The “stoichiometric” (chemically correct) air to fuel ratio of methanol is about 6.46-1. 5-1 A/F ratio, which produces maximum power, is 29% richer than chemically correct.
Methanol requires about 250% as much fuel as gasoline for best (richer) full-throttle power,, so the diameters of the passages will have to be enlarged as much as 58% (flow varies roughly as the square of the diameter - 1.58 squared = 2.50, &c.).
The main jet should be enlarged based on the same
250% proportion, so the jet diameter will have to be enlarged as much as 58% as well.
These increases are in addition to any enlargement made for tuning purposes, and are not added (summed) but are incremental.
