Re-assembling after Decarbonising

Refit the piston complete with rings and insert the circlip, taking care that this is pushed right home into its groove in the piston boss. The piston is machined to give clearance for the valves and it must be fitted with the larger flat portion to the front, otherwise serious damage will be caused. When refitting the cylinder barrel compress the rings so that they will slide into the bore easily. Avoid trapping them and breaking them, and also see that the ring gaps are equally spaced round the piston, and are not in line.

The utmost cleanliness must be observed when carrying out this opera­tion and the hands should be thoroughly washed after the decarbonising operation, so that no dirt gets on to the piston, which would be likely to abrade it.