Coil Failure

[jmkearney]

While riding 2008 Ultra about two weeks ago engine just quit. Engine would turn over fine but no firing. Had to have bike towed to dealer. Problem was diagnosed as a defective coil. Wondering if anyone else has had same problem or heard of failures. Hopefully this was just an isolated defect. Coils are usually pretty reliable.

Jim K.

[unclepsycho]

This may not apply, since the bike is an a BMC using a revtech engine, but last year I had the front cylinder cut out and stop firing. Lucky for me it was only the front cylinder and I got home on one cylinder... and after testing the coil, it turned out to be a bad one. I dont remember what brand it was or who the factory was that manufactured the coil, but the ignition module said Revtech right on it. I replaced that too.

[frisco-rigid]

Hi Jim

Yes, coils will go bad..

Over the years I've had maybe 4 - 5 die on me..

Sometimes they just die-----often they work intermittantly, missing 2 or 3 strokes then working again and repeating for a couple days,,,,, then die..

If you have an Ohm/Volt/Amp meter you can check the coil Very easliy as per the instructions in every manual and you'll be ready the next time,, if it ever happens again..
I carry a Meter in my bags, it allows diagnosis and possible Fix on the road..

[Wrightturn]

Hey Jim,

They do fail. Both my Twin Cams have had coil replacement. The only "good news" I can offer is J&P has them 40% below dealer. They are OEM replacement.

I'm new to using this forum. I have a 02 Ultra that was recently taken out of storage and I couldn't disarm the Scorpio alarm system with the fob. I called factory tech and reprogramed but still couldn't get fob(spelling?) to work. I disconnected alarm wiring from bike wiring harness. I still can't start bike. I'm guessing that it could be the coil. I have looked through the harley manual and I can not find anything on how to test this coil. I have a testing meter, and any help would be greatly appreciated, Skydiver

[frisco-rigid]

Hi Sky

To check the coil dis-connect the coil wires and pull out the plug wires then set your meter on Lowest Ohms and check the primary resistance..
To do that you touch one meter probe to the Positive connection on the coil and the other probe to one of the Negative connections on the coil..
And then touch the Other negative connection to be sure they match closely..
They should read about 2.5 to 3.5 Ohms..

Then set the meter at the next highest Ohms setting to check the the Secondary Resistance,, that is where the Plug wires plug into.. That reading should be about 11,000 to 14,000 Ohms..

However, there could be Many other reasons the motor is not starting..
My first thought is Not the coil at this time..

What is it doing---- not even turing over Or just clicking Or nothing at all..?????

If it turns over does it feel strong or just barely.?
Do the lights work.?
Have you checked to see if the Batt has a full charge.?

Please give us More Info..

[unclepsycho]

Which modle of Scorpio was it by the way?
If that alarm has the anti hi-jack ignition disarm feature, then some wiring may have been cut to install. I am just guessing here, but double check to make sure all the factory wiring is in place? (you may have already done this, but I thought I'd mention it just in case)

[Gas Man]

You need to un-wire the anti-hijack/anti-starting of the alarm. I have installed a few of these on different bikes and if you wired it nicely that shouldn't be too hard. I would ensure that the alarm isn't the problem before I started attacking the bike itself.

Frisco-Rigid
My 02 Ultra is EFI,so it has the ignition module & coil as a combined unit. I tested the secondary with part completly removed from bike and got 6000 ohm reading. Thats well outside your listed parameters. The primary is a 4 pin connection testing between those pins reads seems to vary from .7 ohms to an over load reading on meter.
The bike is turning over strong.
The lights work.
Battery is at full charge, and was removed from bike during winter storage with trickle charger on it the whole time.
Unclepsycho,
The Scorpio alarm is the SR-1500 model. I did remove alarm from system by cutting the wire where it was inserted in the fuel pump wire behind fuse block and spliced original wire back together. It was installed by someone else before I got the bike and has been flawless till this year when it came out of storage and after battery was reinstalled the proximity sensor would set alarm off as soon as I would move into it's range. The fobe would not disarm the alarm. I contacted Scorpio as got reprograming instructions and the alarm would still not work properly, even though fobe indicated it was reprogramed correctly and bike alarm resonded with right amount of beeps and lights fashed right amount of times etc. I was then told by Scorpio to pull the 5-pin module connector and I also pulled the 4-pin module connector on the Scorpio system. I was told that there alarm was now completly removed from system and now my bike should run. The alarm would be a sperate issue at a later date since getting the bike started was the main concern now. I am 100% sure that the bike went into its long winter storage with alarm turned off.
I did check factory wiring and it seems to be in order.
Gas Man
I believe I have the alarm removed from system. I agree with your quote, so I've taken over solving this situation and any future challenges on bikes.

Thanks Guys

[Gas Man]

Can you verify spark?