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Current drawn by the ignition coils

Posted: Sun Sep 02, 2018 7:24 pm
by Frank.61
Maybe an odd question: has anyone ever measured the current drawn by the ignition coils? :?:

Frank
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Re: Current drawn by the ignition coils

Posted: Sun Sep 02, 2018 11:20 pm
by Mc tool
I have not measured the actual current draw but the stock coils have bugger all resistance ( 0.34 ohm) so I would say its fairly high , but then the dwell time ( the time the current actually flows because the coils are switched on and off so the current flow is not continual ) must be reasonably short. You could put an amp meter in series with the coil but I doubt that it would tell you anything useful as the coil powers on and off 100 times per second at 6000rpm and the meter wont display that fast . You could hook a coil up to a battery with the amp meter in series and that would tell you the continual current flow but again not all that useful. To get a accurate idea of whats really going on would require an oscilloscope and the nouse to figure out what its telling you...... any how ,if your thinking about fitting new coils , Dyna do a suitable replacement but you would have to do a search here as others have done this but I cant remember what coils they used.
Hamish

Re: Current drawn by the ignition coils

Posted: Mon Sep 03, 2018 1:42 am
by Frank.61
Yeah, I was also afraid that you would need an oscilloscope for it.
I was curious which wire diameter I could take the best.
A specialist told me to keep 5A per square millimeter (17awg) as a maximum for motorcycle wire loom.
I have 3ohm Dynatek coils but have no idea what they actually draw during the 360 degrees cycles.
Just curious ...


Frank

Re: Current drawn by the ignition coils

Posted: Mon Sep 03, 2018 8:35 am
by Derek
For fuse purposes you need to look at the continuous current being drawn at switch on when the engine isn't running. A 3Ω coil will draw approx 4 amps, so 2 coils will pull 8A. When the engine is running, as stated above, the current draw will be much less.

Re: Current drawn by the ignition coils

Posted: Mon Sep 10, 2018 8:58 pm
by Mark
California Cycleworks designed a coil replacement kit that should work and fit for 750 Pasos with the Kokusan ignition system:

http://ca-cycleworks.com/ca-cycleworks- ... ls/2vcoils

About a decade ago I installed green 3ohm dynacoils, had a bracket fabricated and used Magnecor ignition leads - the bike ran significantly better thereafter.

Cheers,

Mark