I have a sc 400 and when i start it it will run for about 30 mins or so then it just cuts off then if I lert it sit for about 30 mins it will start back up but it won"t run for long. Somebody help me please.

 

Lots of factors can cause this, but 85% of the time, the ecu is to blame for engine control malfunctions, I've seen them hang open injectors, misfires, all sorts of issues. Don't worry you can have it rebuilt if this is the case pretty cheap too. The last one I sent out cost $75

 

Try performing the fuel pump ECU mod, which bypasses the module. Check out the thread somewhere on this site.