I guess I'm confused now. I thought your kit came with a wide 3 piece crank. All of the 4 stroke kits I've seen came with the wide crank as part of the kit. I've seen some kits with 1 piece cranks and some with 3 piece. Do you mean your kit just has the crank arms and not the square shaft spindle part? If so here is a link to a conversion kit that includes that part.
Pyramid 3 pc, Bottom Bracket Conversion Kit | BikepartsUSA
Originally Posted by Nitrohorse
The 4 stokes are a wider engine than the 2 strokes, so the wider crank is necessary. They engine kit contains a three piece "crank set" (two crank arms, and chain sprocket) which requires the "square shaft bottom bracket" to mount the crank set on. Most (practically all) of the bikes I looked at have the one piece cranks on them and that renders the three piece crank set that came with the kit useless. I know my terminology is not the best, and I'm probably not explaining myself in the most accurate way as well.
At any rate, I need the square shaft type bike to bolt my crank set onto.
The Ashtabula type one piece crank will not work for my 4 stroke engine.