18 ENGINE
18.4.26 Checking the cylinder head
302805-10
302808-10
18.4.27 Installing the valves
302712-11
-
Check valve guides
O
using the special tool.
I
Limit plug gauge (77229026000) (
a
p. 294)
If the special tool is easy to insert in the valve guide:
-
Change the valve guide and valve.
165
-
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) (
ll,JI
p. 291)
Cylinder/cylinder head - distortion of
sealing area
:!> 0.10 mm (:!> 0.0039 in)
If the measured value does not meet specifications:
-
Change the cylinder head.
-
Check sealing seat
fj
of the valves.
Valve - sealing seat width
Intake
Valve - sealing seat width
Exhaust
1.40 mm (0.0551 in)
1 .40 mm (0.0551 in)
If the measured value does not meet specifications:
-
Rework the valve seat.
-
Blow compressed air through all oil channels and check that they are clear.
-
Position valve spring seat
O.
Mount valve stem seal
8.
-
Mount the valve corresponding to its installation position.
-
Mount the valve spring with the tighter coil facing downward.
-
Mount the valve spring retainers.
-
Pre-tension the valve spring using the special tool.
Valve spring mounter (59029019000) (
�
p. 290)
Insert for valve spring lever (77229060000) (
Ill:!
p. 295)