Wasatchmtnbike

Thanks! I think I'll try a 3 1/2" pulley.

Ok, I'm new to this forum and I have a problem I need help with. Please keep in mind that I'm not very experienced in Physics, so I thought I would ask the experts. A while back I bought a used chipper-shredder with a Tecumseh 8HP gas engine that was bad, it broke a piston and had a hole in the side of the engine. Anyhow, on the original 8hp engine it had a side shaft that turned a 4"diameter pulley. I have replaced the 8hp engine with a 6.5hp engine. I'm hoping to try to put a pulley wheel on the new 6.5 hp engine that will get me close to the same power that the 8hp engine had. Do I go with a larger diameter pulley wheel or a smaller diameter pulley wheel? My brother says a smaller diameter pulley wheel, he said it would turn a little slower but should be close to the same power. I think that I would agree with my brother but I'm not sure how much smaller that pulley needs to be. I hope I have given all the info you need to help me with this. If I am on the wrong form please tell me. Anyhow, I thought I would give it a try. Thanks guys, Gary