TOHATSU MFS 8B Service Manual page 145

1 Push piston ring into ring gauge 55.000mm (2.1654in)
parallel to top edge.
2. When ring gauge is not available, use piston crown to push
piston ring into to cylinder.
Measure at the top or bottom of cylinder bore
with no wear.
3. Measure piston ring closed gap
specified value.
Piston Ring Closed Gap
Top Ring : 0.15 - 0.30 mm (0.0059 - 0.0118 in)
Second Ring : 0.35 - 0.45 mm (0.0138 - 0.0177 in)
Oil Ring : 0.20 - 0.70 mm (0.0079 - 0.0276 in)
Functional Limit :
Top Ring : 0.50 mm (0.0197 in)
Second Ring : 0.70 mm (0.0276 in)
Replace oil ring when top ring or second ring is
replaced.
1. Measure piston pin outer diameter. Replace piston pin if
outer diameter is less than specified value.
Piston Pin Outer Diameter : Standard Value
14.00 mm (0.5512in)
Functional Limit :
13.97 mm (0.5500 in)
2 Measure piston pin boss inner diameter
clearance between piston pin and pin hole. Replace piston
pin or piston if the clearance is over specified value.
Clearance Between Piston Pin and Pin Boss :
0.002 - 0.012 mm (0.00008 - 0.00047 in)
Functional Limit :
0.040 mm (0.00157 in)
4st 8/9.8 2016
. Replace if it is over
:
, and calculate
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