24
Check valve seat
Measure door line diameter D of valve seat ring, and
its width E.
Standard of door line diameter D
：
Intake
：
28.3
～
28.5
Exhaust
：
24.2
～
24.4
Standard of door line width D
：
Intake valve, exhaust valve 1.0
～
1.2
In case diameter or width of door line of seat ring
is unqualified, repair seat ring until it meets the demand
for correct sealing.
Check valve
Remove valve and check its contact surface
In case coarse, uneven abrasion of contact surface
of valve is found, or contact to valve seat is abnormal,
replacement for valve is needed.
Repair valve seat
Milling cutter of valve seat
Milling cutter with three different angle
Mill upper ring belt area of valve seat by milling cutter of
32°