Have a 2000 5.7 mercruiser inboard with a 2 barrel carb. Owned the boat for one year with no major problems. Running 30 min at 3500 rpm the eng abruptly went to idle. Looking around I found a stripped post and loose wire on the neg side of the coil. Coil was HOT! I cooled the coil off with ice after putting washers on the post and she started right up. A few miles later same thing; the coil was hot (or at least I'm thinking it is) This happened two more times and finally I called sea tow. I changed the coil and ran the boat 30 min and the same thing happened. Engine will idle and run on the rack at 2000 rpm for 30 min and not shut down. New coil appeared to have heated up on the positive side because the paint was peeling off which could be nothing more than coincidence.
I'm pretty sure it's electrical because until eng or coil cooled it would not crank. Here a few questions for the experts:
1. What would make a coil hot and break down and is that even possible?
2. I replaced the coil with a car coil from car quest with a built in resistor which is required but do I have to use a merc marine coil (maybe higher resistance) or is a coil a coil? Last coil on boat was not merc either.
3. The guy I bought the boat from put a mallory distributor on the engine. It is electronic ignition. Could the cap or the stuff inside the distributor (what used to be points and condenser) make the coil hot? The inside of the cap did have a little corrosion on all 8 contacts.
I'm stretching here. I believe I've eliminated fuel as a problem. Just rebuilt the carb last spring,and no water in tanks. Eng ran perfectly all summer with the stuff it had on it.
Maybe someone out there has had a similar experience. This site has saved me several times.
Thank You. JEC
I'm pretty sure it's electrical because until eng or coil cooled it would not crank. Here a few questions for the experts:
1. What would make a coil hot and break down and is that even possible?
2. I replaced the coil with a car coil from car quest with a built in resistor which is required but do I have to use a merc marine coil (maybe higher resistance) or is a coil a coil? Last coil on boat was not merc either.
3. The guy I bought the boat from put a mallory distributor on the engine. It is electronic ignition. Could the cap or the stuff inside the distributor (what used to be points and condenser) make the coil hot? The inside of the cap did have a little corrosion on all 8 contacts.
I'm stretching here. I believe I've eliminated fuel as a problem. Just rebuilt the carb last spring,and no water in tanks. Eng ran perfectly all summer with the stuff it had on it.
Maybe someone out there has had a similar experience. This site has saved me several times.
Thank You. JEC
