Originally posted by roo: G'day fellas, roo from Australia,I read an article in Australasian dirt bike magazine in "98" about a bloke in New Zeland who had set up a "98" WR4 for road racing, It was lowered in every way possible, looked pretty trick and the thing did over 300kph (190mph). I'll try and find the issue and give you more info. Its good to see a bit of experimenting happening. Sorry sir... There is no way on earth that a YZ400 or 426 or WR400 or WR426 will ever do 300kph or 190 mph... And I don't care if you turbocharged it and ran alcohol or nitrous in it. 200kph ?..Yes... I've seen one on a RR track doing 120 mph (or close). And you should know that the Yamaha 400/426's have a bad reliability record when you make them make more power.