Ace Sports Maxxam 150 2R, Service Manual

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20
VALVE GUIDE
Carbon accumulation o
n
the valve guide will make the
v
alve move roughly, causing the valve to not
open or close properly.
Valve guide abrasion is one of the causes of
white smoke from
the exhaust pipe
.
TO CLEAN CARBON ACCUMULATION OFF THE VALVE GUIDE
• Remove the valve and springs etc.
• Clean the carbon accumulation with a valve guide reamer.
VALVE GUIDE INNER DIAMETER MEASUREMENT
Service Limit
5.03mm
Calculate the clearance between the valve stem and the valve guide
(
t
he inner diameter of the guide subtracted by the outer diameter of the valve stem)
.
Valve Inlet valve Exhaust valve
Service Limit 0.08mm 0.10mm
VALVE GUIDE REPLACEMENT
• Heat the cylinder head to 212 ~ 302°F (100 ~ 150°C)
• Tap the valve guide out with a valve guide remover or similar tool.
Generally, only turn right when using the reamer, and do not
push in or out directly with the reamer.
When the abrasion of the valve guide exceeds the service limit, it should be re-
placed; after replacing a new valve guide, the valve retainer must be adjusted.
The cylinder head must be wholly and quickly heated
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y, or
it will cause the cylinder head to distort. The tempera-
ture is very high, two technicians are recommended.
Do not damage the cylinder joint face