Originally Posted by
oldguy829
5HP is common. 8 is enough to pull you nicely, If you don't make the kart weigh a ton.
Look into a "Torque-a-verter" Northern used to carry them. It's a double pulley and belt system. At engine idle there is no pull, as RPM increases the pulleys come together. Faster you go, the more the pulleys swap sizes. Generally 3.5 to 1 to start and better than 1-1 high end. Basically a variable speed automatic transmission. Eliminates the need for a clutch.
We have built several. Find the locat Kart club and ask around. Racing karts become obsolete. We have gottem them for free. Lots of good steering parts, hydraulic disc brakes, carrier bearings, etc.
Here's my sons last creation. 8 HP, Torque A Verter, hydraulic disc brakes, Scary fast.
don't remember the frame on mine, been too long, but I do remember the twin homelite chainsaw engines.. we had centrifugal force clutches. as the RPM increased the central part expanded to clamp against the outer shell which had the drive chain gear on it..
I do remember the wicked fast tho..
Sam