2002 YAMAHA WR 426F engine oil

2 - 2
SPECGENERAL SPECIFICATIONS (WR426F)
Oil capacity:
Engine oil
Periodic oil change 1.3 L (1.14 Imp qt, 1.37 US qt)
With oil filter replacement 1.4 L (1.23 Imp qt, 1.48 US qt)
Total amount 1.5 L (1.32 Imp qt, 1.59 US qt)
Coolant capacity (including all routes): 1.2 L (1.06 Imp qt, 1.27 US qt)
Air filter: Wet type element
Fuel:
Type Premium unleaded gasoline only with a
research octane number of 95 or higher.
(Except for ZA)
Premium gasoline (For ZA)
Tank capacity 12 L (2.64 Imp gal, 3.17 US gal)
(For USA, CDN, AUS and NZ)
8.0 L (1.76 Imp gal, 2.11 US gal)
(For EUROPE and ZA)
Reserve 1.6 L (0.35 Imp gal, 0.42 US gal)
(For USA, CDN, AUS and NZ)
1.4 L (0.31 Imp gal, 0.37 US gal)
(For EUROPE and ZA)
Carburetor:
Type FCR-MX39
Manufacturer KEIHIN
Spark plug:
Type/manufacturer CR8E/NGK
U24ESR-N/DENSO
Gap 0.7 ~ 0.8 mm (0.028 ~ 0.031 in)
Clutch type: Wet, multiple-disc
Transmission:
Primary reduction system Gear
Primary reduction ratio 62/21 (2.952)
Secondary reduction system Chain drive
Secondary reduction ratio 50/14 (3.571)
Transmission type Constant mesh, 5-speed
Operation Left foot operation
Gear ratio: 1st 29/12 (2.416)
2nd 26/15 (1.733)
3rd 21/16 (1.312)
4th 21/20 (1.050)
5th 21/25 (0.840)
Chassis:
Frame type Semi double cradle
Caster angle 27.8˚
Trail 123 mm (4.84 in)

2

2 - 7
SPECMAINTENANCE SPECIFICATIONS (WR426F)
Piston rings:
Top ring
Type Barrel ----
Dimensions (B × T) 1.2 × 3.5 mm (0.05 × 0.14 in) ----
End gap (installed) 0.20 ~ 0.30 mm
(0.008 ~ 0.012 in)0.55 mm
(0.022 in)
Side clearance (installed) 0.030 ~ 0.065 mm
(0.0012 ~ 0.0026 in)0.12 mm
(0.005 in)
2nd ring
Type Taper ----
Dimensions (B × T) 1.00 × 3.35 mm (0.04 × 0.13 in) ----
End gap (installed) 0.35 ~ 0.50 mm
(0.014 ~ 0.020 in)0.85 mm
(0.033 in)
Side clearance 0.020 ~ 0.055 mm
(0.0008 ~ 0.0022 in)0.12 mm
(0.005 in)
Oil ring
Dimensions (B × T) 2.0 × 2.9 mm (0.08 × 0.11 in) ----
End gap (installed) 0.2 ~ 0.5 mm (0.01 ~ 0.02 in) ----
Crankshaft:
Crank width “A”61.95 ~ 62.00 mm
(2.439 ~ 2.441 in)----
Runout limit “C”0.03 mm (0.0012 in) 0.05 mm
(0.002 in)
Big end side clearance “D”0.15 ~ 0.45 mm
(0.0059 ~ 0.0177 in)0.50 mm
(0.02 in)
Small end free play “F”0.4 ~ 1.0 mm (0.02 ~ 0.04 in) 2.0 mm
(0.08 in)
Balancer:
Balancer drive method Gear ----
Decompression device:
Type Manual ----
Cable free play 5 ~ 9 mm (0.20 ~ 0.35 in)
Air filter oil grade: Engine oil ----Item Standard Limit
T
B
B
T
B
T

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SPECMAINTENANCE 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

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SPECGENERAL SPECIFICATIONS (WR400F)
EC211000
GENERAL SPECIFICATIONS (WR400F)
Model name: WR400F (EUROPE)
WR400FP (AUS)
Model code number: 5GSA
Dimensions:
Overall length 2,171 mm (85.5 in)
Overall width 827 mm (32.6 in)
Overall height 1,303 mm (51.3 in)
Seat height 998 mm (39.3 in)
Wheelbase 1,490 mm (58.7 in)
Minimum ground clearance 373 mm (14.7 in)
Basic weight:
With oil and full fuel tank 121.5 kg (268 lb)
Engine:
Engine type Liquid cooled 4-stroke, DOHC
Cylinder arrangement Single cylinder, forward inclined
Displacement 399 cm
3 (14.1 Imp oz, 13.5 US oz)
Bore × stroke 92.0 × 60.1 mm (3.62 × 2.37 in)
Compression ratio 12.5 : 1
Starting system Kick starter
Lubrication system: Dry sump
Oil type or grade:
Engine oil
API “SH” or higher grade
Oil capacity:
Engine oil
Periodic oil change 1.3 L (1.14 Imp qt, 1.37 US qt)
With oil filter replacement 1.4 L (1.23 Imp qt, 1.48 US qt)
Total amount 1.5 L (1.32 Imp qt, 1.59 US qt)
Coolant capacity (including all routes): 1.2 L (1.06 Imp qt, 1.27 US qt)
Air filter: Wet type element
-20
-4-10
140
3010
5020
6830
8640 50
104
122°CTemp.
°F
10W-30
10W-40
20W-40
20W-50
15W-40

2 - 24
SPECMAINTENANCE SPECIFICATIONS (WR400F)
Piston rings:
Top ring
Type Barrel ----
Dimensions (B × T) 1.2 × 3.5 mm (0.05 × 0.14 in) ----
End gap (installed) 0.20 ~ 0.35 mm
(0.008 ~ 0.014 in)0.6 mm
(0.024 in)
Side clearance (installed) 0.030 ~ 0.065 mm
(0.0012 ~ 0.0026 in)0.12 mm
(0.005 in)
2nd ring
Type Taper ----
Dimensions (B × T) 1.00 × 3.35 mm (0.04 × 0.13 in) ----
End gap (installed) 0.40 ~ 0.55 mm
(0.016 ~ 0.022 in)0.9 mm
(0.035 in)
Side clearance 0.020 ~ 0.055 mm
(0.0008 ~ 0.0022 in)0.12 mm
(0.005 in)
Oil ring
Dimensions (B × T) 2.0 × 2.9 mm (0.08 × 0.11 in) ----
End gap (installed) 0.2 ~ 0.5 mm (0.01 ~ 0.02 in) ----
Crankshaft:
Crank width “A”61.95 ~ 62.00 mm
(2.439 ~ 2.441 in)----
Runout limit “C”0.03 mm (0.0012 in) 0.05 mm
(0.002 in)
Big end side clearance “D”0.15 ~ 0.45 mm
(0.0059 ~ 0.0177 in)0.50 mm
(0.02 in)
Small end free play “F”0.4 ~ 1.0 mm (0.02 ~ 0.04 in) 2.0 mm
(0.08 in)
Balancer:
Balancer drive method Gear ----
Decompression device:
Type Manual ----
Cable free play 5 ~ 9 mm (0.20 ~ 0.35 in) ----
Air filter oil grade: Engine oil ----Item Standard Limit
T
B
B
T
B
T

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

2 - 38
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 - 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.