1994 polaris slth

I have a 1994 polaris that has been acting up for a long time and no shop can seem to get it fixed. It will start and run great but after you run awhile and let it ilde, it will go dead. When you try and restart it, it just turns over but wont start. If you let it sit awhile, like 5 minutes or so, it will start and run great. Yesterday after running it for about 2 hours, it stopped again and still this morning it will not restart. It is driving me crazy. It only has 113 hours on it and has been doing this for the last 5 or 6 years. HELP???