I purchased a boat with a 1973 115 horse Evinrude v-4, model 115393m, serial jo7839. Previous owner said he thought there was an electicical problem. When I purchased it the wiring harness was unplugged and also battery cables. I hooked everything back up, put in a battery and turned the key. The engine turns over, but i'm pretty sure no fire coming out of the 4 coils. Previous owner said there was a fuse box under the helm. Would I begin there or is there some sort of electronic ignition? The wiring for the coils go to a junction box at the rear of the engine, then lead under the "flywheel". I understand cars, but not boat engines.
You can get a pretty good idea of what parts are in that engine from the online factory parts list: epc.brp.com. Also, you can get some online ignition help from cdi.com. Both sites have a lot of really helpful information. If you really want to get into doing it yourself, you should get an original factory service manual from the original publisher: outboardbooks.com. Don't settle for any other service manual.