I have a 2 1/2 HP Tohatsu motor that although it ran and ideled OK, started to miss.. It would run OK but you could hear it kick on and off. After about 15 minutes of running it would quit. No spark was evident. After about 3 hours, you could get spark again and it will run for another 15 minutes and then the same thing happens again. I have disconnected the kill switch to eliminate it from the problem. I am lost and seeking ideas on what is wrong or what I should do. Thank you