Maintenance Specifications; Power Unit - Yamaha FT50C Service Manual

SPEC

Maintenance specifications

Power unit

Item
Power unit
Minimum compression
pressure*
Lubrication oil pressure
at 55 °C (131 °F), with
10W-30 engine oil
Cylinder heads
Warpage limit
(lines indicate straightedge
position)
Cylinder head journal inside
diameter
Cylinders
Bore size
Taper limit
Out-of-round limit
Pistons
Piston diameter (D)
Measuring point (H)
Piston-to-cylinder clearance
Oversize piston diameter
1st
2nd
Piston pin boss bore
Piston pins
Outside diameter
Piston rings
Top ring
Dimension B
Dimension T
End gap
Side clearance
* Measuring conditions:
Ambient temperature 20 °C (68 °F), wide open throttle, with plugs disconnected from all cylinders.
The figures are for reference only.
2-3
Specifications
Unit
kPa
(kgf/cm
kPa
(kgf/cm
@ 900 r/min
mm (in)
mm (in)
mm (in)
mm (in)
mm (in)
mm (in)
mm (in)
mm (in)
mm (in)
mm (in)
mm (in)
mm (in)
mm (in)
mm (in)
mm (in)
mm (in)
FT50CEHD
2
, psi)
, psi)
2
37.00–37.02 (1.4567–1.4575)
63.00–63.01 (2.480–2.481)
62.95–62.96 (2.478–2.479)
0.04–0.06 (0.0016–0.0024)
15.974–15.985 (0.6289–0.6293)
15.965–15.970 (0.6285–0.6287)
1.17–1.19 (0.046–0.047)
2.39–2.41 (0.094–0.095)
0.15–0.30 (0.006–0.012)
0.04–0.08 (0.002–0.003)
Model
FT50CED FT50CET
840 (8.4, 122)
100 (1.0, 14)
0.1 (0.004)
0.08 (0.003)
0.08 (0.003)
5 (0.2)
+ 0.25 (0.001)
+ 0.50 (0.002)
2
62Y5A11