I love that no matter how many I build, and its most likely in the hundreds by now that I've fully rebuilt each and every single kart is a little different. I really do enjoy the times when I put something together and take it for a test drive around the parking lot and can say, **** I really built something cool this time.
i like pushing my kart or whatever i'm driving to the limits, and fine tuning the steering, gearing, weight distribution,or whatever it may be to get the most out of what i have. and i just like how there is no rules, no one "grading" you on your kart but yourself.
I drove a 12 second daily driver v8 for years and finally got tired of all the mechanic work. I wanted something that was low maintenance, low stress but still a lot of fun.
On a real car you have so many things that can go wrong and it's nice to work on a kart that can be left alone if you run out of time during that day.
Honestly going 30 mph in a kart gets my heart going just as much as 100 mph in a car. These small engines amaze me so much.