Green prufex coils longevity

[opposedtwin]

How long do these German made prufex coils last? How long should they last? How long have they lasted for you?

I rebuilt the magneto on my FD-11 about 6 years ago. The motor has run so nicely that i just can’t find anything about it that i don’t like. This spring it ran great like always for 3 or 4 outings. Now however, I am having some trouble with it. It won’t run well at all and it won’t get up to full rpms. So tonight i pulled the flywheel, cleaned the points (not really dirty) and checked spark. Nothing on the bottom. Top has a pretty weak whitish colored spark. The primary circuit tests ok but no continuity on the secondary circuit. Is it possible this coil is shot after only 6 years? It is my primary motor. I usually run it 10-20 times a season.

Just wondering if you guys have had these good coils go bad after a few years. I just assumed they’d outlive me. What do you think?

Scott

[chris-p]

Strange Scott, not something I have found yet. I buy the Prufrex by the truckload as well!

[Mumbles]

I’ve seen used ones starting to crack but have only come across one or two bad ones over the years. No one around here carries them so I use the BRP ones. Six years isn’t long for a coil so it may have been defective since the git go.

[opposedtwin]

Turns out the spark plug wire was where the continuity was broken, right where it connects to the coil. Lasted 6 years like that but the i suppose the vibration ultmately did it in. I’ll have to clip the wire back a bit and reconnect it. There are signs of arcing on the green plastic at the connecting point.

I have changed maybe 20 coils on these omc universal mags, so i lack the experience of some of you guys, but I have to say that for me from a reassembly stand point, that connection is kind of a weak link in the design. It’s a bit hard to stab the point into that small diameter of wire and then work the coil down into its recess and anchor it without pulling the wire away from that point.

There’s probably a smarter and more efficient way to do it, so let me know your best practices! As Ross Perot said back in ’92, "I’m all ears!"

Scott

[chris-p]

Always remove the mag plate when changing a coil. You cannot do it otherwise, not properly, no way no how.

Pull extra wire up through the hole. Add dielectric grease to the end of the wire. You then twist the coil onto the wire about 5 or 6 times. That wraps the wires around the pin, locking it on, and ensuring a good connection. Then slide the rubber holder up over the coil. Drop the coil down onto its spot. Lock down the wires and you are all done.

[crosbyman]

the last one I did I screwed the wire down on the coil pin screw as much as I could and before sliding the boot over wire & coil I filled the boot cavity with silicone hopefully to prevent corrosion, vibration "pull-out" & oxydation…. at 67 I hope it outlives me .

Joining AOMCI has priviledges 🙂

[fisherman6]

With the Prufrex coils, they have a nice snout on them where the wire slides and twist on to the spike. I also use a dab of dielectric grease on the end of the wire at the connection, but I use a short piece of marine heat shrink instead of the slide on rubber boot. Shrink the tune on there until the glue starts to ooze out then let it cool and reassemble it. This has given excellent results. The wire stays in place and it keeps contaminants out. This works with OMC coils too, but the shape is a little bit different and it doesn’t work quite as nicely.

I have also found a few of them cracked as well as the blue and light green OMC coils. The Prufrex coils seem to be quite durable from what I have found though.
-Ben

OldJohnnyRude on YouTube

[dougs-outboards]

Dougs Outboards LOVES the green coils, have bought many lots of eight. Thanks Jim for offering them, and at a reasonable price too!

[cgodfrey]

I was just about to ask – where’s the best place to buy the Prufrex branded ones?
I’m usually not picky, but I’m starting to see a strong preference among people who do a large volume of coils

[chris-p]

Jim Judkins, check the classifieds.

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