After stripping the engine down and measuring the ring gap, it was bit of a shock to find it so far out of spec..
Standard is 0.4-0.5 mm. I measured mine to find it was 1.75mm
I had come to the conclusion that the engine had been out of this and run in a side car outfit or a race quad as the bike may have done the low miles but the engine had definitely done a fair bit more.
Decided in the end a full strip down was needed to check the bottom end, crank, main bearings etc.
Big list of parts was ordered. Conrod, piston and rings, main bearings 2 inlet valves, cam, full seal kit with water pump seals and valve stem seals, cam chain.
It also had very slight wear to the 6th gear in the drive , so that was also replaced as parts are starting to get a bit sparse for these rfs lumps.
The new genuine piston and rings and the head had been sent of for replanting and was waiting for it to come back...