Outdoor Power Equipment (Lawn Mowers, Snow Blowers, Chain Saws and more) Discussions

HI all, We have a gokart we had for a few years for our kids when they were younger! Now they have became teenagers and we would like to modify the motorif possible! I been seaching on the internet, but anymore there is just to much info! LOL!!! Anyway it has a 5 hp b&S engine(model# 136212) wih a Comet Torq-A-Verter! I'm not looking for a complete modify, just a little more get up and go! I heard that changing the governor spring to a 3500rpm spring, that it would increase the speed a little! The proplem is I dont even know where to find that!!!LOL!!!  Any advice on modifing will be appreciated!

P.S. Im not want to rebuild engine, but would be willing to change carb, plug and exhuast, if you can tell me where I find them? Thanks so much, madmax