1980 merc 115- operating question

[daryn2]

currious-- is this engine similar to the same aspect of a car engine.......example- battery is needed to start it- but does it run on its own source after that------im trying to track down maybe a wiring problem...

more after this thought...

im wondering if more than just the main positive and negative need to be hooked up to the battery also to run....

im not boat engine smart...


thanks

 

[Chris1956]

Re: 1980 merc 115- operating question

Daryn, I am not sure what kind of cars you drive, however, modern cars need batteries to start and run the fuel injecton. Serious damage will occur if you disconnect a car's battery, while it is running, unless you are running a 1964 Merc Comet, with a generator.

Your motor had a Alternator Driven Ignition. In theory you could disconnect the battery, while the motor runs, and it will continue. However, you will damage your charging system, and the PTT and choke will not work.

 

[j_martin]

Re: 1980 merc 115- operating question

A general overview. There's a couple of coils in the stator. One is used to charge the battery, which is used to operate motors, relays, valves, etc on the motor. The other coil(s) are used to run the ignition system, totally separate from the battery charging system.

I'm curious. How do you propose to track down a wiring problem with a schematic diagram of the system and an understanding of it's operation?

Get a maintenance manual. It's all in the book.

John

 

[daryn2]

Re: 1980 merc 115- operating question

you might not believe it-but the info above you gave to has left me with a better understanding..........

the rear of this boat is a wiring nightmare,,,,previous owner has wires going everywere......i cant imagine how he dealt with it or even how he managed to mess it up so bad...


i just wanted a better understanding of how the marine engine worked...

because so far all i can track down is the main +/- to the engine starter...


seriously.....i want a schematic diagram,,, and a place to start tracing and replacing acordingly....

im not a genious yet---but i have learned a couple things already,, thank you sirs....

 

[j_martin]

Re: 1980 merc 115- operating question

My heart goes out to you. Sounds like a typical bass boat.

The control circuits for the motor all go through the cannon plug and cable system to the throttle box. Sometimes people cut into the heavy cable to put in auxiliary trim and kill switches. Other than that, all the other stuff is secondary stuff wired to the battery, which is charged by the engine through the heavy starter cable.

I like automation, so there's bales of wire in my boat. I set everything up on labeled terminal strips so troubleshooting is possible.

I did get a factory diagram for my boat which in a sophomoric fashion showed every wire in the boat, including the cross wired circuits.

hope it helps
John

 

[turbinedoctor]

Re: 1980 merc 115- operating question

Buy an $80 mercury manual for your motor, tons of good information in there. And like said before, do not disconnect the charging coil wires while running or have them disconnected with it running. You don't need to be replacing a stator just to find out what happens when you do.