Honda GX270H Manual page 139

62Z7B000.book 8 ページ ２０１２年９月２７日 木曜日 午前１０時２１分
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CYLINDER HEAD/VALVES
VALVE SPRING PERPENDICULARITY
Measure the valve spring perpendicularity.
SERVICE LIMIT:
If the measured perpendicularity is more than the
service limit, replace the valve spring (page 13-4).
PUSH ROD RUNOUT
Check both ends of the push rod for wear.
Check the push rod for straightness.
If necessary, replace the push rod (page 13-4).
VALVE GUIDE REPLACEMENT
Chill the replacement valve guides in the freezer
section of a refrigerator for about an hour.
Use a hot plate or oven to heat the cylinder head evenly
to 150°C (300°F).
To avoid burns, use heavy gloves when handling
the heated cylinder head.
• Do not use a torch to heat the cylinder head;
warpage of the cylinder head may result.
• Do not get the cylinder head hotter than 150°C
(300°F); excessive heat may loosen the valve seat.
Remove the heated cylinder head from the hot plate
and support it with wooden blocks.
13-8
1.5°