Repair Instructions
Cleaning and inspection of the cylinder
Clean all components, scrape off all gasket re-
mains and soot from the following areas:
•
Piston crown
•
Top of the cylinder bore (inside)
•
Cylinder exhaust port
•
Base of the cylinder and/or crankcase
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. See figure 60.
•
That the piston is free of score marks. Minor
scratches can be polished off using fine emery
paper.
•
That the piston ring is not burnt into its groove.
•
Measure the wear on the piston rings. This
must not exceed 1 mm. See figure 61. Use the
piston to push the piston ring downward.
•
That the gudgeon pin bearing is intact.
•
That the intake bellows is intact.
Faults and causes
See Figure 62.
Score marks on the piston (A)
1 Leakage, check not carried out.
2 Too low octane fuel.
3 Too low or incorrect oil in the fuel.
Carbon build-up (B)
1 Too much or incorrect oil in the fuel.
Piston ring breakage
1 Piston ring worn out.
2 Oversized piston ring groove.
50
- English
Fig 60
Fig 61
Fig 62