New piston and cylinder for Siegfried the Simson

Other side of cylinder insert sleeve

No isea where all that metal went. What with this and the state of the piston it is a wonder that Siegfried ran at all.

Simson mice

Look at the base of the liner surround. This is under the carb so mystery oil on fins there can only have come from here.

Knachered piston

Scored piston

Just look at that scoring

Top oil ring gap

All rings v loose with lots of free play up and down. Top oil ring had a 10mm loose piece floating in the groove.

Siegfried - the guilty party at last

As suspected loads of burning on the exhaust side of piston.