Re: 79? Mercury 850 Thunderbolt ignition problem
Welcome to iboats.<br />You state that "it is cutting out". It runs ok until warm, and then, stalls...<br />This could be a coil. Coils do this-- when at normal temps, a coil with an open winding will function perfectly. This is because the broken ends are touching each other. But as the coil heats up and expands, the windings expand to, and the two ends are seperated. It will fail until it cools down again....Can drive ya buggy (I know)..I hate intermittant failures. they tend to make me cuss.<br />It could be a stator or trigger winding for the same reason.(they have coils of wire in them) It could be the cd unit too. You'll need a good volt/ohm meter, and the manual, because it gets into pages of model-specific stuff here.<br /> Check the coils when the engine stalls, (across the winding) You should get between 100-500ohms. Any more, and the winding has break in it, Any less, and the winding is shorting on itself (burnt up).<br />But you're right, they are some of the best-made, best protected coils in the marine industry (IMHO).
