Inspection Of Rocker Arm And Rocker Arm Shaft - TOHATSU MFS25 Service Manual

9. Apply thin coat of abrasive compound on the overall valve
seat contact area, and turn valve lapper (commercially
available item) while tapping valve.
Perform the work by taking care not to
allow abrasive compound to adhere to
valve stem and valve guide.
• 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.
Check valve seat contact width c.
11.
Valve Seat Contact Width c : Standard Value
1.0 mm ( 0.04 in )
14) Inspection of Rocker Arm and
Rocker Arm Shaft
1. Check rocker arm, rocker arm shaft and rocker arm contact
area a for wear. Replace if necessary.
Measure rocker arm inner diameter b and rocker arm shaft
2.
outer diameter c. Obtain oil clearance d ( d = b – c).
Replace if the clearance is out of specified range.
Rocker Arm Inner Diameter b : Standard Value
13.01 mm ( 0.5122 in )
Rocker Arm Shaft Outer Diameter c : Standard Value
12.99 mm ( 0.5114 in )
Oil Clearance Between Rocker Arm Hole and Shaft d :
0.006 to 0.035 mm ( 0.00024 to 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 d is over 0.060 mm ( 0.00236 in ).
25/30 2006
CAUTION
a
c
b
d = b – c
b
c
5
45˚
5-37