Suzuki RM-Z250 Owner's Service Manual page 104

6-14 CYLINDER HEAD, CYLINDER AND PISTON
• Cool down the new valve guides in a freezer for about one
hour and heat the cylinder head to 100 – 150 °C (212 – 302
°F) with a hot plate.
Do not use a burner to heat the valve guide hole to
prevent cylinder head distortion.
• Apply engine oil to the valve guide hole.
Failure to oil the valve guide hole before driving the
new guide into place may result in a damaged guide or
head.
• Drive the valve guide into the hole using the valve guide
installer 1 and attachment 2.
NOTE:
Install the valve guide until the attachment contacts with the cyl-
inder head 3.
# 09916-43211: Valve guide remover/installer 1
09916-44920: Valve guide installer attachment 2
• After installing the valve guides, re-finish their guiding bores
using the reamer.
• Clean and engine oil the guides after reaming.
NOTE:
* Be sure to cool down the cylinder head to ambient air temper-
ature.
* Insert the reamer from the combustion chamber and always
turn the reamer handle clockwise.
# 09916-33210: Valve guide reamer
09916-34542: Reamer handle
VALVE SEAT WIDTH INSPECTION
• Visually check for valve seat width on each valve face.
• If the valve face has worn abnormally, replace the valve.
• Coat the valve seat with Prussian Blue and set the valve in
place. Rotate the valve with light pressure.
• Check that the transferred blue on the valve face is uniform all
around and in center of the valve face.
# 09916-10911: Valve lapper set
CAUTION
CAUTION
15 mm
(0.59 in)