3
115
E
N
G
IN
E ASS
E
M
B
LY AN
D CO
NTRO
LS
3.17.6 CHECKING CAMSHAFTS
Verify the zones
A
and
B
on the camshafts
making sure they have no traces of meshing
or abnormal wear. Make sure the sides of the
teeth
C
are not chipped or have no trace of
abnormal wear.
The zone
A
comes into contact with the cylin-
der head becoming part of a hydrodynamic
support bearing. Zone
B
on the other hand
supports the roller bearing.
Make sure that the shafts in the cam zones
are free of abnormal colouring which is typical
when working without oil.
Use a thickness gauge to check the wear limit
of the cams referring to the values carried in
the table.
Sometimes the cams show small run marks.
This can be accepted, if the finger followers
are without wear and the cam height is inside
the tolerance.
Check on the exhaust camshaft that the spring
1
of the centrifugal decompressor recalls the
rest of the device so that the cylinder segment
D
of the rod
2
protrudes completely without
any play.
Turn the lever
3
all the way to make sure the
device is not jammed.
A
B
C
1
3
D
2
Intake
Exhaust
Displacement
[cm³]
Nominal size
[mm]
Size limit
[mm]
Nominal size
[mm]
Size limit
[mm]
350 - 390
34,1
34,0
33,75
33,65
430
34,1
34,0
33,75
33,65
480
33,75
33,65
33,75
33,65
Cam zone to be checked.
Cam height measurement.
