Yamaha F400A 2022 - Page 364

7-64
Cylinder head
1. Reface:
• Valve seat
a. Reface the valve seat using the special
service tools.
b. Cut the surface of the valve seat using
a 45° cutter by turning the cutter clock-
wise until the valve seat face has be-
come smooth.
Do not overcut the valve seat. To prevent
chatter marks, make sure to turn the cutter
evenly using a downward force of 40–50 N
(4.0–5.0 kgf, 8.8–11.0 lbf).
c. Adjust the top edge of the valve seat
contact width using a 30° cutter.
A. Worldwide
B. USA and Canada
Valve seat cutter holder
90890-06316
Intake:
Valve seat cutter 30–38
90890-06817
Valve seat cutter 45–38
90890-06816
Valve seat cutter 60°
90890-06324
Exhaust:
Valve seat cutter 30°
90890-06326
Valve seat cutter 45°
90890-06325
Valve seat cutter 60°
90890-06323
Neway valve seat kit
YB-91044
604530
A
45
45
30
30
60
B
A. Worldwide
B. USA and Canada
a. Slag or rough surface
A
B
a
45°