18 ENGINE
18.4.24 Checking the valve spring seat
305014-10
18.4.25 Checking the cam levers
302718-10
18.4.26 Checking the cylinder head
306769-10
305005-10
194
- Check the valve spring seat for breakage and wear (visual
check).
If the valve spring seat is broken or worn:
- Change the valve spring seat.
- Measure the thickness of the valve spring seat.
Valve spring seat - thick
ness
0.90 ... 1 .10 mm (0.0354 ...
0.0433 in)
If the measured value does not meet specifications:
- Change the valve spring seat.
- Check the cam levers and cam lever shafts for damage and
wear.
If there is damage or wear:
- Change the cam levers and/or cam lever shafts.
- Check valve guides
O
using the special tool.
I Limit plug gauge (77229026000) (
�
p. 326)
If the special tool is easy to insert in the valve guide:
- Change the valve guide and valve.
- Check the sealing area of the spark plug thread and the valve
seats from damage and cracking.
If there is damage or cracking:
- Change the cylinder head.
- Using a straightedge and the special tool, check the sealing
area of the cylinder for distortion.
I Feeler gauge (59029041100) (
il,',!i
p. 322)
Cylinder/cylinder head - dis- :c; 0.10 mm (='> 0.0039 in)
tortion of sealing area
If the measured value does not meet specifications:
- Change the cylinder head.