free 2 stroke fuel/oil calculator + carb sizer
 

2 stroke fuel/oil ratio calculator
Based on the engine oils viscosity at the higher upper cylinder temps my calculator can recommend the needed fuel/oil ratio. This method agrees basically with the best manufacturers but it can be specific to your engine as RPM and type cylinder cooling affect how much oil is needed. End the guessing game with my free calculator. Read about it and the full scoop on engine oils at All About 2 Stroke Engine Oils and my fuel/oil ratio calculator

Carb diameter calculator
carb diameter = .8 x square root(cc x RPM/1000) was the formula I'm familiar with but once I thoroughly investigated the subject I found the manufacturers size the carb by the desired flow velocity, not by that formula. So I created my own formula to mimic what they have done and it is free to download from 2 Stroke Carburetor Sizing