ENGINE
6LPA Service Manual
5-55
Cylinder Block
12/05
© 2007 Yanmar Marine International
3. Completely clean the piston using a brush and
solvent (Figure 5-113).
Note: NEVER use a wire brush.
Figure 5-113
Figure 5-113
4. Measure the piston diameter and oil clearance.
There are three types of pistons having different
piston diameters, which are identified by marks
“1”, “2” and “3”. The marks are stamped on the
piston tops (Figure 5-114, (1)).
Measure the piston diameter at right angle to the
piston pin at the “L” position (Figure 5-114, (3))
from the piston top, using a micrometer.
Figure 5-114
Figure 5-114
1 – SIze Mark
2 – Front Mark (Arrow)
3 – “L” Position
5. Measure the cylinder bore diameter in the
thrust direction. See step 5 starting in Cylinder
Block Inspection on page 5-51.
Figure 5-115
Figure 5-115
1 – No. 1
2 – No. 2
3 – No. 3
4 – No. 4
5 – No. 5
6 – No. 6
7 – Mark 1, 2 or 3
8 – Front Mark (Arrow)
00050
3
6
(2)
(1)
(
3
)
00050
3
7
Piston Diameter
Measurement
position “L“
66.4 mm
(2.6141 in.)
Mark “1”
93.835 to 93.845 mm
(3.6942 to 3.6946 in.)
Mark “2”
93.845 to 93.855 mm
(3.6946 to 3.6950 in.)
Mark “3”
93.855 to 93.865 mm
(3.6950 to 3.6954 in.)
(7)
(7)
(1)
(2)
(
3
)
(6)
(5)
(4)
(
8
)
00050
38