Thanks Grumpy for your response.
For something to try, could I? lightly sand the scouring in the bore, put in the best second hand piston and rings I have.
I will make the fuel mix rich, say 20:1 and test run?
With the intention of the rings cleaning the bore up.

I can try this & let you all know how it goes.
Cheers
Mark


Happy is he who penetrates the mystery of things.