I have a 88 Suzuki 300 Quadrunner. It runs great and starts easy. recently, after riding for about five minutes, it wants to stall out. If I try to start it immediately, it will hit but not stay running. i can let it sit for a couple minutes and it will start up and stay running but stall out again. What can be causing this? Any known problems? What should I check? Any help at all would be appreciated!