Will, not sure if you plan on racing that kart or if you are just gonna play with it for fun,  but that bent crank is an expensive fix. Just for a decent crank half, new bearings, bottom end seals and labor to press and true the crank you are probably going to spend somewhere around $300-$400. I am guessing your clutch is ruined now too after the chain took out the crankshaft, a new clutch  for a kt runs around $350.  If its an older kart, or you just plan on playing around at a local track, you would probably be money ahead to but a complete running used kt with a clutch from a local shop or off a member here. Basic used engine packages can be bought for usually around $500 or so, and you could sell yours off for parts . Might even be cheaper to pick up another inexpensive kart with a running kt, I see them around here pretty cheap from time to time. Trashing a crank is a tough lesson, they are expensive to fix. I had a clutch come loose on a kt  and tear up the crank badly. I stuck it on the shelf and plan on keeping it for parts in case one of our others has a problem.