I have a 1986 Bayliner Capri 2.3 Volvo (AQ131/Penta 270). Boat starts fine and runs great for about 10 minutes then engine stumbles and shuts down. Will crank over fine but won?t start until it has cooled down. Ignition coil is too hot to touch. No spark when coil gets hot. Coil sits on back of engine, on top near exhaust manifold. I have replaced all tune up parts including the coil (still gets too hot), new alternator and any old wiring that looked suspect. Engine temp is fine. I do remember forgetiing to reconnect the cold water inlet hose in the spring after storage and I ran the boat for a bit until I noticed. The problem started right after that. I replaced the cold water impeller right after that mistake with the hose. Warm water does come out of the lower unit so the cold water system seems to be working. Please help with suggestions on what to check (i.e. exhaust manifold, etc.) I am lost. Thanks.