Motorcycles, Snowmobiles, Go-Carts, ATV's and Golf Carts - How do i get everything out of my 12hp

Hey, i have a 12hp Briggs&Stratton I/C and i would like to know how i can get everyone of my horses living fast. I am building a racing lawnmower but i dont want to race with it i just want it to trail ride, mudd bog, and just for fun. i have put a smaller pulley on the transaxle, and plan on puttin a bigger pulley on the engine drive but i dont know where to get one at. Could ne also tell me where i could get one? I would also like to know what i can do to get my engine running at a racing level without taking chances of blowing it up.

for on the safety side, i would just up the rpms a little. otherwise you'd want to start finding racing parts if you want to make it more, but as for the reason as a little bit, the valves will start to float if too much higher.....and of course it will put more strain on the rod, i'd also switch over to a good syn, like mobil 1. i/c briggs. good engine......

If you are serious about running your engine at race levels I would get a billet connecting rod first. As you increase the rpm's and power you will run into various issues (valve float, feeding it enough fuel, timing, exhaust...) but breaking a rod is a very real possibility above about 6'500-7'000 rpm's.

Pilot Dane what would a billet connecting rod do? would it solve all those problems or what?

Does anyone know where i can get a new/used tecumseh 4 speed transaxle? Mine has a hole in the front of it from jamming it in reverse doing 30mph. NOT GOOD