My engine starts OK, idles rough and smokes a lot.<br />Runs fine for 15-20 minutes and simply shut off as if I turned the key off. After a 10-20 minute wait it starts right up. Brought it to the shop. They check out the fuel system, primer bulb and carbs but found nothing. Left the shop and ran the boat home which is about a 20 minute run. No sooner did I get into my slip, the engine shut down. I waited 30 minutes and it started right <br />up. I was told that I might have an ignition problem,loose groung wire or even a bad kill switch. By the way, this problem only started after my 100 hour check up. I know the engine needs to get back to the shop but is there anything I should check first?