18 ENGINE
160
18.4.15 Checking/measuring the piston
e-•
+
400995-10
305017-10
-
Use the special tool to measure clearance
t)
of the piston rings in the piston ring
groove.
Guideline
I
Piston ring - groove clearance
I
$ 0.08 mm ($ 0.0031 in)
I
Feeler gauge (59029041100) (
�
p. 291)
If play
t)
is larger than the specified value:
-
Change the piston and piston rings.
-
Check/measure the cylinder. (
�
p. 159)
-
Check the piston sliding surface for damage.
If the piston sliding 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
I
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:
-
Replace the piston ring.
•
Info
I
Mount the piston ring with the marking facing upward.
-
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
C,.
Guideline
Distance
0
Piston - diameter
Size I
Size II
•
Info
27 mm (1.06 in)
87.965 ... 87.975 mm (3.46318 ...
3.46358 in)
87.976 ... 87.985 mm (3.46362 ...
3.46397 in)
I
Piston dimensions
O
are marked on the piston head.
18.4.16 Measuring the piston/cylinder mounting clearance
302699-10
-
Check/measure the cylinder. (
I!!',!!
p. 159)
-
Check/measure the piston. (
I!!',!!
p. 160)
-
The smallest piston/cylinder mounting clearance equals the smallest cylinder bore
diameter minus the largest piston diameter. The largest piston/cylinder mount
ing clearance equals the largest cylinder bore diameter minus the smallest piston
diameter.
Summary of Contents for FE 350 2015
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