Yanmar BY Series Service Manual page 114

ENGINE
9. Use a wrench (Figure 5-93, (2)) to turn exhaust
camshaft (Figure 5-93, (1)) in direction of arrow
to compress the timing chain tensioner.
Figure 5-93
Figure 5-93
10. While holding the exhaust camshaft rotated,
secure the tensioner in place using special tool
OEM No. 11 3 340 (Figure 5-94).
Figure 5-94
Figure 5-94
5-52
11. Rotate the crankshaft in the normal running
direction until No. 1 cylinder is at TDC of the
power stroke. The front lobe of each camshaft
(Figure 5-95, (1)) will be facing toward the
exhaust side and the timing marks
(Figure 5-95, (2)) will meet.
Figure 5-95
12. Verify position by checking that the camshaft
timing marks (Figure 5-95, (2)) on gears are
aligned. The single mark on intake camshaft
gear must fall between the two marks on the
exhaust camshaft gear.
13. NOTICE: NEVER rotate the crankshaft
backward. If the crankshaft is turned past TDC,
rotate two more turns (720°) to bring No. 1
piston back to TDC. Secure crankshaft in TDC
position with flywheel holding tool
(Figure 5-96).
Figure 5-96
© 2009 Yanmar Marine International
Camshaft and Timing Gear Train
( 2 )
( 1 )
Figure 5-95
Figure 5-96
BY Service Manual
0003771