Because of their status as not only a recreational vehicle, but a recreational vehicle even for people who already own a recreational vehicle, go-karts enjoy a position as one of the most fun rides to build and drive. You don't need to worry about getting insured if you drive it only on your own property, and you don't need to spend thousands to get it repaired and maintained by certified professionals. Some go-karts are so light you could carry them home if they broke down, and even if you flunked out of auto class in school, you can probably figure out how to build one yourself. That said, there are a couple of points you need to keep in mind regarding homemade go-karts.
It's tempting to just take that old lawnmower apart, grab an abandoned shopping cart, put a folding chair on the thing and call it a day, but the fact is that just throwing a go-kart together is very dangerous. It's not a racecar, no, but it's not uncommon for a homemade kart to reach speeds of 30 or 40 miles per hour, and when you're riding in an unstable rig with no safety features, one loose screw or one poorly welded seam can result in serious injury. There are all sorts of plans on the Web for homemade go-karts, so there's no excuse not to use them.
A good homemade go-kart, even if it has been created from scrap metal you found at the junkyard, has to be built with some degree of professionalism. Be ready to spend a little bit of money to buy or rent certain tools and materials you might need. Safety is key whenever you're dealing with homemade vehicles, whether you're talking about a custom-built jalopy or a simple go-kart. Don't skimp on quality parts and tools, and don't use a welding torch without learning how to do so safely.
The bottom line is that a good homemade go-kart is a safe homemade go-kart. Make sure you're doing everything on the level and don't hurt yourself.