Beta Enduro RR 350 2015 Workshop Manual page 116

3
Extraction of valve stem seals from valve stems.
Checking flatness of cylinder head.
B
A
E
114
3.17.4.3 VALVE STEM SEAL AND LOWER STOP
Should there be excessive oil consumption or a
white-like exhaust smoke which cannot be blamed
on the oil-scraper rings on the piston, replace the
valve stem seals 1, intended to prevent excess oil
leakage.
It is recommended to replace them every time the
1
cylinder head is overhauled.
In order to replace them, use needle-nose pliers to
pull them out, being careful not to nick the valve
guide.
Once the valve stem seal is extracted, the lower cup
can be pulled out 2.
2
3.17.5 CYLINDER HEAD: CHECKING
Check the flatness between the head and cylinder
coupling surfaces.
This can be done using a rectified block and a
thickness gauge by positioning the block according
to the directions shown in the figure.
The service limit is:
Check that the state of use of the sliding zones A
with the camshafts and B of the camshaft support
bearing housing are free of scratches or signs of
C
meshing.
Clean the oil passages for lubricating the cylinder
head by blowing compressed air into the holes C,
D and E.
D
WASHER
CYLINDER HEAD BODY
cylinder head flatness service limit: 0.05mm