does anybody know of any websites that sell parts or give tips to make a 5hp radical or can u spare some advice?

sorry about writing my message twice

Google "making go kart faster".
Dean

After you get a:

Billet flywheel
Billet rod

We can talk about modifications... such as:

Heavier Springs
BP'd valves
Raptor Pistons
Milled, fireslotted, and heads with relieved valve areas
Billet lifters
Cams

I am trying the same on a 6 hp Tech. Power Sport OHV engine. How much more over carbing can a stock rod take? I belive these Power Sport engines are made for modding!;)

what does fireslotting mean

I am trying the same on a 6 hp Tech. Power Sport OHV engine. How much more over carbing can a stock rod take? I belive these Power Sport engines are made for modding!;)

Your not gunna get much performance upgrades for a Tecumseh.

Before you go tearing into the engine have you tried changing the gear ratio of engine to drive wheels ? normally a smaller sprocket on the drive wheel will give you more speed. But dont go crazy with changes like this as it will decrease your take off power and could fry the clutch. So if your running a 10" sprocket on the wheel try a 9" or 8" I think 1" decrease in sprocket size gives you 5 - 10 mph speed increase.

Phillip is right, I have a 3.5hp cart that has no problem keeping up with 6.5's because of a smaller drive gear.