I had a bike in a few years ago that was a 500 motor in the 250 frame.
It was suspected of being Martys bike but I beleive they built a few of them in the day.
I think it belonged to a forum member but can't remember now.
From memeory I repaired the pipe on it as it had a custom fitted pipe.
That was my bike Geoff. Thanks, the welding job you did on the pipe has stood up well. The conversion job done on the frame was pretty neat, that's why I thought it may have been Marty's bike, but in fact must have been a copy. I've no idea who built these bikes.
I removed the radiator shrouds and fitted an RM465 tank, which I think looked a little better.
Cheers
Jady