Yamaha F40BWHD - Refacing the Valve Seat; Replacing the Valve Guide

CYLINDER HEAD
5-34
E
POWR
REPLACING THE VALVE GUIDE
Replacement steps
NOTE:
Heat the cylinder head in an oven to 200 °C
(392 °F) to ease guide removal and installa-
tion and to maintain the correct interference
fit.
(1) Remove the valve guide using the valve
guide remover.
(2) Install the valve guide (new) using the
valve guide remover until the circlip
contacts with the cylinder head.
(3) Bore the valve guide using the valve
guide reamer.
REFACING THE VALVE SEAT
NOTE:
After refacing the valve seat or replacing
the valve and valve guide, the valve seat
and valve face should be lapped.
CAUTION:
When turning the cutter, keep an even
downward pressure (4 - 5 kg) to prevent
chatter marks.
Valve guide remover
YM-01122/90890-04016
Valve guide reamer
YM-01196/90890-04016