Yamaha WR450FR Owner's Service Manual page 42

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