Yamaha XF50W Service Manual page 24

Timing chain
Model/number of links
Tensioning system
Valve, valve seats, valve guides
Valve clearance(cold)
Intake
Exhaust
Valve dimensions
y v
r \
Head Diameter
Valve head diameter A
Intake
Exhaust
Valve face width B
Intake
Exhaust
Valve seat width C
Intake
Exhaust
Valve margin thickness D
Intake
Exhaust
Valve stem diameter
Intake
Exhaust
Valve guide inside diameter
Intake
Exhaust
ENGINE SPECIFICATIONS
Item
V
V B
Face Width
Standard
Morse 92RH2005/82
Automatic
0.10~0.16mm
(0.0039~0.0063in)
0.18~0.24mm
(0.0071~0.0094in)
\ . \ . C
T\
Seat Width
15.4~15.6mm
(0.6063~0.6142in)
16.4~16.6mm
(0.6457~0.6535in)
1.48~2.19mm
(0.0583~0.0862in)
1.48~2.19mm
(0.0583~0.0862in)
0.9~1.1mm
(0.0354~0.0433in)
0.9~1.1mm
(0.0354~0.0433in)
0.70mm(0.0276in)
0.70mm(0.0276in)
3.975~3.990mm
(0.1565~0.1571in)
3.975~3.990mm
(0.1565~0.1571in)
4.000~4.012mm
(0.1575~0.1580in)
4.000~4.012mm
(0.1575~0.1580in)
2-5
SPEC 0 *
Limit
...
...
...
...
D
J
Mar gin Thickness
...
...
...
...
1.6mm
(0.0630in)
1.6mm
(0.0630in)
...
...
3.945mm
(0.1553in)
3.930mm
(0.1547in)
4.050mm
(0.1594in)
4.050mm
(0.1594in)