Joe,<br /> I have a starting problem (self-induced I fear) with my 1978-10EL78 engine (It won't). Approx 1 year ago I crossed the leads to my battery then quickly removed them (about 20 seconds went by) after I observed smoke raising from the engine front. I then connected the battery correctly, the engine ran fine and I soon forgot about it. Approx 1 month ago the engine started to run erratic and sometimes died only when I turned the boat/engine at far left and right angles. A friend of mine unplugged the kill wire (black with yellow stripe) under the motor cover and the erratic/die problem went away. He suspected I had a bare area in this wire and when I turned the steering wheel to extreme angles the bare area touched the engine housing which killed the engine. I installed a plastic wiring loom around the wires exiting the motor compartment and secured it with zip ties and that problem went away. About 2 weeks later I started the motor and was warming it up when, while idling unattended, the engine suddenly quit as if someone turned the ignition key to off (which didn't happen). When I attempted to start it back up, it turned over fine but would not start...as if it had no spark. I think it is not a fuel problem as the fuel pump is about 1 year old and the discharge line pump out fuel when the engine is turned over. <br /> I commenced trouble shooting a couple of days later (with a fresh battery...hooked up properly this time) when I noticed more smoke coming this time from the wire run btwn the motor and the battery compartment (about 12 inches outside the motor housing). I removed the wiring loom that I had installed and discovered a red wire burnt in 2 and a black wire burnt approx 75% thru? Also, the large black wire (approx 8 or 10 gauge braided) had a cut in it's plastic shield with exposed silver wires (must be aluminum?) but no heat marks. I put electrician's tape over cut and cut and butt spliced the 2 damaged wires but the motor still won't start? By the way, these 4 or 5 wires running from the motor to the battery compartment and terminal attachment to the ignition wires have 8 or 10 splices and I feel the wires should be renewed. <br /> I made a spark tester and plan to go test the 2 spark plug wires for spark tomorrow. If there is no spark at either wire, Is there any way I can determine just what component(s) have failed? Rectifier, coil(s), power pack? Also, I have checked my local marine hardware store (they want $72 for a new power pack...seems reasonable) but they have no info on the purchase of a replacement wiring harness. I either need ordering data for a new wiring harness or I need to get my hands on a wiring diagram that has info on the size, type, and color of wires so that I can purchase same and rewire this engine. <br /> I am a novice at working on outboard engines (this is the first one) but I am a pretty skilled hydraulic systems engineer tech (the Navy flies me all over the planet to trouble shoot their shipboard electro-hydraulic systems). I'm tooled up pretty good also. Thank you for any info you can throw my way.
The rectifier is the component that converts A/C voltage to D/C voltage to recharge the battery. A defective rectifier in itself should not cause a no spark condition on your motor, you just loose the ability to charge the battery.<br /><br />As for the other wiring problems (including the kill circuit wiring), these issues will be addressed as well in the manual. If this is a new to you motor, perhaps the previous owner did a little 're-wiring' on his own. Again the manual will sort out these issues. You'll want to pull the flywheel and have a look at the stator for any signs of a melt down or shorted wires. Testing will involve the use of a DVM (digital volt meter) and simple hand tools, which you should already have.<br /><br />Good luck and post back any questions.