Yamaha F200B Service Manual

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7
Checking the piston diameter
1. Measure the piston diameter a at the
specified measuring point b.
Checking the cylinder bore
1. Measure the cylinder bore (D
1
–D
6
) at
measuring points a, b, and c, and in
direction d (D
1
, D
3
, D
5
), which is parallel
to the crankshaft, and direction e (D
2
,
D
4
, D
6
), which is at a right angle to the
crankshaft.
a 20 mm (0.8 in)
b 50 mm (2.0 in)
c 80 mm (3.1 in)
Checking the piston ring
1. Check the piston ring dimensions B and
T.
Checking the piston ring end gap
(reference)
1. Level the piston ring 1 in the cylinder
using a piston crown at the specified
measuring point a.
2. Measure the piston ring end gap b.
Water
temperature
Valve opening a
58–62 °C
(136–144 °F)
Starts opening
above 70 °C
(158 °F)
4.3 mm (0.17 in) or above
Piston diameter a:
93.921–93.941 mm (3.6977–3.6985
in)
Measuring point b:
13.500 mm (0.5315 in) up from the
bottom of the piston skirt
b
a
D 1 D 2
D 3 D 4
D 5 D 6
a
b
c
d
e
Cylinder bore (D
1
–D
6
):
94.000–94.017 mm (3.7008–3.7014
in)
Piston ring dimensions:
Top ring a:
B: 1.200 mm (0.0472 in)
T: 2.800–3.000 mm (0.1102–0.1181 in)
Second ring b:
B: 1.170–1.190 mm (0.0461–0.0469 in)
T: 3.700–3.900 mm (0.1457–0.1535 in)
Oil ring c:
B: 2.400–2.470 mm (0.0945–0.0972 in)
T: 2.300–2.700 mm (0.0906–0.1063 in)
T
B
T
T
B
B
a
b
c
b
a
1
Cylinder block

Yamaha F200B Specifications

General

Brand	Yamaha
Model	F200B
Category	Outboard Motor
Language	English