Faults And Causes; Assembling The Piston And Cylinder - Husqvarna 555 XP Workshop Manual

Faults and causes

Score marks on the piston (A)
1. Leakage, check not carried out.
2. Too low octane fuel.
3. Too low or incorrect oil in the fuel.
Carbon build-up (B)
1. Too much or incorrect oil in the fuel.
See Figure 63.
Piston ring breakage
1. Piston ring worn out.
2. Oversized piston ring groove.

7.22 Assembling the piston and cylinder

1
Oil the gudgeon pin bearing with two-stroke oil and
insert it into the crank rod. See figure 64.
2
Replace the piston with the arrow facing the ex-
haust port, and slide in the gudgeon pin and fit the
circlips. NOTE! Use new circlips. See figure 64.
3
Oil the piston and piston ring with two-stroke oil.
4
Put a new cylinder base gasket in place. Compress
the piston ring and carefully push the piston into
the cylinder opening.
5
Attach the cylinder. The screws must be tightened
crosswise with a tightening torque of 8-10 Nm.
NOTE!
It is very important that the intake system is
sealed. Otherwise the engine may seize up.
A
Fig 63
Fig 64
Fig 65
Repair Instructions
B
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