No spark….

[amuller]

I got out my early-60s Johnson 5.5 hp which I’d gone through a couple of years ago and had been sitting. No spark. No continuity from plug connectors. It seems that the connection between the coils (new) and the wire (just the push-in spike thingy) was corroded and open. I didn’t replace the wires when I went through it.

Is this common? What sort of goop should be used to prevent corrosion?

[lindy46]

I put dielectric grease on the connection.

[fleetwin]

Those crazy spring pin connections are weak for sure…But, I wouldn’t think that would stop the engine from sparking….Nonetheless, it is sure easy enough to removed the boot/terminal, cut the wire back a bit, then reinstall…

[aquasonic]

Just as fleetwin and lindy stated, clean wire ends, dielectric grease, and the proper coil boots always work for me. I generally replace the ignition wires, but many just trim them back to expose fresh copper with good results. Dielectric grease is good because it will help prevent corrosion, and also helps prevent electrical leakage.

In regards to the coil/wire connector pins, the OMC style coils have plain spikes, whereas the Prufrex style coils have auger type connectors that require the wire to be screwed in. It seems as though all of the aftermarket overseas coils have the auger type connection these days. I recently had a motor with a set of good “spring green” OMC coils. The last person to work on it chose to skip installing the coil boots, then run it in salt water. The coils were fine but there was lots of corrosion at the coil spikes, and lots of cleaning to get them firing again.

While I’m at it, if you are short on the proper coil boots, marine heat shrink tube works well to seal up that very important connection.

• This reply was modified 4 years, 9 months ago by aquasonic.

[aquasonic]

I agree with both fleetwin and lindy. Clean wire ends, proper coil boots, and dielectric grease has worked well for me. The dielectric grease helps keep water out and the electric charge in.

The connector terminals come in two styles. The OMC spike style connector, and the Prufrex auger style connector that require twisting the wires on. It seems that all of the overseas made replacement coils have the auger style connectors these days. Both work well, but they have to be clean and corrosion free.

[amuller]

I would not have thought so either, but apparently so. I could have shifted the wire and cut off half an inch, but I decided to replace the wires. $0.79/foot at O’Reilly auto parts. Similar prices elsewhere.

Lesson learned…..

[squierka39]

I just replaced wires on a 62 Sportwin for the same reason. My motor now runs great. Mine had corrosion at the coil end. They appear to have been reused when coils were replaced. I guess I could also have cut a half inch off each end and been good but I would rather have a whole new wire without any residual corrosion. Both ends have been sealed with dielectric grease.

[amuller]

I have some learnings from this:

(1) always change the wires when renewing the coils. The wire is about $0.75/foot in bulk at auto parts stores.

(2) the boots (OMC calls them “grommets’) don’t fit tightly on the coils. I presume the older coils had a fatter molding around the connection. In any case I discarded the boots and used heat shrink of the type that has an adhesive coating on the inside. I also used some “liquid electrical tape” (think this is the same stuff OMC called “liquid neoprene”) on the wire ends before pushing them into the coil, then let them dry overnight. I hesitated to use silicone (“RTV”) as much of it has a corrosive acetic acid condensation (curing) product. The hole in the stator plate was a bit small for the heat shrinked connection to enter. Next time I might enlarge the hole a bit with a taper reamer.

Does anybody have a cost-effective source for the “sparky” plug boots?

[Mumbles]

amuller wrote:

Does anybody have a cost-effective source for the “sparky” plug boots?

These guys or Brillman might be worth a try:

https://www.mfgsupply.com/mower/mowerspark/mowersparkboots.html

Just to add my $0.02, lots of the motors I work on have seen salt water use so corrosion under the boot is a common problem. This area always gets attention as any corrosion here can cause a poor running motor after everything else has been serviced.

[kirkp]

How many do you need?
https://www.ebay.com/itm/SPARKY-SPARK-PLUG-CAP-PACK-OF-2-/232741319180

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