Repair Instructions
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 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 ring. This must not exceed 1 mm. See figure 62. Use the pis- ton to push the piston ring downward.
• That the gudgeon pin bearing is intact.
• That the intake bellows is intact.
• Pressure test the decompression valve. Carry out pressure testing on the decompression valve as follows. See also figure 68.
A. Fit the pressure gauge tool 531 03
B. Pump up the pressure to 80 kPa (0.8 bar). C. Wait 30 seconds.
D. The pressure must not fall below 60 kPa (0.6 bar).
Unscrew the cover plates for the carburettor and muffler. Tighten the screws to the stated torque. Remove the pressure test connection 503 84
Fig 62
Fig 68