okay, here it is, can some one tell me if i can put a 350cc, cylinder on a 250cc bottom end, or if that won't work, can i put a whole 350cc, bottem end and all on the frame and hook it to the 250cc's rear end. If you dont get that, i mean can i put a complete 350 on my frame, and make it work.

 

i doubt it, the rod from the smaller bottom end wouldnt accomodate the larger piston. the rod would most likely snap if it could hold a piston that big. and the chances are the cylinder isnt going to fit in the hole anyways. and i read another one of your posts do you realize that the banshee is a two cylinder and i dont know of any 250 twincylindeders that arent V

 

I don't know about the 250 to 350 change but I can tell you it works for the old 125 to 185 Yamaha. Same engine and tranny just a different jug. So I can tell you that some of this stuff was interchangeable.