Cheap but powerful option for a go-cart motor?
I'm pretty keen to build a motorized go-cart with my friend, but we both have run out of chores to do for money, too young to get a job and are on a pretty low budget. We've already got a go-cart that doesn't have a motor, but is well-built (welded frame) and has a proper steering mechanism (not just rope attached to the front axle).
Would it be easier to make an entirely new go-cart or to adapt the go cart we've got now to suit the engine we get?
What's a cheap option for a motor that has some torque and can go around 40-50km/h? I'm talking cheap like under $100NZ (around 70$US I think?)
EDIT: PLEASE DON'T SAY BUY A LAWNMOWER ENGINE UNLESS YOU CAN GIVE ME A DETAILED DESCRIPTION OF HOW TO USE A LAWNMOWER ENGINE ON A GO-CART - Lawnmower engines have vertical driveshafts, and you can't just tip them sideways. A V-belt is not ideal.