Yamaha F50D Servise Manual - page 30
Specification
1-9
SPEC
Power unit technical data
Power unit
Cylinder head assembly
Item
Unit
Model
F50DET
FT50CET
FT50CED
FT50CEHD
Cylinder
Minimum compression pres-
sure (*1)
kPa
(kgf/cm
2
, psi)
840.0 (8.4, 121.8)
Engine oil
Oil pressure (*2)
at 60 °C (140 °F) with SL
10W-30 engine oil and at
900 r/min
kPa
(kgf/cm
2
, psi)
160.0 (1.6, 23.2)
Item
Unit
Model
F50DET
FT50CET
FT50CED
FT50CEHD
Cylinder head
Warpage limit
mm (in)
0.10 (0.0039)
Valve stem
Diameter
Intake
mm (in)
5.475–5.490 (0.2156–0.2161)
Exhaust
mm (in)
5.460–5.475 (0.2150–0.2156)
Runout
Intake
mm (in)
0.030 (0.0012)
Exhaust
mm (in)
0.030 (0.0012)
Valve stem guide
Inside diameter
Intake
mm (in)
5.500–5.512 (0.2165–0.2170)
Exhaust
mm (in)
5.500–5.512 (0.2165–0.2170)
Stem-to-guide clearance
Intake
mm (in)
0.010–0.037 (0.0004–0.0015)
Exhaust
mm (in)
0.025–0.052 (0.0010–0.0020)
Valve spring
Free length
mm (in)
39.85 (1.569)
Tilt
mm (in)
1.7 (0.07)
(*1) Measuring conditions:
Ambient temperature 20 °C (68 °F), wide open throttle, with spark plugs removed from all cylin-
ders. The figures are for reference only.
(*2) For details of the checking method, see “Checking the oil pressure” (7-1). The figures are for ref-
erence only.