1979 Johnson 35 HP Seahorse (35EL79) Troubleshooting powerpack, spark, ignition kill

Fellas,

I've read through many posts and can't quite seem to find an answer, so I started this post.

I'm running a 1979 Seahorse outboard, which until recently, ran great. After zooming along the river for about 5 miles, the engine bogged down as if there were no spark until it shut off. Then, wouldn't start. Upon paddling 2 miles and getting a tow from a nice river boat the remaining 3, the engine started fine.

I towed it home to begin troubleshooting, and have not been able to get it to start since.

In my troubleshooting I disconnected the battery and tested the ignition switch. Although the push-to-choke feature doesn't work on the switch anymore, the switch successfully contacts between starter and 12V and disconnects the kill wire (black/yellow) from ground while in the on position, also, it successfully contacts the kill wire back to ground when in off position.

After that series of checks, I removed the cowl and located the powerpack. The two lead cables running to each spark coil are intact. Each spark plug wire is also intact. I tested and found continuity between each of these leads from the powerpack to ground (?). I disconnected the 5-pin connector between the ignition switch and the powerpack and still continuity between the spark leads and ground.

Here's the kicker, I checked continuity between the black/yellow kill wire at the powerpack and it is connected to ground??? I'm assuming this is incorrect and means there is a short somewhere either in the powerpack or on another ignition component.

My question, if this is indeed incorrect (blk/yel wire should not be grounded at the powerpack) then what would be my next step in troubleshooting? Since this is the blk/yel lead coming off the powerpack is it the powerpack that is shot? Could there be another cause I could troubleshoot without removing the flywheel?

I do have a Johnson-related Clymer service manual but not the OMC service manual. The Clymer is a general guide that explains a lot, but does not have my particular symptom listed.

Any direction is greatly appreciated!

Best,

John

Re: 1979 Johnson 35 HP Seahorse (35EL79) Troubleshooting powerpack, spark, ignition k

Go to the CDI website and find your engine, use their troubleshooting guide to help you find your problem.

Re: 1979 Johnson 35 HP Seahorse (35EL79) Troubleshooting powerpack, spark, ignition k

Thanks Daviet. I missed that guide on my read-through of the previous posts. I'll run through the DVA resistance and voltage tests at the terminal block to see if I can identify the issue there.

Best,
John

Re: 1979 Johnson 35 HP Seahorse (35EL79) Troubleshooting powerpack, spark, ignition k

Keep us informed on your progress, someone else might have the same problem.

Re: 1979 Johnson 35 HP Seahorse (35EL79) Troubleshooting powerpack, spark, ignition k

OK, I disconnected and jumpered each wiring harness and tested resistance. All checkpoints from the CDI guide around the powerpack checked out good, including coils/stators. Furthermore, there are large voltage spikes coming off the stator when rotating the flywheel (I don't have a DVA so I only know it is large or OL value as referenced on my Fluke meter). Given that knowledge, and the fact that the powerpack is an original OMC powerpack from early 1979, I'm going to replace it with the inexpensive Sierra one from Amazon.com.

I'm also going to strip the entire engine of all the original 1979 wiring and replace with No. 14 Stranded Tinned-copper with marine-grade jacketting from Ancor. That should run about $100 parts cost and 3 hours labor if I do it point-to-point and heat shrink labels based on the original color-code.

The wire replacement will ensure all contacts to the engine block are sound, and the new powerpack is supposed to be very well-made.

I'll update if/when it works.

Thanks,
John