Camshaft Inspection; Valve Guide Replacement - Yamaha F15A Service Manual

POWR
a
b
a
CAMSHAFT AND VALVES
b

Camshaft inspection

1. Measure:
9 Camshaft lobe dimensions a and b
Out of specification → Replace the
camshaft.
Camshaft lobe diameter:
a IN: 23.895 ~ 23.995 mm
b IN: 19.950 ~ 20.050 mm
a EX: 23.917 ~ 24.017 mm
b EX: 19.950 ~ 20.050 mm

Valve guide replacement

Replacement steps:
NOTE:
Heat the cylinder in an oven to 200 °C
(392 °F) to ease valve guide removal
and installation and to maintain the cor-
rect interference fit.
8 Remove the valve guide with the
valve guide remover.
Valve guide remover:
YM-01122/90890-06801
8 Install the circlip and the new valve
guide with the valve guide installer
and valve guide remover.
Valve guide installer:
YB-6308/90890-06802
8 After installing the valve guide, bore
the valve guide with the valve guide
reamer to obtain the proper valve-
stem-to-valve-guide clearance.
Valve guide reamer:
YM-01196/90890-06804
cC
8 When installing and removing the
valve guide reamer, apply machining
oil and turn the reamer clockwise.
8 Reface the valve seat when replacing
the valve guide.
5-27
(0.9407 ~ 0.9447 in)
(0.7854 ~ 0.7894 in)
(0.9416 ~ 0.9456 in)
(0.7854 ~ 0.7894 in)
E