Yanmar 4BY2, Руководство по обслуживанию, Страница: 106 / 248

ENGINE
Camshaft and Timing Gear Train
5-44
BY Service Manual
© 2009 Yanmar Marine International
Check and Adjust Camshaft Timing
Check Camshaft Timing
1. Remove cylinder head cover. See Remove and
Install Cylinder Head Cover on page 5-17.
2. 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 5-73, (1)) will be facing the exhaust
side.
Figure 5-73
Figure 5-73
3. Verify position by checking that the camshaft
timing marks on gears are aligned
(Figure 5-73, (2)). The single mark on intake
camshaft gear must fall between the two marks
on the exhaust camshaft gear.
4. Secure crankshaft in TDC position with flywheel
holding tool OEM No. 11 5 180 (Figure 5-74).
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.
Figure 5-74
Figure 5-74
5. Install special tool OEM No. 11 6 321
(Figure 5-75, (1)) on the flats of the intake
camshaft (Figure 5-75, (2)). The tool must set
firmly on the machined gasket surface
(Figure 5-75, (3)) on each side of the cylinder
head. If it does not, the timing must be adjusted.
See Adjust Camshaft Timing on page 5-45.
Figure 5-75
Figure 5-75
Note: Special tool shown on intake camshaft.
Exhaust camshaft is checked in the
same manner but has no adjustment. If
camshaft gears are properly aligned,
exhaust camshaft timing will be correct.
6. Remove special tools.
7. Install cylinder head cover.
Adjust Camshaft Timing
1. Rotate the crankshaft until No. 1 cylinder intake
camshaft lobes are facing down. NOTICE:
NEVER remove the camshaft sprocket bolts.
000 3 771
(2)
(1)
000 3 772
( 3 )
( 3 )
(2)
(1)