Yamaha 30D - MAINTENANCE SPECIFICATIONS

2-5
SPEC
E
MAINTENANCE SPECIFICATIONS
MAINTENANCE SPECIFICATIONS
ENGINE
Item Unit
Model(s)
25hp 30hp
CYLINDER HEAD
Warpage limit mm (in) 0.1 (0.004)
CYLINDERS
Bore
Standard mm (in) 59.50 ~ 59.52 (2.3425 ~ 2.3433)
Wear limit mm (in) 59.6 (2.35)
Taper limit mm (in) 0.08 (0.003)
Out-of-round limit mm (in) 0.05 (0.002)
PISTONS
Piston-to-cylinder clearance mm (in) 0.040 ~ 0.045 (0.0016 ~ 0.0018)
Piston diameter (D) mm (in) 59.455 ~ 59.480 (2.3407 ~ 2.3417)
Measuring point (H) mm (in) 10 (0.39)
Pin boss inside diameter mm (in) 15.974 ~ 15.985 (0.6289 ~ 0.6293)
Piston ring groove clearance
(installed)
Top ring mm (in) 0.05 ~ 0.09 (0.002 ~ 0.004)
2nd ring mm (in) 0.05 ~ 0.09 (0.002 ~ 0.004)
Oversize piston diameter
1st mm (in) 59.75 (2.352)
2nd mm (in) 60.00 (2.362)
PISTON PINS
Diameter mm (in) 15.965 ~ 15.970 (0.6285 ~ 0.6287)
PISTON RINGS
Top ring
Type Keystone
Dimensions (B × T) mm (in) 1.9 × 2.4 (0.07 × 0.09)
End gap (installed) mm (in) 0.15 ~ 0.30 (0.006 ~ 0.012)
2nd ring
Type Keystone
Dimensions (B × T) mm (in) 1.9 × 2.4 (0.07 × 0.09)
End gap (installed) mm (in) 0.15 ~ 0.30 (0.006 ~ 0.012)
CONNECTING RODS
Small end inside diameter mm (in) 20.004 ~ 20.007 (0.7876 ~ 0.7878)
CRANKSHAFT
Crankshaft width (A) mm (in) 49.90 ~ 49.95 (1.965 ~ 1.976)
Crankshaft width (B) mm (in) 128.6 ~ 129.0 (5.06 ~ 5.08)
Crankshaft width (C) mm (in) 207.5 ~ 208.1 (8.17 ~ 8.19)
Big end side clearance (E) mm (in) 0.20 ~ 0.70 (0.008 ~ 0.028)
Maximum small end axial play
(F)
mm (in) 2.0 (0.08)