How to test coils?

[Guest]

Hi, I'm having a hard time testing the secondary on my coils.
I have the Dyna 2.2ohm Primary and 14000 secondary.

The Primary is tested at 2.3 Ohm each.

I do not know how to test the secondary.
They say one lead goes to the post and the other to the trigger or the +12.
If I do it like that I get no reading.

If I put one lead in each output posts I get 13100ohm from both.

I'm testing them because when the engine is cold it fires perfectly but the second it warms up it stutters throughout the rev range.
The carbs are squeaky clean and synced. It starts up perfectly.

I do not know what to make of this.!?

[tom203]

Since these are dual spark plug coils, just check secondary on a coil by sticking meter probes into both plug wires- try with and without the plug caps. 13k ohms sounds reasonable to me from plug wire to plug wire.

[tom203]

As to the stuttering stuff, how quickly does this develop? Have you checked your charging system for decent output? Double checked the dyna connections?

[c&c]

I reinstalled the spark plug wires and I'm getting 30800 ohm and 30200 ohm.
When I shake the coil is goes up and down. 26000 to 40000 ohms. Both coils do it.

I decided to test the coils and wires separately.
Shaking the coils does not alter the ohm readings.

8530 ohm / 9000 ohm when shaken
8680 ohm / 9110 ohm when shaken
8170 ohm / 8500 ohm when shaken
8920 ohm / 9730 ohm when shaken

Is this normal?

Also how does one go about testing the coils when hot.
Should I just go for a ride until it starts stuttering then unplug the wires then check resistance?

[c&c]

As to the stuttering stuff, how quickly does this develop? Have you checked your charging system for decent output? Double checked the dyna connections?

It starts when the engine gets warm. The charging system is working flawlessly (knock on wood). The dyna connections seam to be OK.

[c&c]

Update:

I have finally ironed out the kinks in the misfiring, hesitation, weird noises and PIFFFFing sounds coming from my carbs. All because of misfiring.
Not only where my spark plugs dead, I had another thread on this, my spark plug wires are also crap. Every time I wiggled them the ohms reading would fluctuate, so I redid the coil terminals. That stopped the fluctuation but my freaking terminals where a tad to big. They did not fit all the way in. which caused more misfiring, More screwing around to get them in. Misfiring stopped. I have the Dyna DW600 and the specs state 250ohm /inch. After testing, mine are almost double. Yea this is so much fun . Ordered a new set that I will get next week.

So stating a quote I read on another site: If your carb problems "really" don't make sense, check the ignition system.

My endeavors are far from over. I got some hd clutch springs that solved the slipping clutch but had to swap back 3 old ones because apparently the HD springs can fuggle up and even break your clutch cable. Now that my engine pulls nicely , all that torque is making my clutch slip.

I need to find my self a sugar mommy!

[tom203]

Thanks for update- bound to help others with misfiring issues.