bad ignition coil?
Thread Starter
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Intermediate
Joined: Mar 2023
Posts: 34
Likes: 14
From: Indiana
bad ignition coil?
1982 fxrs
evo engine
details unknown
Hello, this is in regards to a bike I inherited from my father. Im new to Harley ownership and repair. I dont know all the details of the bike.
It would not start when I first got it. Battery was bad and also was not getting proper voltage to starter and had a bad ground wire. I finally got all that sorted with a new battery, new cables, and new relay as well as rebuilt the starter while I waited on parts.
It fired right up and idled perfectly in my driveway while I cleaned up. It ran great for about half a mile and then started backfiring and died and I had to push it home.
I have spark, compression, fuel is fine. Seems to be that the ignition coil is bad. it is an Accell super coil #140108. the plug side is 29k ohms, between the positive and one of the negatives is low at 2.8 ohms, and the other side is an open circuit with flashes of low resistance. I will replace the coil and get new plug wires also.
2 questions. Do I need to replace with the same coil or is there a cheaper option? anything else I need to check in regards to the coil?
thanks
once I get it running well Ill clean it up and post some pictures
evo engine
details unknown
Hello, this is in regards to a bike I inherited from my father. Im new to Harley ownership and repair. I dont know all the details of the bike.
It would not start when I first got it. Battery was bad and also was not getting proper voltage to starter and had a bad ground wire. I finally got all that sorted with a new battery, new cables, and new relay as well as rebuilt the starter while I waited on parts.
It fired right up and idled perfectly in my driveway while I cleaned up. It ran great for about half a mile and then started backfiring and died and I had to push it home.
I have spark, compression, fuel is fine. Seems to be that the ignition coil is bad. it is an Accell super coil #140108. the plug side is 29k ohms, between the positive and one of the negatives is low at 2.8 ohms, and the other side is an open circuit with flashes of low resistance. I will replace the coil and get new plug wires also.
2 questions. Do I need to replace with the same coil or is there a cheaper option? anything else I need to check in regards to the coil?
thanks
once I get it running well Ill clean it up and post some pictures
Last edited by 18rmiller; Apr 22, 2023 at 12:24 AM.
Club Member
Joined: Mar 2009
Posts: 66,094
Likes: 51,354
From: Niles Canyon Ca.
I'd be looking at the fuel circuit before tearing into things. Old gas or a plugged petcock filter in the tank will do that to you, definitely check the filter. Get that sorted and see what happens.
Thread Starter
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Intermediate
Joined: Mar 2023
Posts: 34
Likes: 14
From: Indiana
it didnt sit that long. I have not yet but I will look at the filter. gas looks and smells fine. also fuel is getting sprayed into the carb when i twist the throttle
Grand HDF Member
Joined: Aug 2008
Posts: 3,596
Likes: 9,899
From: Florida's gorgeous East coast
There are less expensive options, for sure. Both JP Cycles and Dennis Kirk offer a feature on their websites that allows you to search for parts that specifically fit your bike. They will have less expensive, "generic" ignition coils available. Your choice.
Grand HDF Member
Joined: Apr 2007
Posts: 3,712
Likes: 3,028
From: Brighton, MI
If you have a GOOD spark, then I would look at other issues first as suggested.
Also look at threads with search word "cam sensor" and see if your issue sounds similar. At least it's worth a look. Often, electrical components fail when warm, then work fine when they cool off. Do you know what year the evo engine is?
It's kind of unusual for a coil to "go bad". Yes, they do, but, more often than not, they get blamed for electrical problems way to often and it turns out the issue was not the coil in the first place. If your ignition system is stock, then no reason a stock coil (dime a dozen) won't work.
Stay away from bargain basement made in china coils. I would rather buy a used oem from a seller on ebay who will back up the fact that a used coil is "good" than buy a new made in china one.
Also look at threads with search word "cam sensor" and see if your issue sounds similar. At least it's worth a look. Often, electrical components fail when warm, then work fine when they cool off. Do you know what year the evo engine is?
It's kind of unusual for a coil to "go bad". Yes, they do, but, more often than not, they get blamed for electrical problems way to often and it turns out the issue was not the coil in the first place. If your ignition system is stock, then no reason a stock coil (dime a dozen) won't work.
Stay away from bargain basement made in china coils. I would rather buy a used oem from a seller on ebay who will back up the fact that a used coil is "good" than buy a new made in china one.
Last edited by Yankee Dog; Apr 22, 2023 at 05:27 AM.
HDF Community Team
Joined: Dec 2005
Posts: 5,374
Likes: 2,570
From: NC USA
1982 fxrs
evo engine
details unknown
Hello, this is in regards to a bike I inherited from my father. Im new to Harley ownership and repair. I dont know all the details of the bike.
It would not start when I first got it. Battery was bad and also was not getting proper voltage to starter and had a bad ground wire. I finally got all that sorted with a new battery, new cables, and new relay as well as rebuilt the starter while I waited on parts.
It fired right up and idled perfectly in my driveway while I cleaned up. It ran great for about half a mile and then started backfiring and died and I had to push it home.
I have spark, compression, fuel is fine. Seems to be that the ignition coil is bad. it is an Accell super coil #140108. the plug side is 29k ohms, between the positive and one of the negatives is low at 2.8 ohms, and the other side is an open circuit with flashes of low resistance. I will replace the coil and get new plug wires also.
2 questions. Do I need to replace with the same coil or is there a cheaper option? anything else I need to check in regards to the coil?
thanks
once I get it running well Ill clean it up and post some pictures
evo engine
details unknown
Hello, this is in regards to a bike I inherited from my father. Im new to Harley ownership and repair. I dont know all the details of the bike.
It would not start when I first got it. Battery was bad and also was not getting proper voltage to starter and had a bad ground wire. I finally got all that sorted with a new battery, new cables, and new relay as well as rebuilt the starter while I waited on parts.
It fired right up and idled perfectly in my driveway while I cleaned up. It ran great for about half a mile and then started backfiring and died and I had to push it home.
I have spark, compression, fuel is fine. Seems to be that the ignition coil is bad. it is an Accell super coil #140108. the plug side is 29k ohms, between the positive and one of the negatives is low at 2.8 ohms, and the other side is an open circuit with flashes of low resistance. I will replace the coil and get new plug wires also.
2 questions. Do I need to replace with the same coil or is there a cheaper option? anything else I need to check in regards to the coil?
thanks
once I get it running well Ill clean it up and post some pictures
Sounds like you have a single file, aftermarket ignition. You need to take the timing cover off and let us know what's under there. Coil may not be the culprit, and there a few options if it is.
And it could be fuel related. Intake leak at the carb/manifold can and will cause those exact symptoms of running a bit, backfiring and die. What carburetor does it have?
Road Captain
Joined: Jul 2021
Posts: 605
Likes: 441
From: BRIGHTON, ENGLAND
one small & cheap tool I have found invaluable is a spark/plug/lead tester,
I got mine from Dave at Morris Magneto and works on all ignitions, he calles it a 'SPARKIE' and sells for just $32,.
all you do is hold it next to the leads or plug when turning over or running and will tell you where there is either a plug or lead down or cutting out by the LED not flshing when dead to flashing when fine,
it will work on anything from a single cylinder moped to a V12 car motor,...
highly recommended and saves hours of head scratching by elliminating the spark system fromm the equasion
Sparky (morrismagneto.com)
I got mine from Dave at Morris Magneto and works on all ignitions, he calles it a 'SPARKIE' and sells for just $32,.
all you do is hold it next to the leads or plug when turning over or running and will tell you where there is either a plug or lead down or cutting out by the LED not flshing when dead to flashing when fine,
it will work on anything from a single cylinder moped to a V12 car motor,...
highly recommended and saves hours of head scratching by elliminating the spark system fromm the equasion
Sparky (morrismagneto.com)
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Tourer
Joined: May 2011
Posts: 469
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From: Alberta
An easy way to check if you have spark and don't want to remove anything, is use a timing light. Just connect it to each plug wire, and crank the engine over. Bad coils usually only act up when the bike is at operating temp and then the bike will quit, but once it sits and cools down, it will restart. It will keep doing that type of behaviour.
Your symptoms sound like a fuel problem. Do the simple stuff first, it could be something as simple as the petcock in the wrong position, ( not enough fuel ), then disconnect the fuel line at the petcock and put a length of hose into a gas container and turn the petcock on. If you have a vacuum petcock ( known to cause problems ) you'll have to provide vacuum at the petcock to get it too flow. If nothing simple fixes your issue then it would be a good idea to take the carb off and go through it, cleaning out the jets and circuits. That way you can check things out, see what jets are in the bike, float level etc.
Your symptoms sound like a fuel problem. Do the simple stuff first, it could be something as simple as the petcock in the wrong position, ( not enough fuel ), then disconnect the fuel line at the petcock and put a length of hose into a gas container and turn the petcock on. If you have a vacuum petcock ( known to cause problems ) you'll have to provide vacuum at the petcock to get it too flow. If nothing simple fixes your issue then it would be a good idea to take the carb off and go through it, cleaning out the jets and circuits. That way you can check things out, see what jets are in the bike, float level etc.