Yamaha F4A Service Manual

E
CRANKCASE, CRANKSHAFT AND CAMSHAFT
POWR
a
10 mm (0.4 in)
Piston-to-cylinder clearance
1. Calculate:
9Piston-to-cylinder clearance
Out of specification ® Replace the
piston and piston rings, the cylinder
or both.
Piston pin inspection
1. Measure:
9Piston pin outside diameter
Out of specification ® Replace the
piston pin.
Piston ring inspection
1. Measure:
9End gap a
Out of specification ® Replace the
piston ring.
NOTE:
Push the piston ring into the cylinder with
the piston crown.
5-31
Oversize piston diameter:
*Over size 1 : 59.25 mm (2.333 in)
Over size 2 : 59.50 mm (2.343 in)
Piston-to-cylinder clearance:
0.035 ~ 0.065 mm
(0.0014 ~ 0.0026 in)
Piston pin outside diameter:
12.995 ~ 13.000 mm
(0.5116 ~ 0.5118 in)
Piston-to-
cylinder
clearance
Cylinder
bore
Piston
diameter
=
-
End gap (installed)
Top ring:
0.10 ~ 0.20 mm
(0.004 ~ 0.008 in)
2nd ring:
0.25 ~ 0.40 mm
(0.010 ~ 0.016 in)
Oil ring:
0.2 ~ 0.7 mm
(0.008 ~ 0.028 in)
*Except for USA

Yamaha F4A Specifications

General

Brand	Yamaha
Model	F4A
Category	Outboard Motor
Language	English