28
Cylinder head
Valves and valve springs,
replacement (12A-08)
Special tools: 885023
1
Remove the cylinder head, operations 12A-07.
2
Remove the seawater pump, operation 20A-06.
3
Remove the camshaft cover, operations 12A-01.
4
Remove the valve lifters and shims and place each
valve lifter and shim together in a numbered place,
so that they can be returned to their original posi-
tions.
5
Clean the underside of the cylinder head and check
how deep the valve crowns are under the cylinder
head surface, see operation 12A-09.
6
Make a suitable marking on the valve crowns so
that the valves can be installed in their original posi-
tions if they are to be reused.
7
Press the valve springs together with the valve
spring tensioners (A1). Ensure that the spring is
pressed straight downwards so that the valve stem
is not damaged. Remove the valve cotter (B1).
8
Take the load off the valve spring tensioner and re-
move the valve spring washer (B2), valve spring
(B3), valve stem seal (B4) and the spring seat
washer (B5). Remove the exhaust valve (B6) or the
inlet valve (B7).
9
Repeat points 7 and 8 for the other valves.
10
Ensure that the components are clean.
The components in the valve assembly, as shown
in illustration B.
11
Lubricate the valve stems with fresh engine oil and
install the valves B6 / B7 in their respective guides.
Ensure that the valve crown depth, see operation
12A-09.
12
Install the spring seat washers (B5). Install the new
valve stem seals (B4) on the valve guides. Install
the valve springs (B3) and the valve spring washers
(B2).
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