Yamaha 25BMH, Service Manual

Page: 84 / 446

MAINTENANCE SPECIFICATIONS
SPEC
2-4
E
PISTON RING (2nd)
Type Barrel
(B) mm (in) 2.0 (0.079)
(T) mm (in) 3.0 (0.118)
End gap
(installed) mm (in) 0.20 - 0.35 (0.0079 - 0.0137)
<Limit> mm (in) 0.55 (0.022)
Side clearance mm (in) 0.03 - 0.07 (0.001 - 0.003)
<Limit> mm (in) 0.07 (0.003)
CRANKSHAFT
Crank width (A) mm (in) 56.90 - 56.95 (2.2401 - 2.2421)
(B) mm (in) 153.7 - 154.0 (6.0512 - 6.0630)
(C) mm (in) 39.9 - 40.1 (1.5709 - 1.5787)
Runout limit (D) mm (in) 0.03 (0.0012)
Side clearance (E) mm (in) 0.2 - 0.7 (0.0079 - 0.0276)
Maximum axial play (F) mm (in) 2.0 (0.079)
CONNECTING ROD
Small end diameter mm (in) 23.904 - 23.917 (0.941 - 0.942)
CARBURETOR
Main jet (M.J.) # 130
Main air jet (M.A.J.)
φ
mm (in) 2.0 (0.079) 1.0 (0.039)
Main nozzle (M.N.)
φ
mm (in) 4.0 (0.157)
Pilot jet (P.J.) # 68
Pilot air jet (P.A.J.) mm (in) 0.8 (0.031)
Pilot screw (P.S.) turns out 1 - 1/4 ± 3/4
Valve seat size (V.S.) mm (in) 1.2 (0.047)
Float height mm (in) 14.5 (0.571)
Idling speed r/min 1,100 ± 50
Item Unit
Model
Worldwide 25BMH 30HMH