TOPIC: Troubleshooting a 73 Evinrude 85 hp

I bought a 73 evinrude 85 that had a skipping problem. Put new coils in and it ran good for a couple days. Going down the lake I thought I smelled burning plastic for a couple minutes then it went away. Coming into the dock it skipped a little then quit from no spark. Anyone know how to troubleshoot the ignition on these? I'm a little worried to replace an expensive part that may have been caused by another defective part.I think this style ignition is the same from 73 to 77.

I would wait for a reply from one of the experts, but I was having similar issues with a '79 Johnson 55 and replaced the powerpack. Smooth sailing since then. I did not have the melting plastic smell though. I take it that you did not notice anything melted?

Is the spark totally gone or just on one cylinder or bank? If the coils are good then it is probably the powerpack. you can test the coils without a meter by "moving" the coil to a different cylinder. I did it by switching around the leads coming out of the powerpack - changing the lead going to a firing cylinder to go to a non-firing cylinder and vice versa. If the non-sparking cylinder now has spark, its the powerpack. This is confirmed if the previously sparking cylinder now does not have spark. Don't forget to label the wires so that you put them back the right way after the test!!!!!

One last thing - looking at the parts on Marineengine, there is a fuse at #27. Might be worth a look, but a blown fuse is probably the symptom and not the main problem.

www.marineengine.com/parts/johnson-evinrude-parts.php?year=1973&hp=85&model=85ESL73M&manufacturer=Johnson§ion=Ignition+System

I dealt with the same problem last summer, as well. My 1973 65HP Evinrude Triumph would start fine, then would begin to spit and sputter once the engine warmed up (about a mile from the dock), then die altogether (no spark at all). I also had the faint electrical plastic smell. With mine, if I waited till back to cold (a few hours later), it would start back up, run, and do the same once the motor got up to operating temp.

Replacing the power pack on mine solved the issue. Once I removed the power pack it was evident that it was the original one that came with the motor in 1973. It had a light plastic burning smell when held to the nose. I had to slightly modify the mounting of the new one (DRILL ADDITIONAL HOLE) to mount t o my engine, but it was an easy job. Now she purrs like a kitten.......

Hope that is all you have to do.

The motor has no spark whatsoever. I did find some evidence of melted plastic under the flywheel, but I'm not sure if it is from this incident or not. Good chance though.
I can assume it's similar to testing a stator for an alternator, but I'd like to know for sure, and also what caused it. I'm a mechanic by trade but my ignition trouble shooting skills end with mid/late 60s on outboards. Not sure how to test the electronics.

Paul - I'm not a mechanic by any stretch, so you are probably more qualified than me. the powerpack is not under the flywheel, so you probably had something else get stuck.

Wiring look good? I had a mess with my 79 when figuring out the ignition problems. By fixing one thing I kept breaking the brittle wires. Maybe you have a broken wire leading to the powerpack? Did you use a meter to test for continuity?

I would put the odds on a bad powerpack at 90+%. I know that it is an expensive part to roll the dice on, but I would try it unless someone else chimes in. I don't think there is a way to test the powerpack. The other 10% is a loose / broken wire, and at least you can check for that.

Here is the diagram and #18 is your powerpack

www.marineengine.com/parts/johnson-evinrude-parts.php?year=1973&hp=85&model=85ESL73M&manufacturer=Johnson§ion=Ignition+System

I threw this in my son in laws lap as he's a mechanic also (and had more time at the moment), but neither one of us found brittle wires. Yep, you're right, the power pack isn't under the flywheel but I think the stator for the ignition is under the flywheel (# 64). I would agree with you on this normally, other than I found something melted under the flywheel. I suppose I could take a gamble on a power pack as it's much cheaper than a stator. Sure would be nice if we knew if there's a method to test both of them. If I can come up with anything I will share it with all of you. Thanks guys, I appreciate your input.

CDI Electronics has an excellent ign troubleshooting manual, you can view it online or download a copy:

www.cdielectronics.com/support/

HTH........ed

Great. Thank You!

Thanks Ed - that will be very handy as I am troubleshooting a couple of my projects.

I pulled the flywheel and found a melted stator. On to the next motor that was given to me.

Was the bad motor a long shaft? Did it have power tilt?

It's a 20 inch shaft with no power trim.

Thanks. Hope your next motor is a keeper.