Timing Chain, Chain Wheels And Chain Tensioner - Westerbeke WPDS-20 Technical Manual

Al3
NOTE: The combustion chamber inserts are a loose fit in the cylinder head. They
must be refitted in their original positions because the cylinder head face is machined
with the inserts installed.
17. Refitting. Reverse the procedure in 1 to 16, noting:
a. The cylinder head gasket is marked to ensure correct fitting.
b. Tighten the cylinder head nuts in the order shown in Fig.
1.
Torque 75 lb. ft.
c. Adjust the valve rocker clearance (see Data).
d. Bleed the fuel system.
TIMING CHAIN, CHAIN WHEELS AND CHAIN TENSIONER
Removing
1. Drain cooling system (refer to Section D) .
2. Disconnect hoses to salt water pump.
Fig. 2
3. Remove four bolts securing salt water pump housing to adapter plate.
4. Remove drive tang between water pump and engine.
5. Remove water pump adapter plate.
6. Slacken alternator mounting and remove belt.
7. Remove alternator.
8. Remove the crankshaft nut, using tool 18G 391.
9. Withdraw the crankshaft pulley, using tools 18G 231 and 18G 231B.
10. Remove alternator mounting bracket and adjustment bracket.
11. Remove the degree plate from the timing cover.
12. Remove the timing cover.
13. Remove the oil thrower from the crankshaft.
14. Retract the chain tensioner slipper as shown in Fig. 2
15. If the chain tensioner alone requires attention, remove it now, but
if
other com-
ponents are to be removed leave the tensioner in position.
16. Remove the camshaft nut using tool 13G 98A.
17. Position the chain wheel marks as shown in Fig.3 then remove the chain ten-
sioner if it requires overhaul.
18. Draw the three chain wheels and chain off their shafts.
19. Refitting. Reverse the procedure in 1 to 18 noting:
a. Check and,
if
necessary, adjust the chain wheel alignment (see Data).
b. Assemble the chain wheels and chain to their shafts with the timing marks as
shown in Fig.
4
c. Release the chain tensioner as shown in Fig.2
d. Ensure that the crankshaft front oil seal is serviceable. If necessary renew the
seal, using tools 18G 134 and 18G 134CR.
e. Centralize the timing cover using tool 18G 3.