[tkwetzel]

Briggs and Stratton and Tecumseh both make strong engines. For a small engine for a go-kart I would go with one of them over a Honda any day. Honda makes reliable stuff, but I believe that the small engines made by these other companies are just as reliable if not more so. We had a Tecumseh 6 HP engine on our chopper for a long time and it had no problems. It spent a year on a go-kart getting the crap beat out of it before we put it on the chopper too, so it can withstand a beating. We recently sold the 6 HP engine to a friend of mine who is also building a go-kart. He has also started from scratch. Though I do think that you will be very limited with a $500 budget and that to make a decent kart would require about $700 and up (depending on how good you want it).