I just bought a 99 YZ400. I will never again buy another two stroke!! My question is this: Does anybody use race fuel instead of premium pump gas in their 400/426?? How high of octane fuel can I use without big jetting changes and/or engine modifications? On my old two strokes I used to use a 98 octane race fuel. Fairly cheap but very clean burning (none of those additives that you get at the pump). Is there any benifits to useing a higher grade fuel in this bike or am I wasting my money buying race fuel??