Shooting down the modern fuel being the cause ,I had the first model 250 xl [best commuter bike i ever rode] but it was the same trick. It would start every morning at 6 am 1st kick, but on change of shift after one week I had to bump start it the first day. Next time yours won't start just pull out the plug, look at it ,put it back in and my one always started. very mysterious cheers wally.
Just talked to young bloke, with CR250 Wally. That’s exactly what’s happening to the CR250 now. He looks at the plug, puts it back in, and it starts again, but then dies after a while, and has a wet plug, when he removes it. I think we may have a coil, CDI, igniter, stator, kill button, earth or fractured wire problem/irregularity. when he brings it over we might stumble on it straight away with any luck. I wish I had a manual or some other known good parts to try. He said while it is running its heaps better after the carby service. Don’t figure does it
what some people do to bikes, Silastic on a float bowl joint