Aldeer.com Forums Alabama Deer Talk Aldeer General Forum Ask aldeer: Coil Killing Chainsaw

Going on the theory that somebody on aldeer knows the answer to any question; I would be pulling my hair out over this thing but my hair is too short to get a hold of it.

So I was cleaning up some trees in my yard and my 1990s model Homelite Super XL wouldn't crank back after I took a short break. I bought it new and have taken good care of it over the years and thought there was a good chance it would last me as long as I am able to run one, which probably isn't much longer. I guess the hardest it was ever used was when the men at my church used to cut firewood for several widows. The old Homelite wasn't as good as the pro level Stihl that one guy had, but it was miles better than the homeowner junk that most of them used. I sure wanted to keep it running, but I don't know anyone around here who would work on it, so I guess it's figure it out myself or go buy another one.

It was apparent that it wasn't firing, so I first replaced the spark plug and that didn't change anything. It's electronic ignition, so I guessed that it was the coil. I have an XL12 that's been sitting under the shed for 23 years, so I robbed the coil from it and she fired right up. I shut it down to adjust the chain and then it wouldn't crank back. I fooled with it for several hours, and that coil never fired again. I thought that all those years of sitting up might have damaged the coil in some way, but it seemed strange it would work for a while and then die.

So next I bought an aftermarket coil off Amazon and put it on yesterday. I gave it a pull and once again it fired right up. It was nearly dark so I shut it down and went back out this morning to finish my work. And it wouldn't fire a lick. I've tested it with the spark plug removed and it doesn't fire at all. I tried it with the kill switch disconnected and it didn't matter. It's like something in the saw is killing the new coils as soon as it cranks, but I've never heard of such a thing. Is it possible? Anyone got any ideas to try? Thanks for any help.

😟 I feel your pain. No ideas here.

My guess is there is bare place on wire an When u change coils u move it an when running it vibrates an grounds out somewhere . Possibly new coil is bad also .bout all i can come up with on that . I had issue on dirt bike fouling plugs so I thought . Every time I put new plug in I would twist plug cap on . While ridding it would vibrate around an ground out on motor mount . Had a pin hole in plug cap . Would never found it if I didn’t start bike one night after dark an seen it arcing off plug cap.

Yes a short to ground is about the only thing I can think of that might cause that. It wouldn't have to be a bare wire either. Just a thin place in the insulation will let the high voltage arc to ground. Look for black spots along the wire path. But on further thought, you would think it would quit while running if that was it.

I reckon the magnita could be derective some way killing the coils. Ground wire sounds reasonable but how does it fix itself each time you change the coil just long enough to crank once? That dont make sense.

Thanks for all the replies. I am not much of a mechanic, but I had never heard of anything that could damage a coil like this. I guess the other possibility is that the saw isn't damaging the coil and it's just a coincidence that both of them quit like they did. I didn't do anything else to the saw after installing the new coil from Amazon. I put it on, cranked the saw, shut it down, and set it in the shed. I didn't do anything that could have shifted a wire around.

Then I took it out this morning and I could tell the first pull that it wasn't firing. It had cranked instantly yesterday; like right at the beginning of the first pull. You can tell when the ignition on a saw is just right, and it was as good as it gets yesterday. I can't imagine what could cause it to do this. Oh well, guess I'll go buy a new saw.

You might take off the magnita, clean it up and put it back on there. Ive never heard of one going bad but i guess its possible. Ive also never heard of coils going out repeatedly on one crank. Sounds like you didnt even ru the saw for any amount of time. So the problem is likely happening during the cranking process?

It aint got no gas innit.

That's along the lines of what I was thinking, but now another chapter in the mystery.

I decided to remove the coil and reinstall one more time, but this time I didn't hook up the kill switch and it fired right up. I used it for about 10 minutes and it ran great.

I am suspecting that the whole problem is in the kill switch itself; it's just intermittent and happened to let it work after putting on the new coils. Does that sound right? That makes more sense than the saw somehow destroying coils, and it's apparent that the new coil is ok anyway.

I guess I can rob the kill switch off the XL12, but I'm gonna just run it without one for a while and make sure that's the problem. Thanks again for all the help!

I'd bet you found it. I hate intermittents!

Magnita = Magneto? . . .or is that some fancy part only the pro saws have?

Same, i jyst cant spell.....Its about got to be in the kill switxh

Remove the wires from the kill switch and tie them together. If it runs you can always stop it by pulling out the choke.

Dang I thought I had been spelling magneto wrong all my life. 🤣