Yanmar 6LY3 series - Page 105

ENGINE
Inspecting the Cylinder Block and Components
12/05
6LY3 Service Manual
5-39
© 2007 Yanmar Marine International
Figure 5-43
Figure 5-43
Measuring Piston Ring Gap
• Push the piston ring (Figure 5-44, (3)) into a
cylinder bore approximately 30 mm (1.2 in.)
(Figure 5-44, (4)) from the bottom of the cylinder.
• Measure the piston ring gap (Figure 5-44, (5))
with a feeler gauge.
Figure 5-4 4
Figure 5-44
1 – Head Surface
2 – Cylinder Block
3 – Piston Ring
4 – Approximately 30 mm (1.2 in.)
5 – Piston Ring Gap
Replacing the Piston Rings
• Thoroughly clean the ring grooves when
replacing piston rings (Figure 5-44, (3)).
• The side with the manufacturer's mark
(Figure 5-45, (1)) must face up.
Figure 5-4 5
Figure 5-45
Piston Rings
Standard Limit
Top Ring
Groove
Width
2.626-2.646 mm
(0.1033-0.1041 in.)
2.746 mm
(0.1081 in.)
Ring Width
2.470-2.490 mm
(0.0972-0.0980 in.)
2.450 mm
(0.0964 in.)
Clearance — —
Second
Ring
Groove
Width
2.570-2.585 mm
(0.1011-0.1017 in.)
2.140 mm
(0.0842 in.)
Ring Width
2.470-2.490 mm
(0.0972-0.0980 in.)
1.950 mm
(0.0767 in.)
Clearance
0.080-0.115 mm
(0.0031-0.0045 in.)
0.200 mm
(0.0078 in.)
Oil Ring
Groove
Width
4.010-4.025 mm
(0.1578-0.1582 in.)
4.130 mm
(0.1625 in.)
Ring Width
3.970-3.990 mm
(0.1562-0.1570 in.)
3.950 mm
(0.1555 in.)
Clearance
0.020-0.055 mm
(0.0007-0.0021 in.)
0.150 mm
(0.0059 in.)
0005626
Piston Ring Gap
Standard Limit
Top Ring Gap
0.30-0.50 mm
(0.0118-0.0196 in.)
1.5 mm
(0.059 in.)
Second Ring Gap
0.50-0.70 mm
(0.0196-0.0275 in.)
1.5 mm
(0.059 in.)
Oil Ring Gap
0.25-0.45 mm
(0.0098-0.0177 in.)
1.5 mm
(0.059 in.)
0005627
(1)
(2)
(3)
(4)
(5)
0005628
(1)