1990 Evinrude 25hp poor/no spark (UFI to CDI conversion)


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Mar 31, 2018
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Santa Rosa, CA
My E25TEESB has suddenly stopped sparking on both coils. I believe this year motor has an Under Flywheel Ignition setup which Evinrude only had for a few years.

I have my spark gap tester hooked up without plugs in. Sometimes on the first crank I'll see one faint spark jump across, but usually nothing.

I was suspecting a faulty kill switch. I disconnected the black/yellow wire plug to try to rule it out, same issue. I put one DMM lead on the charge coil side of the now disconnected black/yellow plug and the other lead to ground (bolt on thermostat housing). This reads about 20M ohms. Is this normal? Would you suspect a short to ground or faulty charge coil? I'm lost :LOL2: Thanks!

(Edit: Sorry if this should of been in the electrical forum)

Remove and clean each ground wire and the connection area on the block. Check spark again.
Disconnect the key switch harness from the engine at the plug and, with the spark plugs out, check for spark....keep the plugs away from the plug holes!
Tell us what you find. Your ohms check you made is not a valid check. You really need a peak reading voltmeter to check the system quickly.
Thanks Pappy.

I’ll give it a shot when I get off work today and post an update.

I’ll be annoyed/ecstatic if it ends up being something simple like dirty grounding.
Sorry for late reply, doing an update now.

Didn't help cleaning the grounds. Popped off the flywheel tonight and found this:



Looks like that coil gooped out a bit(?), and the power pack looks damaged, scraped by the flywheel. Thinking of doing the CDI conversion to get away from this UFI system: https://www.wholesalemarine.com/johnson-evinrude-cd2-usl-conversion-kit-6100-limit.html
Installed the CDI conversion kit today. I was one of the lucky ones that had to file down (per instructions) a part of the inner stator plate ring to make room for the trigger sensor, nice engineering.... I'm sure I got the wiring routing all weird too...but it fired right up with a strong spark on both coils!

Seemed like a good idea to get away from the Under Flywheel Ignition (UFI) system that they deemed unworthy after a short range of usage (1989-1992).


Not sure how I like how this power pack mounts. Is this normal for these? The wires are tight and against the block.

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