6 | Cylinder and piston |
| Inlet manifold |
| Remove the air filter and carburettor. |
| Remove the inlet manifold (A) from the |
| partition (B). Check that it does not |
| exhibit cracks or other damage that can |
| cause leaks between the carburettor |
| and cylinder. If necessary, fit a new inlet |
| manifold in the reverse order as set out |
| for dismantling. |
| NOTE! |
| Exercise caution if the inlet |
| manifold is fitted using a |
| screwdriver so as not to make any |
| holes in the rubber wall. |
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.
Assembly
Lubricate the gudgeon pin’s needle bearing with a few drops of engine oil and fit the piston.
Assembly
Lubricate the gudgeon pin’s needle bearing with a few drops of engine oil. Direct the arrow on the top of the piston towards the exhaust port.
Press in the gudgeon pin and fit the circlips.
NOTE!
Place a rag in the crankcase opening to prevent the circlip from falling into the crankcase in case it should fly out.
Check that the circlips are correctly fitted into the grooves by turning the clips with
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