I have a 1979 Arctic Cat Jag 3000 with the free air 340 in it. It runs fine, but after running about 10-15 minutes (idling or riding it doesn't matter) it will flood out and die. It is a pain to get re-started again. Last year I totally went through the carb, cleaned it, put in a new needle valve, and adjusted everything per specifications.
I'm thinking that maybe I missed something. Other than this problem, the sled runs great. Any ideas?

have you checked the spark when the engine dies? my polaris had a problem similar to yours, i think i narrowed it down to the coil or cdi quitting when it was warmed up. i got a new coil but haven't seen if it solved the problem yet.

Yeah. I was thinking the same thing. All that old electronic stuff gets bad due to the insulation deteriorating over time. If the CDI box was bad, there wouldn't be any spark at all, right? How do you test the coil?

well, it could or it could not. i have heard of cdi boxes sparking when cold but qutting when hot. try packing snow on the cdi or coil when the sled dies to see if that can get it going again. i would try a new coil first because cdis aren't cheap. i don't think there is a way of checking the coil without special tools. just checking the resistance didn't show anything wrong with mine.