Ya, I was looking around on the B&S racing engines. They look pretty
nice. But for now, I'm just looking for a fun play motor to stick in
my mini chopper. I'll probably gear the thing so it won't ever hit
over 35 mph since my butt will only be about 10" off the ground! But
at least I know I will have plenty of power with the 6.5hp engine.
This engine will have no where near the abuse of any type of racing
engine, and most likely less abuse than the average 2 seater go kart
you can pick up at the local sporting good store.

I have learned alot about these 4-stroke engines from the research I
have been doing. I used to run a KT100 in my Emick go kart back in the
80's. Thing would easily to 70mph. But I haven't really been into
this scene since back then. Got into racing 2 stroke dirt bikes.

Anyway, I'll be building myself a go kart after I finish this mini
chopper. I'll have some fun picking out and modifying a nice race
engine.

Thanks again for all the info.