You got me there. There was a company that shipped karts that was run by a father and son. The son in California and the dad in Illinois. But sure dosen’t look like a web site that would be interested in shipping a kart. Will do a little research into the matter and get back. For now, just have a LOL on me.
LAD Specialties customer / tony kart / rotax / kt100
Try Greyhound. If you have depots near the origin and destination, it can be a decent option. They have size restrictions that might mean you have to pull off wheels, nerfs, etc, and fasten them to the chassis somehow, but I know a lot of folks that have shipped some pretty big things that way, and the prices were reasonable (maybe $100-$200) tops.