Replace
c
c
Inspect the camshaft sur-
face.
CAMSHAFT SPROCKETS
Inspect
Replace
c
c
Check for wear on the
teeth and for damage.
PISTON
Inspect
Clean
Replace
cc
c
c
Inspect crack
Remove carbon
PISTON RING
Inspect
Replace
c
cc
Check ring end gap
PISTON PIN
Inspect
Replace
c
c
CYLINDER HEAD
Inspect and clean
c
Remove carbon
Change gasket
CYLINDER
Inspect and clean
Replace
c
c
Inspect score marks
Inspect wear
CLUTCH
Inspect and adjust
Replace
cc
c
Inspect housing, friction
plate, clutch plate and
spring
TRANSMISSION
Inspect
Replace bearing
c
c


3

3 - 2
INSP
ADJ

MAINTENANCE INTERVALS
SHIFT FORK, SHIFT CAM, GUIDE BAR
Inspect
c
Inspect wear
ROTOR NUT
Retighten
cc
MUFFLER
Inspect and retighten
Clean
Replace
cc
c
c
*Whichever comes first
*SPARK ARRESTER
Clean
(Every
six
months)
c
CRANK
Inspect and clean
cc
CARBURETOR
Inspect, adjust and clean
cc
When using a high-pres-
sure washer, make sure
that water does not enter
the accelerator pump.
SPARK PLUG
Inspect and clean
Replace
cc
c
DRIVE CHAIN
Lubricate, slack, alignment
Replace
cc
c
Use chain lube
Chain slack: 40 ~ 50 mm
(1.6 ~ 2.0 in)
COOLING SYSTEM
Check coolant level and leakage
Check radiator cap operation
Replace coolant
Inspect hoses
cc
cc
c
Every two years
OUTSIDE NUTS AND BOLTS
Retighten
cc
Refer to “STARTING AND
BREAK-IN” section in the
CHAPTER 1.
AIR FILTER
Clean and lubricate
Replace
cc
c
Use foam air-filter oil
OIL STRAINER (frame)
Clean
c
FRAME
Clean and inspect
cc
FUEL TANK, COCK
Clean and inspect
cc
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 fluid
c
c
c
c
cc
c
c
c
c
c
c
Every one year ItemAfter
break-inEvery
race
Every
third
or
500 km
(300 mi)Every
fifth
or
1,000 km
(600 mi)
As re-
quiredRemarks


3

3 - 13
INSP
ADJ
1. Remove:
lSeat
2. Disconnect:
lTail light lead connectors 1
3. Remove:
lAir filter case cover 2
4. Remove:
lFitting bolt 1
lWasher 2
lAir filter element 3
lFilter guide 4
5. Clean:
lAir filter element
Clean them with solvent.
NOTE:
After cleaning, remove the remaining solvent
by squeezing the element.
CAUTION:
lDo not twist the element when squeezing
the element.
lLeaving too much of solvent in the ele-
ment may result in poor starting.
6. Inspect:
lAir filter element
Damage ® Replace.
7. Apply:
lFoam-air-filter oil or engine mixing oil
To the element.
NOTE:
Squeeze out the excess oil. Element should
be wet but not dripping.
8. Install:
lFilter guide 1
NOTE:
Align the projection a on filter guide with the
hole b in air filter element.
AIR FILTER CLEANING