ENGINE
5-52
6LPA Service Manual
Cylinder Block
© 2007 Yanmar Marine International
Note: There are three types of cylinders having
different bore diameters, which are
identified by markings of “1”, “2” and “3”
in the upper portion of the cylinder block
(Figure 5-102).
Figure 5-102
Figure 5-102
1 – No. 1
2 – No. 2
3 – No. 3
4 – No. 4
5 – No. 5
6 – No. 6
7 – Mark 1, 2 or 3
5. Measure the cylinder bore diameter at points A,
B and C in the thrust (Figure 5-103, (1)) and
axial directions (Figure 5-103, (2)), using a
cylinder gauge.
Standard bore diameter:
• Mark “1”: 94.000 to 94.010 mm (3.7007 to
3.7011 in.)
• Mark “2”: 94.010 to 94.020 mm (3.7011 to
3.7015 in.)
• Mark “3”: 94.020 to 94.030 mm (3.7015 in. to
3.7019 in.)
Maximum bore diameter:
• 94.23 mm (3.7098 in.)
If the measured bore diameter exceeds the
specified maximum, bore the cylinders or
replace as needed.
Figure 5-103
Figure 5-103
1 – Thrust Direction
2 – Axial Direction
3 – 10 mm (0.393 in.)
4 – Front
6. If the cylinder wear is less than 0.2 mm
(0.008 in.), clean the cylinder ridge with a ridge
reamer (Figure 5-104).
Figure 5-104
Figure 5-104
(
3
)
(6)
(7)
(5)
(4)
(2)
(1)
0005025
(
3
)
(
3
)
0005026
(2)
(1)
(4)
0005027
