Evo single fire coil options

[Spots13]

I have a Sportster with an Ultima programmable ignition. It has the Ultima coil and has started missing on the rear cylinder. It switches to the front cylinder if the plug wires are switched and everything I can find points to the shitty Ultima coil as the culprit. I’m looking to replace it and want to know what brands others have had the best luck out of. I’d rather buy once, cry once than keep replacing cheap junk. Thanks in advance and hopefully it’s ok to post this here instead of the Sportster section since this is fairly universal to Evo engines

[farmall]

Dyna coils are popular with Ultima ignitions because Ultima coils are famous for sucking. I've had no trouble with mine.

[KevinN]

I run the 3 ohm Dyna as well. Never had any problems with any Dyna products. I've been told that Ultima ignitions are re-branded Dyna but I have no proof.

[TriNortchopz]

Did you measure the resistance of the primary and secondary sides of the coil with your ohmmeter to confirm it is the coil? If so,what were the readings?

[farmall]

Resistance readings can prove a coil bad but not necessarily prove it good. A conductor may pass a resistance check but arc to ground at ignition voltages which are intended to jump gaps.

It switches to the front cylinder if the plug wires are switched

Shitcan coil. That settles it.

It's wise to have a spare tested good, or new, coil handy since they are periodic replacement items. They will not get less expensive and if you keep a Harley long-term, they will be used.

[Spots13]

Did you measure the resistance of the primary and secondary sides of the coil with your ohmmeter to confirm it is the coil? If so,what were the readings?

No I didn’t. It’s been breaking down on the rear cylinder so I checked for spark. Spark was dying intermittently. I swapped the plug wires with no other changes and it switched to the front. I checked online and as stated above the Ultima ignitions are common believed to by rebranded dynas and carry a good reputation while that Ultima coil is junk.

Resistance readings can prove a coil bad but not necessarily prove it good. A conductor may pass a resistance check but arc to ground at ignition voltages which are intended to jump gaps.


Shitcan coil. That settles it.

It's wise to have a spare tested good, or new, coil handy since they are periodic replacement items. They will not get less expensive and if you keep a Harley long-term, they will be used.

Coil is already shitcanned. I ordered a Dynatek DC5-6 single fire setup based on the recommendations here, from Ultima and from other sources.

[Sky]

If you only swapped the spark plug wires, and it changed cylinders, replace only the the spark plug wires...
Swap plug wires and it stayed, time to suspect the coil or ignition.

If you switched the signal wires and failure stayed on the same cylinder= bad coil...
If you swapped the signal wires and the failure moved, that would indicate the ignition itself.

[Spots13]

If you only swapped the spark plug wires, and it changed cylinders, replace only the the spark plug wires...
Swap plug wires and it stayed, time to suspect the coil or ignition.

If you switched the signal wires and failure stayed on the same cylinder= bad coil...
If you swapped the signal wires and the failure moved, that would indicate the ignition itself.

Plug wires are brand new accels, plugs are new as well. Once I pulled that beat to shit Ultima coil outta there and it followed the the coil output I just ordered a coil. I’ve been wrong before, but there are pages of people that have had bad experiences with that Chinese made garbage coil. So even if it does turn out to be the ignition, even though it passes the self diagnostic it runs, I’ll just have eliminated the weak part in the system. My main reason for posting was to get recommendations on coil brands because good legitimate reviews can be difficult to find and trust, and I know most 33ers have more than average experience with what works in the aftermarket

[brooklynbomber]

DC5-6 unit is great. I always chose that with my Dyna 2ki upgrades.

[horshak]

DC5-6 unit is great. I always chose that with my Dyna 2ki upgrades.

I’ve no experience with the ultama coil. But I had a similar problem with a Crane Hi4 on my evo. Like you I bought the coil first and the problem returned. It was the crane hi 4. The way we have found this problem in the past was to start the engine and direct a heat gun at the unit. Do not cook the unit but get it hot. If it’s defective the engine will start missing like the problem you described. Don’t overheat the engine. You may need to have a fan blowing on the engine while it’s running.