Yamaha F25A - Maintenance Specifications

2-3
SPEC
E
MAINTENANCE SPECIFICATIONS
MAINTENANCE SPECIFICATIONS
ENGINE
Item
Unit
Model
Worldwide F20A F25A
USA, CANADA — F25X
CYLINDER HEAD(S)
Warpage limit mm (in) 0.1 (0.004)
CYLINDER(S)
Bore
Standard mm (in) 65.000 ~ 65.015 (2.5590 ~ 2.5596)
Taper limit mm (in) 0.08 (0.003)
Out-of-round limit mm (in) 0.08 (0.003)
CAMSHAFT(S)
Intake (A) mm (in) 30.884 ~ 30.984 (1.2159 ~ 1.2198)
Intake (B) mm (in) 25.95 ~ 26.05 (1.022 ~ 1.025)
Exhaust (A) mm (in) 30.884 ~ 30.984 (1.2159 ~ 1.2198)
Exhaust (B) mm (in) 25.95 ~ 26.05 (1.022 ~ 1.025)
Camshaft journal diameter mm (in) 36.925 ~ 36.945 (1.4537 ~ 1.4545)
Cylinder head journal diameter mm (in) 37.000 ~ 37.025 (1.4567 ~ 1.4577)
Camshaft runout limit mm (in) 0.1 (0.0039)
Cylinder block inside diameter mm (in) A: Blue 38.032 ~ 38.040 (1.4973 ~ 1.4976)
B: Black 38.024 ~ 38.032 (1.4970 ~ 1.4973)
C: Brown 38.016 ~ 38.024 (1.4967 ~ 1.4973)
ROCKER ARM SHAFT(S)
Outside diameter mm (in) 15.971 ~ 15.991 (0.6288 ~ 0.6296)
ROCKER ARM(S)
Inside diameter mm (in) 16.000 ~ 16.018 (0.6299 ~ 0.6306)
VALVES
Face angle Degree 180, 90, 60
Valve clearance (cold)
Intake mm (in) 0.2 ± 0.05 (0.008 ± 0.002)
Exhaust mm (in) 0.3 ± 0.05 (0.012 ± 0.002)
Head diameter (A)
Intake mm (in) 31.9 ~ 32.1 (1.255 ~ 1.263)
Exhaust mm (in) 25.9 ~ 26.1 (1.020 ~ 1.027)
Face width (B)
Intake mm (in) 2.3 ~ 2.7 (0.091 ~ 0.106)
Exhaust mm (in) 2.5 ~ 2.9 (0.098 ~ 0.114)
Seat width (C) mm (in) 0.9 ~ 1.1 (0.035 ~ 0.043)
A
B