APRILIA TUONO R FACTORY 2007 Service Station Manual page 149

TUONO R_FACTORY
If the width of the valve seat is not within the wear
limits or if the surface is not continuous, the valve
seat can be ground.
Inspect the surface of the valve seat to check
whether:
•
The seat width is not regular: Replace
the valve and grind the valve seat.
•
The surface is damaged: Replace the
valve and grind the valve seat.
Faying surface: too high (C) or too low (D):
•
grind the valve seat.
CAUTION
REPLACE THE VALVE IF ITS SURFACE IS BURNED, SE-
VERELY WORN OR THE CONTACT IS NOT HOMOGENE-
OUS.
Use suitable grinding devices to grind valve seats.
Grinding devices for intake valve seats with angles of:
35° - 45° - 55°
Grinding devices for outlet valve seats with angles of:
35° - 45° - 80°
Engine
ENG - 149