5-34
Power Unit
4st 2/2.5/3.5 2007
9. Apply thin coat of abrasive compound on the overall valve
seat contact area, and turn valve lapper 1 (commercially
available item) while tapping valve.
10. After ending the work, remove the compound completely
from cylinder head and valve.
11. Check valve seat contact width c.
Perform the work by taking care not to
allow abrasive compound to adhere to
valve stem and valve guide.
Valve Seat Contact Width c : Standard value
1.0 mm (0.04 in)
· Use finer abrasive compound to finish.
· When changing abrasive compound to finer
one, remove present one completely.
· After completion of lapping, wipe off the
compound and then clean.
b Width before correction
c Specified width
MFS2sec05070524.qxd07.5.243:18 PM ページ34