Where can i buy an engine for go-cart?

Kart racing or karting is a variant of open-wheel motor sport with simple, small four-wheeled vehicles called karts, go-karts, or gearbox/shifter karts depending on the design. They are usually raced on scaled-down circuits. Karting is commonly perceived as the stepping stone to the higher and more expensive ranks of motorsports.

The best place to check competitive pricing is ebay on their motor section. Click on links below for some to check out. Otherwise I suggest looking for local small engine dealer near you.