My 1996 60 mercury dies in the rpm range of 3000 to 4000. If I'm running along wide open and throttle back it will stall in that range, but run okay at lower/higher RPMs. It runs fine below or above that range. It normally does this after running for a while and when I open the cowling it is wet inside - but not flooded out. The motor is mounted on a 22' pontoon boat. I think it has something to do with the inside getting wet during operation. Any ideas?