Spark Plug wire patch ??

[Save Old Iron 1,566]

Has anyone ever patched a spark plug wire on a magneto based engine ?? I hate to replace the entire magneto assembly for something this simple.

The PO must have had arcing issues in the past and someone put what appears to be a pliable silicone ?? patch on the high tension lead going to the spark plug. The patch is less than perfect and on occasion will arc to the surrounding metal.

Other than replacing the magneto assembly - any suggestions ?

[JimD 3,345]

you might try some heat shrink tubing, a little larger than the plug wire. take the boot off and put the tubing over the affected area, then CAREFULLY use a torch to shrink the tube. the stuff is made for electrical connections that will be buried. don't know why it wouldn't work for this. but find a way to keep it away from the heat source that damaged it to begin with. you can find it at your local hardware store. hope this helps. :hide:

[stevasaurus 22,700]

fan...you are right on the nut

chuck...shrink tubing is the right answer for the repair :scratchead:

[bitten 134]

Another thing you can do is wrap it with rubber tape and electrical tape. I use this combo on battery chargers that put out 300 amps and havent had a problem yet.

P.J.

[ol550 830]

I don't know what style coil you have. The one in the picture is fron a K161 and I believe is the same for a K91. I have fixed several of these by pulling the wire out of the coil and using clear epoxy sealing a new wire in it. There is a piont in the wire hole that insure contact with the wire. Mike

[Save Old Iron 1,566]

Thanks all,

I was not sure that heatshrink tubing would have the dielectric strength to keep back the thousands of volts present on the spark wire.

Mike, the engine I have is the 16hp Kolher Mag on a 1987 416-8. If possible, I would like to change out the entire wire as there are some mouse nibbles closer to the mag coil itself. I'll check to see if the wire actually unplugs from the mag - I know the kill wire does, didn't try the high tension lead.

updates to follow

[Crow Horse 8]

If you try using the heat shrink tubing, it might be a good idea to use a heat gun instead of a torch. A micro torch (butane) would be another choice......

[bork 0]

There are different heat shrinks. On the boats I use a real heavy one that oozes water proofing-lish material.

[Crow Horse 8]

I believe you are referring to adhesive lined heat shrink tubing. It gives a waterproof seal as well as mechanical strength to the area. It might not be suitable to areas that are near a high heat sources unless it's shielded from the heat.......

[Save Old Iron 1,566]

Anyone know if the spark plug wire is removable from this magneto ? 1987 416-8

Thanks

[sorekiwi 761]

I havent done a Kohler coil, but I did put a new lead in a Tecumseh coil. The wire just threaded onto a little "spike" in the coil assembly, and the wire was glued. I sealed my new wire with a hot glue gun.

Granted, that tractor doesnt get a lot of use, but I've had no problems so far...

[ol550 830]

Chuck, IF it were mine I would pull that wire out and replace it. From the angle

of your pic it appears to be very similar to the ones I have replaced. Just hook your pliers on the wire close to the coil give a little twist and pull. I use clear epoxy to seal the replacement. Mike

[Save Old Iron 1,566]

Thanks guys - here is where I am at currently - I decided the high tension wire should be replaced - the "patch" just isn't going to work

here is what was under the patch

so........... I decided to check to see what type of wire was contained in the lead - turns out its stranded copper wire

I can work with that so I stripped of the silicone shell down to the magneto and removed the epoxy with a dremel miniature abrasive wheel.

Mike, Is this something that looks familiar ??

My next step will be to attempt to pull the remaining lead from the magneto shell if you believe this is what your previous attempt looked like.

Then its off to see if I can find solid core wire by the foot. :scratchead:

[bork 0]

I remember outboard shops used to have it in a roll, & had the plug end coil & boots.

[Don1977 604]

I bought a wire make up kit at NAPA for a 4 cylinder when I need new wires for my 1959 2 cylinder JD. It was 26 bucks I have enough left to do it 2 more times.

[ol550 830]

Chuck, I have never tried the job the way you are doing it. I have always been able to pull the wire with the insulation intact with no problems. I believe from what I see from your picture I would now tug at the bare wires and if they didnt come out easily I would dig out the wire insulation and see what is below. The wires I have pulled out always had a piont inside the hole but yours may have the wire attached to the windings rather than shoving the plug wire onto a pin inside the hole. I still think regardless of what is in the bottom of the hole you will be able to make a contact and be good to go. Mike

[sorekiwi 761]

Chuck, I have never tried the job the way you are doing it. I have always been able to pull the wire with the insulation intact with no problems. I believe from what I see from your picture I would now tug at the bare wires and if they didnt come out easily I would dig out the wire insulation and see what is below. The wires I have pulled out always had a piont inside the hole but yours may have the wire attached to the windings rather than shoving the plug wire onto a pin inside the hole. I still think regardless of what is in the bottom of the hole you will be able to make a contact and be good to go. Mike

Yeah, exactly what he said!!

The tecumseh one I did had some cracked up epoxy type stuff around the wire where it entered the coil, and it all kinda just broke off when I pulled the wire out.

It was a couple of years ago, but I bought the copper core wire from Napa, they sold it by the foot, and they had the terminal for the spark plug and the boot too.

[Save Old Iron 1,566]

Thanks guys,

The rational for these "baby steps" thru the repair stemmed from the fact I have a completely usable coil and here I am taking it apart to make it "better".

So... first do no harm, and drop a few troubleshooting "bread crumbs" to always give you a safe way back to where you started. I can always solder and insulate a new wire to the coil. I might not be able to repair the coil if I just pull the wire out. So I went slow.

When I get back from NAPA tomorrow , I'll hold my breath - check my wallet for a spare $60 and give it a yank.

to all and stay tuned - you may see a grown man cry :hide:

[sorekiwi 761]

I see your point - in my case, I had probably nothing to lose - the coil hadnt produced a spark in probably 20 years so I just had at it!!

Good luck!

[Save Old Iron 1,566]

Wow, 2 months have gone by since my last post on this coil !! I finally got my salamander heater fixed so back out to the workshop.

I had the opportunity today to dremel out the remaining silicone from the HT lead and sure enough, there is a metal post at the bottom of the lead cavity that a new HT wire could be fitted to. Thanks Mike (Kiwi) and OL550 for the advice. I just didn't have the heart to grab and yank out the old lead. I think if the epoxy was old and fractured enough, that technique would have worked OK too.

The picture below shows the assembly but not the post at the bottom of the cavity. I'll try to get a better picture to post.

I'll buy a new lead in the next day or so, epoxy in a new HT lead and remount to the tractor.

Stay tuned

[chris11 184]

i have solid core wire if you want it. PM me with you info

[Save Old Iron 1,566]

Chris,

that's mighty nice of you.

NAPA said they HAD coils of it years back and the local boat dealer said they same thing - everything comes pre-packaged these days.

I was looking to pick up a 5 - 6 feet of it for future needs (when the mice invade in the spring and my good mouser tomcat is still sleeping next to the fireplace).

Send me a email with the details.

Thanks again.

[chris11 184]

Chuck send me your adress in a pm and ill mail you out 6 feet. No charge, just happy to help out. :thumbs:

[dunk50 6]

And that my friends is how a tractor forum full of men with like hobbies is supposed to work. Congrats to chris and save old iron and all the rest of you that helped!! Chris ya did good!! :thumbs:

[JimD 3,345]

i'm really glad to see how this worked out, nice goin guys!! :thumbs: