I'll second that. It will not slip like a clutch needs to. Waste of money.
I don't suggest angle iron for frame members either. Track down some appropriate SHS or RHS. Heck, even Sch40 gas pipe.
You want your kart to be the best? Then a little word of advise from somebody who's been around the block a couple o' times- Stick to tried and true technology. Use a bike, quad, or snowmobile engine. If you do, your biggest problem will be adapting it to fit. No fooling around trying to get a cooling system working right that was never meant to be, no messing around with a driveline that doesn't exist. Adapt the mounts, run the chain, connect the throttle (and clutch/shift if applicable) and go.
Because I promise you, PROMISE... That if you go ahead as planned, you're going to pour an insane amount of time, effort, and money into a pile of scrap that's going to spend a LOT more time down than up. You are probably going to get frustrated and give up, and it'll be a total waste. You may fry the engine in the process, you may not, but I'll say this- the COOLEST kart in the county runs, and runs reliably and flawlessly every time. Nothing cool about being broken down... again.