Yanmar 6LY3 series Service Manual page 95

Inspecting the Cylinder Block and Components
12/05
Correcting the Valve Seat Angles
Use a seat grinder (Figure 5-18) to correct
unevenness of the seat surface as follows:
Figure 5-18
Figure 5-18
1. Widen the valve seat width (Figure 5-19, (1))
using a 70° grinding wheel.
2. Grind the seat to the standard dimension
(45°) using a grinding wheel with a 15°
chamber.
Seat Angle Ø
Intake Valve
Exhaust Valve
NOTICE: When seat adjustment is necessary,
check the valve and valve guide. If the clearance
exceeds the tolerance, replace the valve or the
valve guide and grind the seat.
6LY3 Service Manual
0005600
45°
45°
© 2007 Yanmar Marine International
Figure 5-19
Figure 5-19
1 – Valve Seat Width
2 – Valve Seat
3. Knead valve compound with oil and finish the
valve seat (Figure 5-19, (2)) with a lapping tool.
NOTICE: Use a rubber cap type lapping tool for
valves without a lapping tool groove slit.
Figure 5-20
Figure 5-20
ENGINE
(1)
(2)
0005601
0005718
5-29