Well I've had my own for about 3 years now, but my uncle used to pull my sister, cousin and I around around in a yard kart that didn't have an engine with his riding lawn mower. So since I was about 8 I'd have to say. Im 21 now. My uncle built serveral karts over the years. Which I was able to drive for fun. I even wrecked one when I was about 11. I hit a parking curb, but good thing I wasn't hurt. I make sure to have fun and keep it safe. Fred

 

i built mine out of a cub cadet mower frame, cut everything off, strechted in 18" bought a seatand wheels , 5hp briggs engine, it was alot of fun, kinda funny when a cop pull along side of you and asks for your DL,, a a a well a a.....

 

Honda Odessy's would be a good thing for you and your son to rebuild. There are quite a few around (here anyway). They are fun, got decent power (250cc or you can go full suspension and get 340cc) and very very safe. We have 10 of them with 6 being fully rebuilt and now just waiting for motors.

 

me and my grandpa built a yard kart out of 1" steel square.we basically measured the length of my legs, added a couple foot for a motor mount. then we added a second frame for bracing, and welded them tog, with maybe 3" peices in between the two. weld on a flat plate for the motor mount. get some cheap bearings and weld em into the back for the axle. my advice however, is dont use one of those $40 centrifugal clutches, theyre good for on road, but when i was younger and only weighed maybe 150, i got stuck in the grass. the best thing for a yard kart are one of those torq-a-verters, with a 3-5hp briggs. its a belt drive with a slipper pulley, and as the RPM's increase, the puley moves to tighten up the belt. they're about 150 bucks, but well worth it. i weigh abt 185 now, and can still do donuts with it, with a 5HP engine. any other questions, just ask. i modify mine all the time to try to make it a little better