coolant reservoir YAMAHA WR 426F 2001 Manuale duso (in Italian)

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 brake hose union bolt (master cylinder)M10 ´ 1.25 1 30 3.0 22
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 ´ — 4 4 0.4 2.9
Drive chain tensioner mounting M8 ´ 1.25 2 19 1.9 13
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 mounting M6 ´ 1.0 4 7 0.7 5.1
Headlight stay (under) and under bracket M6 ´ 1.0 2 7 0.7 5.1
Headlight M6 ´ 1.0 3 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 M6 ´ 1.0 2 7 0.7 5.1
Sidestand bracket and frame M10 ´ 1.25 2 64 6.4 46
Sidestand mounting M10 ´ 1.25 1 64 6.4 46

2 - 33
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 brake hose union bolt (master cylinder)M10 ´ 1.25 1 30 3.0 22
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 ´ — 4 4 0.4 2.9
Drive chain tensioner mounting M8 ´ 1.25 2 19 1.9 13
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 mounting M6 ´ 1.0 4 7 0.7 5.1
Headlight stay (under) and under bracket M6 ´ 1.0 2 7 0.7 5.1
Headlight M6 ´ 1.0 3 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 M6 ´ 1.0 2 7 0.7 5.1
Sidestand bracket and frame M10 ´ 1.25 2 64 6.4 46
Sidestand mounting M10 ´ 1.25 1 64 6.4 46

2 - 38
SPEC

CABLE ROUTING DIAGRAM
EC240000
CABLE ROUTING DIAGRAM
1
Hose guide
2
Brake hose
3
Regulator
4
Fuel tank breather hose
5
Oil tank breather hose
6
Clamp
7
“ENGINE STOP” button lead
8
Sub wire harness
9
Tail light lead
0
TPS (throttle position sensor) lead
A
Neutral switch lead
B
Oil hose
C
Cylinder head breather hose
D
CDI magneto lead
E
Hose holder
F
Clutch cable
G
Decompression cable
H
Lights switch lead
I
Carburetor breather hose
J
Overflow hose
K
Coolant reservoir tank breather hose

Pass the fuel tank breather
hose behind handlebar, then
insert it into the steering shaft
hole.
õ
Pass the decompression
cable, “ENGINE STOP” but-
ton lead and lights switch lead
under where the oil hose is
attached.
‚
Fasten the CDI magneto lead,
neutral switch lead “ENGINE
STOP” button lead and lights
switch lead to the frame with a
plastic locking tie.
ë
Pass the “ENGINE STOP” but-
ton lead and lights switch lead
along the inner side of the oil
tank breather hose.
ä
Fasten the sub wire harness,
“ENGINE STOP” button lead
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.
ì
Pass the cylinder head
breather hose along the right
side of the oil tank breather
hose.
í
Fasten the sub wire harness
and “ENGINE STOP” button
lead to the frame with a plas-
tic locking tie and cut off the
tie end.
î
Pass the sub wire harness
between the engine brackets.

2 - 40
SPECCABLE ROUTING DIAGRAM
1Coolant reservoir tank
breather hose
2Clamp
3Ignition coil
4High tension cord
5CDI unit
6CDI unit band
7Radiator (left)
8Radiator (right)
9Decompression cable
0CDI unit stay (frame)Fasten the coolant reservoir tank
breather hose and carburetor
breather hose together with a
plastic locking tie.
õFasten the ignition coil lead to the
frame with a plastic band.
‚Pass 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.
ëFasten the ignition coil and
ground lead to the frame with the
bolt.
äPass the throttle cables over the
high tension cord.ìPass the throttle cables along the
outer side of the CDI unit leads.
íUsing a plastic locking tie, clamp
to the frame the CDI unit leads at
their protecting tubes.
îFit the boot over the coupler.
éPass the throttle cables between
the top radiator mounting boss
and middle radiator mounting
boss.
ïPass the CDI unit leads over the
top radiator mounting boss.
ðCross the pull and return throttle
cables before the radiator.
ñPass the throttle cables through
the cable guide.
÷Insert the CDI unit band over the
CDI unit stay (frame) as far as
possible.

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.1-13
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 ~ 35
WheelsCheck for excessive wear and tire pressure. Check for loose
spokes and have no excessive play.P.3-42 ~ 44
SteeringCheck that the handlebar can be turned smoothly and have no
excessive play.P.3-44 ~ 45
Front forks and rear shock
absorberCheck that they operate smoothly and there is no oil leakage. P.3-35 ~ 42
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.3-46
Bolts and nuts Check the chassis and engine for loose bolts and nuts. P.1-18
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

3 - 6
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:
l
Seat
Refer to ”SEAT FUEL TANK AND SIDE
COVERS” section in the CHAPTER 4.
3. Disconnect:
l
Coolant reservoir hose
1

Drain the coolant completely.
4. Connect:
l
Coolant reservoir hose
LOWFULLCOOLANT1

5. Remove:
l
Engine guard
1

l
Coolant drain bolt
2

6. Remove:
l
Radiator cap
Drain the coolant completely.
7. Clean:
l
Cooling system
Thoroughly flush the cooling system
with clean tap water.
8. Install:
l
Copper washer
l
Coolant drain bolt
l
Engine guard
l
Bolt [engine guard (front)]
l
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)

3 - 7
INSP
ADJ
COOLANT REPLACEMENT
9. Fill:
lRadiator
lEngine
To specified level.
CAUTION:
lDo not mix more than one type of ethyl-
ene glycol antifreeze containing corro-
sion inhibitors for aluminum engine.
lDo not use water containing impurities or oil.
Recommended coolant:
High quality ethylene glycol
anti-freeze containing
anti-corrosion for
aluminum engine
Coolant 1 and water
(soft water) 2 mixing ratio:
50%/50%
Coolant capacity:
1.2 L (1.06 Imp qt, 1.27 US qt)
Handling notes of coolant:
The coolant is harmful so it should be han-
dled with special care.
WARNING
lWhen coolant splashes to your eye.
Thoroughly wash your eye with water
and see your doctor.
lWhen coolant splashes to your clothes.
Quickly wash it away with water and
then with soap.
lWhen coolant is swallowed.
Quickly make him vomit and take him
to a doctor.
10. Install:
lRadiator cap
11. Fill:
lCoolant reservoir tank
Midway a between maximum and min-
imum marks on the tank.
LOWFULLCOOLANTa

3 - 8
INSP
ADJRADIATOR CAP INSPECTION/
RADIATOR CAP OPENING PRESSURE INSPECTION
12. Install:
lCoolant reservoir cap
13. Start the engine and let it warm up for
several minutes.
14. Turn off the engine and inspect the cool-
ant level.
Refer to “COOLANT LEVEL INSPEC-
TION” section.
NOTE:
Before checking the coolant level wait a few
minutes until the coolant settles.
RADIATOR CAP INSPECTION
1. Inspect:
lSeal (radiator cap) 1
lValve and valve seat 2
Crack/damage ® Replace.
Fur deposits 3 ® Clean or replace.
EC356001
RADIATOR CAP OPENING PRESSURE
INSPECTION
1. Attach:
lRadiator cap tester 1 and adapter 2
NOTE:
Apply water on the radiator cap seal.
3Radiator cap
2. Apply the specified pressure.
Radiator cap tester:
YU-24460-01/90890-01325
Adapter:
YU-33984/90890-01352
Radiator cap opening pressure:
110 kPa (1.1 kg/cm2, 15.6 psi)

ENG

4 - 4
RADIATOR
EC450001
RADIATOR
Extent of removal:
1
Radiator removal
2
Coolant reservoir removal
Extent of removal Order Part name Q’ty Remarks
RADIATOR REMOVAL
Preparation for removal Drain the coolant. Refer to “COOLANT REPLACEMENT”
section in the CHAPTER 3.
Seat, fuel tank and side cover Refer to “SEAT, FUEL TANK AND SIDE
COVERS” section.
Exhaust pipe Refer to “EXHAUST PIPE AND
SILENCER” section.
1 Engine guard (right) 1
2 Panel 2
3 Clamp 8
4 Radiator (right) 1
5 Hose 2 1
6 Hose 3 1
7 Hose 4 1
8 Pipe 2/O-ring 1/1
9 Radiator breather hose 1
10 Radiator (left) 1
1

ENG

4 - 5
RADIATOR
Extent of removal Order Part name Q’ty Remarks
11 Hose 1 1
12 Pipe 1/O-ring 1/1
13 Coolant reservoir hose 1
14Coolant reservoir tank
1
2
1