Bad coil ?

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willowtide

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Hi, First time here. Hope i am where i should be. I collect and use older Xl12, Super xl12, Old Blue and Big Reds, etc. I'm having a loss of fire with a Old Blue ut# 10045F Serial # HR2670581 Is there a way to test this coil? Is there a place where one can be purchased with out having to sell my truck to pay for it? Saw has had a very minimal amount of use and i have every part spotless. Nothing to the plug. Thanks Steve
 
Welcome aboard!

Probably, that’s a common pattern failure, assuming it’s the electronic coil. Only other test is to disconnect the kill wire & recheck for spark. Could try to bake it in a toaster oven at 225F for 4-6 hours to see if it revives.

https://www.partstree.com/parts/homelite-a94605s/
Fleabay has had them in reproduction styles for $50-75. Make sure you check your existing manufacturer i.e. Wico, Phelon/Repco, etc. & then match up for operation.

That’s a lot cheaper than a new Stihl 056 SEM coil at over $200...but you could always scrap your saw out if it’s not worth it to you.
 
check for resistance on the primary and secondary side. I can’t remember what they are but compare to your other running XL saws.
If you measure the coil on the secondary and it’s open, check where the plug wire screws in to the coil and where it connect to the plug cap. I’ve had the cap connection lose its connect with the wire and had the plug wire needing to be reseated in the coil.
The resistance readings will tell you if it’s a good coil or if you’ve lost one of the windings. Troubleshooting the plug wire will tell you if it’s lost connection and needs to be repaired. Unplugging the kill switch will tell you nothing about the coil but can indicate the switch is bad. Best way to test your switch is using the meter and testing continuity to ground or lack there of.
 
Welcome aboard!

Probably, that’s a common pattern failure, assuming it’s the electronic coil. Only other test is to disconnect the kill wire & recheck for spark. Could try to bake it in a toaster oven at 225F for 4-6 hours to see if it revives.

https://www.partstree.com/parts/homelite-a94605s/
Fleabay has had them in reproduction styles for $50-75. Make sure you check your existing manufacturer i.e. Wico, Phelon/Repco, etc. & then match up for operation.

That’s a lot cheaper than a new Stihl 056 SEM coil at over $200...but you could always scrap your saw out if it’s not worth it to you.
I baked it as you instructed for 7 hours. Works like a new one would. Was this a internal moisture issue? Thanks The information here is great.
 
Good deal.
Supposedly it is moisture or condensate on all the fine coated wire insulation, and it’s best to reseal the coil (black portion) while warm with clear acrylic via spray can.

Any visible cracks need sealed with JB Weld or epoxy. Older green Johnson & Evinrude boat engine coils, plus the Lawn Boy mowers were bad about cracking.
 
Any OMC outboards from 1952 untill the 1970s with pink coils which equals about 90 percent of them will have cracked coils the early LawnBoy coils were the same.I have filled the cracks up with silicone several times with out issues.Some coils are to badly cracked to bother plus coils are dirt cheap now days.If you buy Omc coils try to get the green made in Germany ones.
Kash
 

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