Curiouser and curiouser

I got round to looking at the Norton today after it misbehaving on the way back from Germany, strange thing was I never found any disasters, funnily enough no seizures, no lumps out of valves so Alex and I were running through the possibilities and failed to come up with one. I checked the compression and the right side seemed low, about 90 lbs against 100 on the left (which was also low) , it did feel low on compression on the kickstart also. Alex checked it electronically with an array of electronic wizardry and failed to come to a conclusion so I stripped it (which is the quick way to do it anyway)
The only strange thing was that the carbon on the piston tops was breaking up rapidly so I wonder if the fuels I was using was washing the carbon off and dislodged enough to foul a plug and stick a valve? I'm going to put a new set of rings on, re grind the valves and build it back up and see how it goes, it was starting to use oil so it could do with rings and a hone anyway. Good thing is its not going to cost me a fortune, bad thing is I still can't tell what brought it to a halt. That's life, it was a good excuse to look at the bottom end anyway and say hello to the camshaft! Another day in the garage but hopefully get out for a run tomorrow...
(not on that particular Norton)

Before

During

After!!!!