Dismantling - Husqvarna 243RJ Workshop Manual

6
The cylinder and the piston are two of the components exposed to most strain in the engine. They
must withstand, for example, high speeds, large temperature swings and high pressure. Moreover,
they must be resistant to wear. Despite these tough working conditions, major piston and cylinder
failure is relatively uncommon. The reasons for this include new coatings in the cylinder bore,
new types of oil and grease and refi ned manufacturing techniques.
When servicing these components, cleanliness is of the utmost importance. It is therefore
recommended that the cylinder and the area around it be thoroughly cleaned before being
dismantled from the crankcase.
42
Cylinder and piston

Dismantling

Dismantle the following components to make the cylinder accessible:
Air fi lter cover, cylinder cover, carburettor, distance piece, ignition module (do not lose
the insulation sleeves), exhaust muffl er and protective plate.
Remove the 4 screws holding the cylinder against the crankcase.
Carefully remove the cylinder straight up by rocking it backwards and forwards. Make
sure that no dirt enters the crankcase.
502 71 27-02
Remove the circlips from the gudgeon pin.
Dismantle the piston.
505 38 17-05
Use a rag to cover the crankcase opening under the piston.
Use a special tool or a small screwdriver
with a narrow blade and dismantle the
circlips on the gudgeon pin.
Keep your thumb over the circlip to pre-
vent it from fl ying out.
Push the gudgeon pin from the piston
using punch 505 38 17-05.
If the pin is too tight, dismantling is facili-
tated by carefully heating the piston using
a hot air gun.
NOTE!
Do not lose the spacers that are on
each side of the little-end.