ENGINE
5-90
6LPA Service Manual
Valve Clearance Inspection and Adjustment
© 2007 Yanmar Marine International
VALVE CLEARANCE
INSPECTION AND
ADJUSTMENT
NOTICE: Check and adjust the valve clearance
when the engine is cooled down.
Valve Clearance Inspection
1. Remove the rocker cover. See step 8 starting in
Cylinder Head Removal on page 5-16.
2. Turn (Figure 5-218, (1)) the crankshaft pulley
clockwise to align its groove to that of the timing
gear cover (Figure 5-218, (2)) and set No. 1
cylinder at TDC of the compression stroke.
Figure 5-218
Figure 5-218
3. Check that the intake and exhaust valve rocker
arm does not move when the crankshaft pulley
is turned in the both directions (about 90°). If
not, turn the crankshaft 360° and position the
mark as shown (Figure 5-218, (2)).
4. Check only the valves indicated by arrows in
Figure 5-219.
• Measure the clearance between the adjusting
screw on the valve rocker arm and valve bridge
using a feeler gauge.
Measuring Valve Clearance at TDC
of No. 1 Cylinder
Figure 5-219
Figure 5-219
• Record the measured valve clearance.
5. Turn the crankshaft pulley 360° and locate the
mark as shown in (Figure 5-218, (2)).
6. Check only the valves indicated by arrow in
Figure 5-220.
• Record the measured valve clearance.
• Measuring Valve Clearance at TDC
of No. 6 Cylinder
Figure 5-220
Figure 5-220
(1)
(2)
0005217
Valve Clearance (Engine Temperature = Cool)
Intake
0.17 to 0.23 mm (0.007 to 0.009 in.)
Exhaust
0.47 to 0.53 mm (0.0185 to 0.0208 in.)
000521
8
0005219