Checking The Cylinder Bore; Checking The Piston Clearance; Checking The Piston Rings - Yamaha F200C Service Manual

Piston diameter a:
93.921–93.941 mm
(3.6977–3.6985 in)
Measuring point b:
5 mm (0.2 in) up from the bottom of
the piston skirt

Checking the cylinder bore

1. Measure the cylinder bore (D
measuring points a, b, and c, and in
direction d (D
, D
1 3
to the crankshaft, and direction e (D
D , D ), which is at a right angle to the
4 6
crankshaft.
D
2
D
4
D
6
a 20 mm (0.8 in)
b 60 mm (2.4 in)
c 100 mm (3.9 in)
Cylinder bore (D
94.00–94.02 mm
(3.7008–3.7016 in)
2. Calculate the taper limit. Replace or
rebore the cylinder block if out of specifi-
cation.
Taper limit:
(direction d)
D –D
1 5
(direction e)
D –D
2 6
0.08 mm (0.0032 in)
3. Calculate the out-of-round limit. Replace
or rebore the cylinder block if out of spec-
ification.
Out-of-round limit:
(measuring point a)
D –D
2 1
(measuring point c)
D –D
6 5
0.05 mm (0.0020 in)
69J1D11
–D ) at
1 6
, D ), which is parallel
5
,
2
D
1
D
3
D
5
S69J5B70
–D ):
1 6

Checking the piston clearance

1. Rebore the cylinder or replace the piston
and piston rings as a set, or the cylinder
block, or all parts if out of specification.
Piston clearance:
0.075–0.080 mm
(0.0029–0.0031 in)

Checking the piston rings

1. Check the piston ring dimensions of B
and T. Replace if out of specification.
Piston ring dimensions:
Top ring a:
B: 1.17–1.19 mm
(0.0461–0.0468 in)
T: 2.8–3.0 mm (0.110–0.118 in)
Second ring b:
B: 1.17–1.19 mm
(0.0461–0.0468 in)
T: 3.6–3.8 mm (0.142–0.150 in)
Oil ring c:
B: 2.40–2.47 mm
(0.0945–0.0972 in)
T: 2.3–2.7 mm (0.091–0.106 in)
2. Level the piston ring 1 in the cylinder
with a piston crown.
3. Check the piston ring end gap d at the
specified measuring point. Replace if out
of specification.
Cylinder block
5-48
1
2
3
4
5
6
7
8
9