well hey pghruby is the 05' carter a howhit??? I know from just the looks of it, from what ive seen, it looks like it but that dont mean nothing i know

Only Yerf-Dog, Tomberlin and Baja used the Howhit engine. I'm not sure of of the make of your Carter 150 engine, but you need the 57.4mm rings.

thanx!

The 57mm rings will work with Carter, Kinroad, and Twister 150cc karts.

Are they close enough that it does not matter whether you use the 57mm or 57.4mm rings? It seems that there would be 1.25mm larger gap if you used the smaller rings.

It does matter. Apparently Kinroad, Carter, and Twister 150cc engines all use the same 57.4mm rings. I can order rings from any of these companies and they will interchange with any of the above engines and will end-gap at .005-.006".

However if I try and use these rings on Yerf or Howhit engines, they will not fit, or if they do fit, they are too tight with NO end gap. You can make the 57.4mm rings fit on some of the Howhit engines (if the piston ring grooves are the same width), but you'll have to do some filing to get the correct end gap. So I assume that Yerf/Howhit 57mm rings would be too small (and in some cases to thick) to work on Twister/Carter/Kinroad cylinders.

So Ric, I'm confused from what you posted earlier. I think you meant to say 57.4mm rings with Carter Kinroad and Twister.