I have the original spark plug set to 0.025" and a spare set to 0.060" and it sparks ok, but not blue. I haven't done, the large gap on the original, so I'll try that.
I have never taken the muffler off, so that might be a possibility.
I'll also see if I can find a spark l=lug tested in a garage, they test them while pressurized.
I got the price of a new piston and rings, 50uk pounds, too much to justify, so let's hope the muffler is blocked.
Cheers, Camerart.
