I have a 1972 Evinrude 125hp Outboard Engine with Electric Shift (no shift cable - 3 pushbuttons on throttle for F/N/R). I've had the engine for about 5 years - it was originally on a 1973 Thompson 18' Trihull runabout, but I moved it to a 1977 Harris 24' pontoon boat, where it still remains. The engine has run well since I got it (I had a head gasket replced 2 years ago, but that is the only semi major repair I've had). At the beginning of the 1992 boating season, the engine died and would not start. I had a mechanic look at it, and he diagnosed a bad electronic control unit and replaced it with an after market unit. The first one did not work at all, the second only allowed the motor to start (it ran fine), bit did not allow it to shut off when the key was turned off (I had to pull the battery wire off or choke it until it stopped). After consulting with Evinrude, he finally got a unit that worked. However, even though the engine runs smoothly, it cuts off abrubtly for no apparent reason. It does this at any RPM level. Sometimes it starts right back up, but usually it will not start - it just cranks over - sounds like it isn't getting any spark. After sitting for an amount of time (sometimes a 1/2 hour or so, sometimes overnight) it will usually restart. Sometimes it doesn't restart at all. My mechanic went through a variety of things - he replaced solenoids, replaced some of the wiring, replaced some parts in the electric shift system (apparently, no new parts are made for this system anymore). We thought it might be overheating, so we replaced the impeller and the thermostat as well as other cooling system parts (not sure what, but I think we replaced just about everything that was replacable in the system). We replaced plug wires and spark plugs. Nothing helped. There is gas getting to the cylinders when it shuts down, but no spark. Does anyone have any ideas?<br /><br />Thanks