Repair instructions
7
Remove the seals and the circlip. Carefully pull out
piston and crankshaft. Cover with paper over the
cylinder opening to prevent dirt from coming in.
8
Carefully loosen the circlips D, see fi gures 80 and
81, with a small screwdriver.
9
Press out the gudgeon pin E. Now lift off the piston.
Remove the covers F and the needle bearing G.
Cleaning and checking
Clean all parts, scrape off all gasket residue and
carbon from the following places:
•
The piston crown
•
Top of the cylinder bore (inside)
•
The cylinder exhaust port
•
The base of the cylinder and/or crankcase
See fi gure 82.
Check the following:
•
That the cylinder's surface coating is not worn.
Especially the upper part of the cylinder.
•
That the cylinder does not have any chafe or
cutting marks.
•
That the piston is free from cutting marks.
Minor scratches can be polished off using fi ne
emery paper.
•
That the piston ring is not welded to its track.
•
Remove the piston ring from the piston to mea-
sure the wear. Use the bottom of the piston to
press down the piston ring into the cylinder.
The opening of the ring must not exceed 1
mm. Put the piston ring back into the piston
slot and make sure it is the right way around,
see fi gure 83.
•
That the needle bearing is intact.
•
That the inlet bellows is intact.
•
That air hoses and impulse hose are intact.
50
– English
Fig 79
Fig 80
Fig 81
Fig 82
Fig 83