Cylinder and piston
Remove the gudgeon pin circlips.
Dismantle the piston.
505 38 17-05
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 off soot deposits using a not too sharp tool so as not to
damage the soft aluminium parts.
4. Wash all the components.
5. Inspect the diff erent 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 possible breakage.
Also see the "Analysis and measures" 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.
Remove the gudgeon pin circlips.
Use small fl at nose pliers and remove the
gudgeon pin circlips.
TIP!
Keep your thumb over the circlip to pre-
vent it from fl ying out.
Press out the gudgeon pin from the piston
using the punch 505 38 17-05.
If the pin is too tight, carefully warm the
piston.
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