Getting the jetting right can be an expensive exercise with carburetors. If you get it to a level where it gives the best performance, it should probably need to be changed to suit the weather. I have never raced using petrol as fuel. The major advantage in using methanol is it hides-up the tuning errors. The latent heat of vaporisation of methanol requires the jets to flow about twice as much, so errors are about one-half as significant as when using petrol. Anybody who can get a race bike with carburetors going really fast using petrol, is an excellent tuner. Rich always means slow. I sold my first race bike back to my mate who had built it in the 1950s - I rode it after he had put it back on petrol - it was almost sane, but still went sideways in one corner.
