Checking/Measuring The Piston - Husqvarna 701 Enduro 2017 Repair Manual

18 ENGINE
177
Using a straightedge and the special tool, check the sealing surface of the cylin­
der head for distortion.
Feeler gauge (59029041100) (S» p. 322)
i
i
Cylinder/cylinder head - sealing area
distortion
< 0.10 mm (< 0.0039 in)
+ *
If the measured value does not meet specifications:
- Change the cylinder.
305589-10
18,4.13 Checking/measuring the piston
Use the special tool to measure play
o
of the piston rings in the piston ring
groove.
Guideline
1
i©—t- ■
©=r~
T
Piston ring - groove clearance < 0.08 mm (< 0.0031 in)
t
Feeler gauge (59029041100) (O p. 322)
» If play
o
is greater than the specified value:
- Change the piston and piston rings.
- Check/measure the cylinder. (SP p. 176)
Check the piston bearing surface for damage.
» If the piston bearing surface is damaged:
- Change the piston and, if necessary, the cylinder.
Check that the piston rings can move easily in the piston ring grooves.
» If the piston ring is stiff:
- Clean the piston ring groove.
305604-10|
• Tip
I
Use an old piston ring to clean the piston ring groove.
311848-10
Check the piston rings for damage.
» If the piston ring is damaged:
- Change the piston ring.
Info
Mount the piston ring with the marking facing upward.
I
Check the piston pin for discoloration or signs of wear.
» If the piston pin has strong discoloration/signs of wear:
- Change the piston pin.
Insert the piston pin into the connecting rod and check the bearing for play.
» If the piston pin bearing has too much play:
- Change the connecting rod and the piston pin.
Measure the piston at the piston skirt, at right angles to the piston pin, at a
distance ©.
Guideline
O
x
Distance ©
31.5 mm (1.24 in)
i
Piston - diameter
Size I 104.955... 104.965 mm (4.13208...
4.13247 in)
©I
e
Size II
104.965... 104.975 mm (4.13247...
4.13287 in)
305603-10
• Info
Piston size O >
s
marked on the piston head.