Go-karts are short, light cart frames designed to be driven by small three to five horsepower engines. They are machines that can be built or upgraded for next to no investment. One such upgrade is a new engine. Engines specifically designed for go-karts can be purchased, however, lawnmower engines are perfect for swapping onto go-kart frames. They are small, easy to come by, and significantly faster than the current go-kart engines. This article explains how to mount a lawnmower engine onto a go-kart in a few simple steps.
Buy or find the lawnmower (push mowers work best) that you will be getting the donor engine from. Check the engine for major damage and see if it will start up. Check to make sure the pull cord is not jammed (this is a common problem).
Disconnect the blade from the driveshaft on the bottom of the mower deck. This can usually be done by loosening the one or two screws located on the blade.
Loosen the bolts holding the engine to the mower deck and break the engine free from the deck. Detach any wires or cords connecting the engine to the deck or the handlebar.
Fashion a bracket from the stainless steel sheet metal that mounts the engine on its side at a 90-degree angle. This allows the driveshaft to be located in the proper position to attach the cogs and chain.
Mount the cog to the driveshaft and connect the chain to the go-kart's axle cog. Attach the gas tube to the carburettor and connect all of the electrical connections as they were on the lawnmower. Pull the cord and get started racing.
Purchase an engine with a horizontal driveshaft so you will not have to mount it on its side. Check junkyards and small engine repair shops to find old engines for sale.
Make sure the engine you use is not the open-cell kind that will allow oil to spill into the carburettor if tipped on its side. This could prove very detrimental if used for a go-kart application.