17 .4.15 piston, checking/measuring
e-•
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400995-10
311565-10
17 ENGINE
-
Use the special tool to measure clearance
8
of the piston
rings in the piston ring groove.
Guideline
Piston ring - groove clear
ance
� 0.08 mm(� 0.0031 in)
I
Feeler gauge (59029041100) (
�
p. 288)
If clearance
8
larger than the specified value:
-
Change the piston and piston rings.
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Check/measure the cylinder. (
�
p. 192)
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Check the piston bearing surface for damage.
If the piston bearing surface is damaged:
-
Replace the piston and, if necessary, the cylinder.
-
Check that the piston rings move easily in the piston ring
grooves.
If the piston ring is stiff:
-
Clean the piston ring groove.
Tip
An old piston ring can be used to clean the
piston ring groove.
-
Check the piston rings for damage.
If the piston ring is damaged:
-
Change the piston ring.
•
Info
I
Mount the piston ring with the marking facing
upward.
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Check the piston pins for discoloration or signs of wear.
If the piston pin shows severe discoloration/signs of wear:
-
Change the piston pin.
-
Place the piston pin in the connecting rod and check the
seating for play.
If the piston pin seating has excessive play:
-
Change the connecting rod and piston pin.
-
Measure the piston at the piston skirt, at right angles to the
piston pin, at a distance G).
Guideline
Distance G)
5 mm (0.2 in)
Piston - diameter
Size I
77.960 ... 77.970 mm
(3.06929 ... 3.06968 in)
Size II
77.970 ... 77.980 mm
(3.06968 ... 3.07007 in)
193