Husqvarna 543RBX Workshop Manual page 48

• Make sure that the cylinder does not have score
marks.
7.10.4 To examine the piston
• Make sure that the piston ring can move freely in the
groove.
• Examine the surface of the piston for damage and
wear.
• Examine the piston pin.
a) Make sure that the piston pin bearing is not
damaged.
b) Make sure that the piston pin does not have
discolorations.
c) Make sure that the piston pin does not have
damages on the surface against the bearing.
d) If the piston moves too easily, replace the piston
and the piston pin.
e) Make sure that the needle bearing does not
have discolorations or damages.
• Examine the snap rings. If the snap rings have
cracks or discoloration, replace them.
• Measure the piston ring groove (A). Replace the
piston if the groove is larger than 1.3 mm.
48 - Repair instructions
• Measure the piston ring play (B). Replace the piston
ring if the piston ring play is larger than 0.1 mm.
• Put the piston ring in the cylinder and measure the
space with an air gap tool. The space must not be
more than 1 mm.
7.10.5 To assemble the cylinder and piston
1. Carefully put the piston ring on the piston. Make
sure that you do not cause damage to the piston ring
or the piston.
2. Lubricate the needle bearing with 2-stroke oil and
put it into the connecting rod. Make sure that the
needle bearing moves freely in the connecting rod.
B
A
3. Attach the piston to the connecting rod. Point the
arrow at the piston top in the direction of the exhaust
port.
Note: Put a cloth in the crankcase opening to make
sure that the piston rings do not fall into the
crankcase. Make sure that the piston rings are
correctly attached in the grooves.
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