Yamaha F6AMH, Service Manual

Page: 288 / 510

CRANKSHAFT, PISTON AND CYLINDER BODY
CHECKING THE CYLINDER BODY
Measure:
Cylinder bore (with a cylinder bore
gauge)
Out of specification
Rebore the
cylinder or replace the cylinder
body.
NOTE:
Measure the cylinder bore in parallel and at
a right angle to the chankshaft. Then
average the measurement.
CHECKING THE PISTON
1. Measure:
Piston diameter (with a micrometer)
Out of specification
Replace the
piston.
Standard Wear limit
Measuring
point “H”
H1: 20 mm (0.8 in)
H2: 40 mm (1.6 in)
H2: 60 mm (2.4 in)
Cylinder bore
“D” 56.000 - 56.015mm
(2.2047 - 2.2053 in)
Taper limit
“T”
––
0.08 mm
(0.0031 in)
Out of round
limit “R”
––
0.05 mm
(0.0020 in)
D = Maximum D1, D2, D3, D4, D5 or D6
T = (Maximum D1 or D2) - (Minimum D5 or
D6)
R = Maximum (D1 or D2) or (D3 or D4) or
(D5 or D6)
Measuring point
“H”
15 mm
(0.59 in)
Standard Piston
diameter “D”
55.950 - 55.965 mm
(2.2028 - 2.2033 in)
Over size piston diameter:
1st: 56.200 - 56.215mm
(2.2126 - 2.2132 in)
2nd: 56.450 - 56.465 mm
(2.2224 - 2.2230 in)
5-54