hi Andy, I had checked , and have them under eyes right now: got three mikuni carbs two of the bowl plugs are on the bottom and are diffrent diameter /thread: one is 21,76mm, other one is :15.81mm, so you should convert in imeprial size and see which one is the best ; on my third carb the bowl's plug is on the side , so tell me which one is like yours , send me a PM with your adress and I could send it Monday morning from France.............Pierre