17 ENGINE
17 .4.24 Checking the valve spring seat
305014-10
17.4.25 Checking the cam levers
311631-10
17.4.26 Checking the cylinder head
311637-10
311638-10
-
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
1.40 ... 1.60 mm (0.0551
... 0.063 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) (
l!l;,!
p. 291)
If the special tool is easy to insert in the valve guide:
-
Change the valve guide and valve.
41
41
-
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 (590290411 00) (
a
p. 288)
Cylinder/cylinder head -
distortion of sealing area
:5 0.10 mm (:5 0.0039 in)
If the measured value does not meet specifications:
-
Change the cylinder head.
199