Just a thought, anyone know if the cr500 engine fits in the yzf like the crf's. Like the Service Honda bikes. Older family members used to ride in the dunes with the 1986 CR500's. They say they were bullit proof in the sand. They would ride the whole weekend on the same air filter and change the oil once a year. How crazy is that (not recommended). Mind you he also said they worn running shoes, jean cutoff shorts, no T-shirt, and a helmet (at least he was smart enough to wear the helmet. I had two different 86 cr500's, suspension, breaking, and handling were terrible but I don't think anyone has made a motor with as much horsepower before or after.