Honda TRX400EX FOURTRAX 1999, Service Manual

Page: 99 / 263

CYLINDER
VALVE SEAT
INSPECTION
Clean all intake and exhaust valves thoroughly t o
remove carbon deposits.
Apply a light coating of Prussian Blue t o each valve
seat.
Tap the valve against the valve seat several times
without rotating the valve, t o check for proper valve
seat contact.
Remove the valve and inspect the valve seat face.
The valve seat contact should be within the specified
width and even all around the circumference.
STANDARD:
1.0
-
1.1
mm
(0.039
in)
SERVICE LIMIT 2.0 (0.08
If the valve seat width i s n o t within specification,
reface the valve seat (page
Inspect the valve seat face for:
Uneven seat width:
Damaged face:
-
Replace the valve and reface the valve seat.
- Replace the valve and reface the valve seat.
UNEVEN SEAT
WIDTH
I
DAMAGED FACE
Contact area (too high low)
- the valve seat.
NOTE:
The valve cannot be ground. I f t h e valve face i s
b u r n e d o r b a d l y w o r n o r if it c o n t a c t s t h e seat
unevenly, the valve
3