Yamaha YFM25RY Automobile User Manual


 
ENGINE SPECIFICATIONS
2-9
Carburetor
ID mark 4D31 00
Main jet #133.8
Main air jet #140
Jet needle 5DH66-1
Needle jet P-0M (922)
Pilot air jet 1 #85
Pilot air jet 2 #170
Pilot outlet 0.9
Pilot jet #25
Bypass 1 0.8
Bypass 2 0.8
Bypass 3 0.8
Valve seat size 2
Starter jet 1 #55
Starter jet 2 0.5
Throttle valve size #100
Float height 13.0 mm (0.51 in)
Idling condition
Engine idling speed 1500–1600 r/min
CO% 4.0–5.0%
Intake vacuum 34.0 kPa (255 mmHg, 10.0 inHg)
Oil temperature 55.0–65.0 °C (131.0–149.0 °F)
Oil pump
Oil pump type Trochoid
Inner-rotor-to-outer-rotor-tip clearance 0.15 mm (0.0059 in)
Limit 0.23 mm (0.0091 in)
Outer-rotor-to-oil-pump-housing clearance 0.100–0.151 mm (0.0039–0.0059 in)
Limit 0.22 mm (0.0087 in)
Oil-pump-housing-to-inner-and-outer-rotor
clearance 0.04–0.09 mm (0.0016–0.0035 in)
Limit 0.16 mm (0.0063 in)
Oil pressure (hot) 3.0 kPa/1550 r/min (0.03 kgf/cm
2
/1550 r/min,
0.4 psi/1550 r/min)
Pressure check location Cylinder head