DYNA 3 ohm coil question

Hi, jacked the other coli repair thread.
Question? The bar? stem? or whatever you call it, the mount in the center of this coil is loose.
It can be tapped back and forth a little. i moved it a 1/8" at most. I know they are epoxied around at the start of moulding it to produce.
Been sitting for 16 years. Got burned buying a bad Ignition DYNA S. One of the pickups were bad. At least I got to use the nice copper core Accel yellow wires. Glad I never sold them on ebay. I would have unknowingly sold the coils.
But they might be good? Any? Thing?
I never was good at electrical , OHMS etc.
I have a digital meter, scale goes 200 , (2 audable), 20, 200, 20M- highest
But each coil do the same with different settings. The 2 audable is continuity. Then higher up it goes to 4.4 ? the lowest set goes 000
I don't and never could figure out ohms?
Where is (Mfolks?) He always is the residential electrical engineer

The big problem is if the core slides enough to let the mounting bolts touch the wire scews. Use a plastic sleeve around the standoff, or even a strong plastic standoff, as an insulator to prevent shorting.

The middle part is the laminated iron core of the transformer. Being a bit loose shouldn't hurt performance but as pointed out, make sure the coil terminals can't ground out.

If you want you could Superglue the core to stop it from moving.

z1kzonly wrote: But they might be good? Any? Thing?
I never was good at electrical , OHMS etc.]

There really is no way to properly test an old coil with an Ohm meter. It won't detect the typical "arc over" internal shorts these HV transformers develop with use. I have a really bad attitude about old coils because two in a row gave me serious grief.

bountyhunter wrote:

z1kzonly wrote: But they might be good? Any? Thing?
I never was good at electrical , OHMS etc.]

There really is no way to properly test an old coil with an Ohm meter. It won't detect the typical "arc over" internal shorts these HV transformers develop with use. I have a really bad attitude about old coils because two in a row gave me serious grief.

Any coil can be checked out of car. Install spark plugs and connect them together (threads). Momentarily connect primary coil to a battery and watch for spark.
You can also use some wire to connect coil mounting holes to battery.
You also check spark on bike w/o any tester,



picture

That does nothing for testing under load.
Steve

Hey Car5, Me and Steve know Car 54! :laugh:
It's about time you put an engine on that bicycle in your avatar!
Thanks for the tip. I have not used some of my parts for 20 years. So if I can just get that simple spark. I will mount the coils.
Then worry about how they work out on the street or when they get hot later on.
This gives me a starting point.
Thanks

Yeah, the walk or ride of shame on two cylinders hoping to get home. :lol: It's easy, just take the tank off and put on a spare set while it's HOT (if you have them) or order some NEW ones while kicking yourself for being so cheap. :dry:
Steve

Some coils might not even give a spark without a condenser in that simple setup. And like Steve says, it doesn't really stress the coil like the bike would. It does test some aspects, but a more throrough test is needed to safely say the coil is good (and won't get you stranded).

z1kzonly wrote: Hey Car5, Me and Steve know Car 54! :laugh:
It's about time you put an engine on that bicycle in your avatar!
Thanks for the tip. I have not used some of my parts for 20 years. So if I can just get that simple spark. I will mount the coils.
Then worry about how they work out on the street or when they get hot later on.
This gives me a starting point.
Thanks

"Car 54 where are you???? Ooh,ooh,ooh :lol: :lol:
Steve

I've been working on a new tester design for a few days. Here's how to stress test a coil. (This is a car coil, which is usually a little more impressive than bike coils. Not because each spark has more energy, but because it can be cranked easily to 20,000 sparks per minute. Slower bike coils are really only good to about 10,000, all else being equal.)

Notice when the frequency cranks up, the sparks actually extend their distance probably to over an inch in order to find fresh metal to arc to. Or maybe the air is drier where it was heated so it is seeking a different path? I'm not sure what the reason, but this is typical. At very slow speed, the sparks will usually take the shortest path over and over.

Ooh.ooh,ooh, Cool
Steve