Port engine breaker cuts off while underway

[georgelbenson]

I know to get a good answer I need to give a lot of detail. Some info maybe be pertinent some not: This past weekend I fired up the port engine and it ran at idle speed fine, went to the fuel dock and filled up. The tank had a little less than 1/8 of a tank of fuel in it. I left the fuel dock and got past the no wake zone and went to 2000 RPMs after a few minutes the port tack went all the way to the right and the engine breaker tripped. Fired it back up and as soon as I got to 2500 RPMs it tripped again. Then the engine would not fire back up. Any ideas, would bad alternator cause this? Thanks for any help you can give. 7.4 1999 Mercruiser engine

 

[Bt Doctur]

Did you look at the voltmeter gauge, ? Do the gauges come alive and does the motor crank over?
Tripping a 50 amp circuit breaker is a serious short or overcharge.It could happen if the battery was accidently disconnected from the engine and the alt spiked.

 

[georgelbenson]

Did you look at the voltmeter gauge, ? Do the gauges come alive and does the motor crank over? Tripping a 50 amp circuit breaker is a serious short or overcharge.It could happen if the battery was accidently disconnected from the engine and the alt spiked.

There is 1 starter battery for both engines. It is connected. I didn't check the volt meter prior to the breaker switching the engine off. Seems like the needle was a little further to the left than the starboard but I am not sure. The engine does not turn over at all now.

 

[Flying Cloud]

There is 1 starter battery for both engines. It is connected. I didn't check the volt meter prior to the breaker switching the engine off. Seems like the needle was a little further to the left than the starboard but I am not sure. The engine does not turn over at all now.

Sorry I'm Late, I was stuck in the Lake Locks
Check the Battery Connections especially Grounds (Battery NEGATIVE) on both Engines, Clean Battery Posts AND sounds like IMHO since you tried a Re-start, this caused the *Anti-Corrosion Grounding (Usually Connected to the Transmission and Stuffing Box) to be Completely Burnt off on the Port Engine.

*So, even though it runs now since ya fixed the Battery connections, ya still gotta remove and replace those Anti-Corrosion grounds, I recommend replacing the entire length of wire. I think they're about a number 6 or 8 wire use same size (Bigger might not be better in this case)!



Still Might not be outta the Woods yet, Check Alternator out put.

Turns Now but, No Start?
Check; ignition control Mod and Electronic Fuel Injection maybe Toast too.

 

[electricaldoctor]

Shifter neutral switch??

 

[Bt Doctur]

Clarify, 1 dedicated starting battery for each engine
With these new systems you need a dedicated battery for each engine . That means nothing else connected to engine systems. There very sensitive to voltage spike and drain downs. Also check to make sure the charging systems are completely separate ,not connected to each other. The house should be on its own,
not connected to the engine system.