June 25, 201313 yr Author Quick update with thanks to all who helped, especially Dom! I quoted the squish wrong - it was 1.3mm! Disassembled top end and found evidence of blow by on cylinder liner. Ring end gap massive, especially bottom ring which was visibly worn! Cylinder looks in good nick, as does piston. Spoke to factory Kev at GG UK and piston/bore wear within acceptable limits. Sadly piston rings no longer available so had to have a piston kit. Hopefully we will be sorted by the weekend.
June 25, 201313 yr I hope you get it sorted but I have doubts. Ring end gap is constant. your fault is intermittent. often your signs of richness are an ignition fault. see if you can find a garage with a PICOscope or similar and check your HT KVa and wave form, your source coil waveform and your trigger coil wave form. If you identify the source and trigger coil wires and make sure they are accessible these tests will only take a ffew minutes. Some mobile mechanics carry PICOscopes. Cheers
July 1, 201313 yr Do NOT disreguard that seal behind the flywheel. you souldnt have any oil in there for any reason, Although I have squirted WD-40 in there when I got submerged and bike died, helped dry that area out. usually WD40 dries in HEAT though.. If it is weeping you need to get that seal and last I knew this means splitting cases and pulling crank out to replace the seal??? This could cause lean, which can eventually hurt the piston let alone the cylinder, plus hard start. Funny you had such high compression if the rings were so bad????
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