Honda NSA700A DN-1 2009, Service Manual

Page: 252 / 654

CYLINDER HEAD/VALVE
VALVE SEAT INSPECTION/REFACING
INSPECTION
C lean all intake a n d e x h a u s t v a lv e s th o ro u g h ly to
re m o v e carbon d eposits.
A p p ly a th in coat o f P russian B lue to each v a lv e
face.
T a p th e valve a g a in s t th e v a lv e seat several tim e s
u sing a h a n d -la p p in g to o l, w ith o u t ro ta tin g v a lv e , to
m a k e a clear p attern .
R e m o v e the v a lv e and inspect th e v a lv e seat face.
NOTE:
• T h e v a lv e c a n n o t be g ro u n d . If th e v a lv e fa c e is
burned o r b a d ly w o rn o r if it contacts th e seat
u n e v e n ly , rep lace th e v a lv e .
Inspect th e v a lv e seat face for:
• U n e v e n s e a t w id th :
- Replace th e v a lv e and reface th e v a lv e seat.
• D a m a g e d face:
- Replace th e v a lv e an d reface th e v a lv e seat.
W ID T H
• C ontact are a (too high o r to o lo w area):
- Reface th e v a lv e seat.
T O O L O W T O O H IG H
In sp ect th e w id th o f th e v a lv e seat.
T h e valve s e a t c o n ta c t s h ou ld be w ith in th e s p eci­
fie d w id th and even all a ro u n d th e c irc u m fe re n c e .
STANDARD: 0.90 - 1.10 mm (0.035 - 0.043 in)
SERVICE LIMIT: 1.5 mm (0.06 in)
If th e valve seat w id th is n o t w ith in sp ecification ,
rcfacc th e v a lv e scat.
H A N D -L A P P IN G TO O L
9-20