Decompression Valve; Cleaning, Inspection - Husqvarna 333R Workshop Manual

Cylinder and piston

Decompression valve

Clean the decompression valve and
check that the valve head is not
damaged (burnt) and that the valve
operates easily.
If necessary, grind the valve with fine-
grained valve grinding compound.

Cleaning, inspection

After dismantling, clean the individual components:
1. Scrape carbon deposits from the top of the piston.
2. Scrape carbon deposits from the cylinder's combustion chamber.
3. Scrape carbon deposits from the cylinder's exhaust port.
NOTE!
Scrape carefully with not too sharp a tool so as not to damage the soft
aluminium parts.
4. Wash all the components.
5. Inspect the different components for damage and wear.
Check the piston and cylinder for seizure damage and wear.
Also see the "Analysis and actions" section.
Check the piston ring for wear and damage.
Also see the "Analysis and actions" section.
Check the gudgeon pin.
– If it has blued, it must be replaced.
– If the piston moves too easily both the piston and the gudgeon pin must be replaced.
Check the needle bearing. If it is discoloured or damaged, it must be replaced.
Check the circlips. If they exhibit cracks or are discoloured (caused by overheating),
they must be replaced.
Decompression valve
Clean the decompression valve with
white spirit or thinner and blow dry with
compressed air.
Check that the valve moves easily in
the guide and that the valve head is not
damaged (burnt).
If necessary, grind the valve into the
seat using fine-grained valve grinding
compound.
NOTE!
Clean the decompression valve
properly removing any remaining
valve-grinding paste before it is
assembled.
Fit the decompression valve in the cylinder.
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