CDI massive voltage drop with headlight on

Good point rg. I suppose one could epoxy the coils. I wonder if coating would make them overheat?

For everyone. The epoxy coated coils on the CDI stator are much thinner wire. The voltage is not regulated and is very high. These coils charge the capacitor in the ignition not the ignition coil. The high voltage in the cap is then blasted through the coil (capacitor discharge). This gives a sharp high voltage spark and a fast rise time to make a spark with even a fouled plug. Used allot on two-strokes.

Tom
 
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Good point rg. I suppose one could epoxy the coils. I wonder if coating would make them overheat?

For everyone. The epoxy coated coils are much thinner wire. The voltage is not regulated and is very high. These coils charge the capacitor in the ignition not the ignition coil. The high voltage in the cap is then blasted through the coil. This gives a sharp high voltage spark and a fast rise time to make a spark with even a fouled plug. Used allot on two-strokes.

Tom
Well Tom, Mrriggs has been using the Nippon Denso stator for about 10 years IIRC, and reports zero problems, so that indicates to me there are no cooling problems, with lots of resin over the coils.
On the other hand, the chinese stators (no resin over the coils) being sold by Mikesxs, HHB, XSCharge, RMstator, Electrosport and others, continue to have lots of stator failures.
The reason stators heat up/burn up, is unbalanced charging systems that cause high voltage, leading to arcing to ground. Of course
too much current being drawn by the load will also cause excessive heat. Also engine vibration will cause the individual coil wires to rub together and eventually short out producing more heat. Resin stabilizes the wires from rubbing together.
 
You have made your point rg. I guess there could be enough vibration and rubbing to short out the stator coils. Maybe it's a necessary step to soak the new stator coils with epoxy.
 
Here's a pic of a Honda OEM rotor. It might be a NIppon Denso or it could be another Japanese manufacturer. Lots of resin used. Looks like a high quality stator should look!
Honda Stator.jpg
 
I see a couple of places on this HHB stator, where the winding wire is very close to the stator steel body. Vibration and time could see the wire insulation rub through and make a short circuit to ground.
Hugh-CDI-01_LI.jpg
 
This is the response I received from the Engineer of the Manufacturer of our Stators (RMStator), as they came here to check this thread specifically and then got back to me:

Hey Hugh, happy Thanksgiving tomorrow man, hope you have a great day!

To reply to his comment:

On most of our stators with charging coils (large diameter wire) we don’t use an epoxy coating to hold the windings together. The insulation on the wire we use reacts with heat after it is wound. The stators are heated after manufacturing, this activates and softens the insulation slightly for the first time and basically sticks the wire to the neighboring turn. It results in a very solid winding. With some types of magnet wire (depending on their insulation material), they don’t stick together at all and it is required to epoxy seal the windings to prevent vibration. Not the case on these though, nothing to worry about.

Let me know if you have any more questions!


We have had a few issues with some of our stators in the last 6 years, namely a defect in the soldering done between the windings and the yellow wires. To date, and not to my knowledge, have we had issues with the windings grounding out. We've had stators cook to death when the soldered connections failed (And we've stood behind them 100% with a warranty) and we've seen them die from improper wiring techniques, bad grounds, etc.. which are typically install errors. Even then, we point out the failures, offer suggestions on how to do a more proper install, and offer components at Cost or No Cost depending on the relationship with the customer...

Hugh
 
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