Checking/Measuring The Piston; Measuring The Piston/Cylinder Mounting; Clearance - Husqvarna FE 350 2015 Repair Manual

ENGINE
18
18.4.15

Checking/measuring the piston

e -• ­
+
18.4.16 Measuring the piston/cylinder mounting clearance
-
Use the special tool to measure clearance
groove.
I Guideline
Piston ring - groove clearance
I
Feeler gauge (59029041100)
t)
If play
-
Change the piston and piston rings.
-
400995-10
Check/measure the cylinder.
-
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.
•
I
305017-10
-
Check the piston rings for damage.
If the piston ring is damaged:
-
Replace the piston ring.
•
I
-
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
C,.
distance
Guideline
0
Distance
Piston - diameter
Size I
Size II
• Info
I
Piston dimensions
-
Check/measure the cylinder.
-
Check/measure the piston.
-
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.
302699-10
I
$ 0.08 mm ($ 0.0031 in)
(� p. 291)
is larger than the specified value:
(� p. 159)
Tip
An old piston ring can be used to clean the piston ring groove.
Info
Mount the piston ring with the marking facing upward.
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)
O
are marked on the piston head.
(I!!',!! p. 159)
(I!!',!! p. 160)
t)
of the piston rings in the piston ring
160