2002 YAMAHA WR 426F coolant reservoir

2 - 16
SPECMAINTENANCE SPECIFICATIONS (WR426F)
NOTE:
- marked portion shall be checked for torque tightening after break-in or before each race.Part to be tightened Thread size Q’tyTightening torque
Nm m·kg ft·lb
Rear wheel axle and nut M20 × 1.5 1 125 12.5 90
Driven sprocket and wheel hub M8 × 1.25 6 42 4.2 30
Nipple (spoke)—72 3 0.3 2.2
Disc cover and rear brake caliper M6 × 1.0 2 7 0.7 5.1
Protector and rear brake caliper M6 × 1.0 2 7 0.7 5.1
Engine mounting:
Engine bracket and frame M8 × 1.25 7 34 3.4 24
Engine and frame (front) M10 × 1.25 1 69 6.9 50
Engine and frame (upper) M10 × 1.25 1 55 5.5 40
Engine and frame (lower) M10 × 1.25 1 69 6.9 50
Engine guard (left and right) M8 × 1.25 2 23 2.3 17
Pivot shaft and nut M16 × 1.5 1 85 8.5 61
Relay arm and swingarm M14 × 1.5 1 80 8.0 58
Relay arm and connecting rod M14 × 1.5 1 80 8.0 58
Connecting rod and frame M14 × 1.5 1 80 8.0 58
Rear shock absorber and frame M10 × 1.25 1 56 5.6 40
Rear shock absorber and relay arm M10 × 1.25 1 53 5.3 38
Rear frame and frame M8 × 1.25 3 29 2.9 21
Swingarm and brake hose holder M5 × 0.8 4 1 0.1 0.7
Swingarm and patch M4 × 0.7 4 2 0.2 1.4
Drive chain tensioner mounting (upper) M8 × 1.25 1 19 1.9 13
Drive chain tensioner mounting (lower) M8 × 1.25 1 20 2.0 14
Chain support and swingarm M6 × 1.0 3 7 0.7 5.1
Seal guard and swingarm M5 × 0.8 4 6 0.6 4.3
Fuel tank mounting M6 × 1.0 2 10 1.0 7.2
Fuel tank and fuel cock M6 × 1.0 2 7 0.7 5.1
Fuel tank and seat set bracket M6 × 1.0 1 7 0.7 5.1
Fuel tank and hooking screw (fitting band) M6 × 1.0 1 7 0.7 5.1
Fuel tank and fuel tank bracket M6 × 1.0 4 7 0.7 5.1
Seat mounting M8 × 1.25 2 23 2.3 17
Side cover mounting M6 × 1.0 2 7 0.7 5.1
Air scoop and fuel tank M6 × 1.0 4 4 0.4 2.9
Air scoop and radiator panel (lower) M6 × 1.0 2 4 0.4 2.9
Front fender mounting M6 × 1.0 4 7 0.7 5.1
Rear fender and air filter case M6 × 1.0 2 7 0.7 5.1
Rear fender and frame (right) M6 × 1.0 1 10 1.0 7.2
Headlight stay (lower) and under bracket M8 × 1.25 2 7 0.7 5.1
Headlight (left and right) M6 × 1.0 2 10 1.0 7.2
Headlight (lower) M6 × 1.0 1 7 0.7 5.1
Tail light M6 × 1.0 3 4 0.4 2.9
Tail light lead clamp and rear fender M4 × 1.59 2 1 0.1 0.7
Coolant reservoir tank (front) M6 × 1.0 1 7 0.7 5.1
Coolant reservoir tank (rear) M6 × 1.0 1 11 1.1 8.0
Sidestand bracket and frame M10 × 1.25 2 66 6.6 48
Sidestand mounting M10 × 1.25 1 64 6.4 46

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SPECMAINTENANCE SPECIFICATIONS (WR400F)
NOTE:
- marked portion shall be checked for torque tightening after break-in or before each race.Part to be tightened Thread size Q’tyTightening torque
Nm m·kg ft·lb
Rear wheel axle and nut M20 × 1.5 1 125 12.5 90
Driven sprocket and wheel hub M8 × 1.25 6 42 4.2 30
Nipple (spoke)—72 3 0.3 2.2
Disc cover and rear brake caliper M6 × 1.0 2 7 0.7 5.1
Protector and rear brake caliper M6 × 1.0 2 7 0.7 5.1
Engine mounting:
Engine bracket and frame M8 × 1.25 7 34 3.4 24
Engine and frame (front) M10 × 1.25 1 69 6.9 50
Engine and frame (upper) M10 × 1.25 1 55 5.5 40
Engine and frame (lower) M10 × 1.25 1 69 6.9 50
Engine guard (left and right) M8 × 1.25 2 23 2.3 17
Pivot shaft and nut M16 × 1.5 1 85 8.5 61
Relay arm and swingarm M14 × 1.5 1 80 8.0 58
Relay arm and connecting rod M14 × 1.5 1 80 8.0 58
Connecting rod and frame M14 × 1.5 1 80 8.0 58
Rear shock absorber and frame M10 × 1.25 1 56 5.6 40
Rear shock absorber and relay arm M10 × 1.25 1 53 5.3 38
Rear frame and frame M8 × 1.25 3 29 2.9 21
Swingarm and brake hose holder M5 × 0.8 4 1 0.1 0.7
Swingarm and patch M4 × 0.7 4 2 0.2 1.4
Drive chain tensioner mounting (upper) M8 × 1.25 1 19 1.9 13
Drive chain tensioner mounting (lower) M8 × 1.25 1 20 2.0 14
Chain support and swingarm M6 × 1.0 3 7 0.7 5.1
Seal guard and swingarm M5 × 0.8 4 6 0.6 4.3
Fuel tank mounting M6 × 1.0 2 10 1.0 7.2
Fuel tank and fuel cock M6 × 1.0 2 7 0.7 5.1
Fuel tank and seat set bracket M6 × 1.0 1 7 0.7 5.1
Fuel tank and hooking screw (fitting band) M6 × 1.0 1 7 0.7 5.1
Fuel tank and fuel tank bracket M6 × 1.0 4 7 0.7 5.1
Seat mounting M8 × 1.25 2 23 2.3 17
Side cover mounting M6 × 1.0 2 7 0.7 5.1
Air scoop and fuel tank M6 × 1.0 4 4 0.4 2.9
Air scoop and radiator panel (lower) M6 × 1.0 2 4 0.4 2.9
Front fender mounting M6 × 1.0 4 7 0.7 5.1
Rear fender and air filter case M6 × 1.0 2 7 0.7 5.1
Rear fender and frame (right) M6 × 1.0 1 10 1.0 7.2
Headlight stay (lower) and under bracket M8 × 1.25 2 7 0.7 5.1
Headlight (left and right) M6 × 1.0 2 10 1.0 7.2
Headlight (lower) M6 × 1.0 1 7 0.7 5.1
Tail light M6 × 1.0 3 4 0.4 2.9
Tail light lead clamp and rear fender M4 × 1.59 2 1 0.1 0.7
Coolant reservoir tank (front) M6 × 1.0 1 7 0.7 5.1
Coolant reservoir tank (rear) M6 × 1.0 1 11 1.1 8.0
Sidestand bracket and frame M10 × 1.25 2 66 6.6 48
Sidestand mounting M10 × 1.25 1 64 6.4 46

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SPECCABLE ROUTING DIAGRAM
EC240000
CABLE ROUTING DIAGRAM
1Hose guide
2Brake hose
3Regulator
4Fuel tank breather hose
5Oil tank breather hose
6Clamp
7Sub wire harness
8Tail light lead
9TPS (throttle position sensor) lead
0Neutral switch lead
AOil hose
BCylinder head breather hose
CHose holder
DCDI magneto lead
EClutch cable
FDecompression cable
GLights switch lead
HCarburetor breather hose
IOverflow hose
JCoolant reservoir tank breather hoseÅPass the fuel tank breather
hose behind handlebar, then
insert it into the steering shaft
hole.
ıPass the decompression
cable, regulator lead and lights
switch lead under where the oil
hose is attached.
ÇFasten the CDI magneto lead,
neutral switch lead and lights
switch lead to the frame with a
plastic locking tie.
ÎFasten the sub wire harness
and lights switch lead to the
frame in front of the protector
of the sub wire harness with a
plastic locking tie and cut off
the tie end.‰Pass the cylinder head
breather hose along the right
side of the oil tank breather
hose.
ÏFasten the sub wire harness
to the frame with a plastic
locking tie ends at the lower
left of the frame and cut off
the tie end. For fastening,
pass the plastic locking tie
through the upper holes in the
engine brackets.
ÌPass the sub wire harness
between the engine brackets.
ÓFasten the TPS lead (in the
sub wire harness) under the
frame so that it does not con-
tact the carburetor.

2 - 39
SPECCABLE ROUTING DIAGRAM
ÈMake sure that the TPS read
coupler does not go outside
the chassis.
ÔFasten the TPS lead under the
coupler to the frame with a
plastic locking tie.
Pass the carburetor breather
hoses and overflow hose
between the connecting rod
and cross tube (frame).
ÒFasten the neutral switch lead
and oil hose together with a
plastic locking tie and cut off
the tie end.
˜Fasten the cylinder head
breather hose with the hose
holder.
ˆFasten the neutral switch lead
to the frame with a plastic
band ends toward the rear of
the frame.ØFasten the neutral switch lead
and CDI magneto lead
together with a plastic band.
∏Pass the clutch cable through
the cable guide.
ŒPass the cylinder head
breather hose along the inner
side of the radiator pipe.
ÂPass the clutch cable between
the frame and radiator and
over the lower boss on the
radiator.
ÍPass the neutral switch lead
and CDI magneto lead through
the cable guide and over the
middle radiator mounting boss.
Then, pass the decompression
cable under the middle radia-
tor mounting boss and along
the left side of the neutral
switch lead and CDI magneto
lead.ÊPass the clutch cable through
the cable guide.
ËFit the brake hose into the
guides on the protector.
◊Fasten the ignition coil lead
(in the sub wire harness) on
the upper inside of the frame
and cut off the tie end.
„Pass the ignition coil lead (in
the sub wire harness) under
the cushion bracket (frame).
≈Fasten the ignition coil lead
(in the sub wire harness) to
the frame with a plastic lock-
ing tie and cut off the tie end.
ÁPass the carburetor breather
hoses, overflow hose and
coolant reservoir tank
breather hose so that all there
hoses do not contact the rear
shock absorber.

2 - 40
SPECCABLE ROUTING DIAGRAM
1Coolant reservoir tank
breather hose
2Clamp
3Ignition coil
4High tension cord
5CDI unit
6CDI unit band
7“ENGINE STOP” button
lead
8Throttle cable (pull)
9Throttle cable (return)
0Radiator (left)
ARadiator (right)
BDecompression cable
CCDI unit stay (frame)ÅFasten the coolant reservoir tank
breather hose and carburetor
breather hoses together with a
plastic locking tie.
ıFasten the ignition coil lead to the
frame with a plastic band.
ÇPass the ignition coil lead (in the
sub wire harness) so that it does
not contact the carburetor and
rear shock absorber and connect
it with the lead from the ignition
coil on the inside of the frame.
ÎFasten the ignition coil and
ground lead to the frame with the
bolt.
‰Pass the throttle cables over the
high tension cord.
ÏPass the throttle cables along the
outer side of the CDI unit leads.ÌFasten the CDI unit leads and
“ENGINE STOP” button lead to
the frame at the protector of the
CDI unit leads with a plastic lock-
ing tie.
ÓFit the boot over the coupler.
ÈPass the throttle cables between
the top radiator mounting boss
and middle radiator mounting
boss.
ÔPass the CDI unit lead and
“ENGINE STOP” button lead over
the top radiator mounting boss.
Pass the throttle cables and
“ENGINE STOP” button lead
through the cable guide.
ÒCross the pull and return throttle
cables before the radiator.
˜Insert the CDI unit band over the
CDI unit stay (frame) as far as
possible.

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SPEC
1Coolant reservoir hose
2Coolant reservoir tank breather hose
3Clamp
4Tail light lead
5Hose guideÅFasten the coolant reservoir hose and coolant
reservoir tank breather hose.
ıDo not allow the tail light lead to slacken.
ÇPass the coolant reservoir hose and coolant res-
ervoir tank breather hose through the hose
guide.
CABLE ROUTING DIAGRAM

3 - 4
INSP
ADJ
PRE-OPERATION INSPECTION AND MAINTENANCE
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.
GENERAL INSPECTION AND MAINTENANCE
Item Routine Page
CoolantCheck that coolant is filled up to the radiator filler cap.
Check that the coolant level is correct in the coolant reservoir
tank.
Check the cooling system for leakage.P.3-5 ~ 9
FuelCheck that a fresh gasoline is filled in the fuel tank. Check the
fuel line for leakage.P.1-14
Engine oilCheck that the oil level is correct. Check the crankcase and
frame oil line for leakage.P.3-14 ~ 18
Gear shifter and clutchCheck that gears can be shifted correctly in order and that the
clutch operates smoothly.P.3-10
Throttle grip/HousingCheck that the throttle grip operation and free play are correctly
adjusted. Lubricate the throttle grip and housing, if necessary.P.3-10 ~ 11
Brakes Check the play of front brake and effect of front and rear brake. P.3-26 ~ 32
ChainCheck chain slack and alignment. Check that the chain is lubri-
cated properly.P.3-33 ~ 36
WheelsCheck for excessive wear and tire pressure. Check for loose
spokes and have no excessive play.P.3-44 ~ 45
SteeringCheck that the handlebar can be turned smoothly and have no
excessive play.P.3-45 ~ 46
Front forks and rear shock
absorberCheck that they operate smoothly and there is no oil leakage. P.3-36 ~ 43
Cables (wires)Check that the clutch and throttle cables move smoothly. 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.—
Sprocket Check that the driven sprocket tightening bolt is not loose. P.3-33
Lubrication Check for smooth operation. Lubricate if necessary. P.3-47
Bolts and nuts Check the chassis and engine for loose bolts and nuts. P.1-19
Lead connectorsCheck that the CDI magneto, CDI unit, and ignition coil are con-
nected tightly.P.1-6
SettingsIs the machine set suitably for the condition of the racing course
and weather or by taking into account the results of test runs
before racing? Are inspection and maintenance completely
done?P.7-1 ~ 22

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INSP
ADJ
COOLANT REPLACEMENT
CAUTION:
Take care so that coolant does not splash
on painted surfaces. If it splashes, wash it
away with water.
1. Place a container under the engine.
2. Remove:
Seat
Refer to ”SEAT FUEL TANK AND SIDE
COVERS” section in the CHAPTER 4.
3. Disconnect:
Coolant reservoir hose 1
Drain the coolant completely.
4. Connect:
Coolant reservoir hose
LOWFULLCOOLANT1
5. Remove:
Engine guard 1
Coolant drain bolt 2
6. Remove:
Radiator cap
Drain the coolant completely.
7. Clean:
Cooling system
Thoroughly flush the cooling system
with clean tap water.
8. Install:
Copper washer
Coolant drain bolt
Engine guard
Bolt [engine guard (front)]
Bolt [engine guard (rear)]
New
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)
T R..34 Nm (3.4 m · kg, 24 ft · lb)
T R..23 Nm (2.3 m · kg, 17 ft · lb)