TOHATSU MFS 8B Service Manual page 135

9. Apply thin coat of abrasive compound on the overall valve
seat contact area, and turn valve lapper (commercially
available item) while lapping valve.
· 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.
10. After ending the work, remove the compound completely
from cylinder head and valve.
11. Check valve seat contact width
Valve Seat Contact Width
1.0 mm (0.04 in)
1. Check rocker arm, rocker arm shaft and rocker arm contact
area for wear. Replace if necessary.
2. Measure rocker arm inner diameter
outer diameter . Calculate oil clearance
Replace if out of specification.
Rocker Arm Inner Diameter
13.01 mm (0.5122 in)
Rocker Arm Shaft Outer Diameter
12.99 mm (0.5114 in)
Oil Clearance Between Rocker Arm Hole and Shaft
0.006 - 0.035 mm (0.00024 - 0.00138 in)
Functional Limit :
Replace if b is over 13.05 mm (0.5138 in).
Replace if c is less than 12.94 mm (0.5094 in).
Replace if b is over 0.060 mm (0.00236 in).
4st 8/9.8 2016
.
: Standard Value
and rocker arm shaft
( = - ).
: Standard Value
: Standard Value
:
Contact width before correction
Specified width
= -
5-31