Author Topic: Coil Resistance  (Read 2072 times)

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Offline eastern

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Coil Resistance
« on: October 13, 2024, 12:30:36 AM »
I noticed an arc in a crack on my #1 plug wire.  For speed I picked up a set of chineseium coils stated as for CB550.  They arrived today and I hooked up the multimeter to test them before install.  Secondary coils show about 14K ohms with out caps.  OK.  But primary coils are both showing no (0) resistance, just continuity.  This is a new multimeter to me so I tested a few other items to make sure, including some resistor plugs, all 4.5K-5K ohms.  Still getting nothing on the primary coils of BOTH new coils.  Should I return these or am I missing something?  I haven't hooked them to the bike yet.  They haven't seen power.
Appreciate your insight.

(Also, plug caps with this set, 2 showed no resistance, 1 showed over 40K ohms, and 1 no continuity at all, what a mess.  But I have other caps I could use)
1974 CB550K

Offline Deltarider

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Re: Coil Resistance
« Reply #1 on: October 13, 2024, 12:41:36 AM »
Please specify what you have ordered (link), so we can check.
For measuring the primary circuit of your coils you should select LOW OHMS.
As far as the plugcaps that came with them, your measuring results seem worrying.
CB500K2-ED Excel black
"There is enough for everyone's need but not enough for anybody's greed."

Offline eastern

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Re: Coil Resistance
« Reply #2 on: October 13, 2024, 12:57:12 AM »
Measuring of plugs was fine. I verified all by measuring multiple times, installing plugs into the caps, installing caps on wires and testing overall.  2 with no resistance, one with over 40K where my meter stopped, one with no continuity.  Results were the same.

I don't have my usual multimeter where I am, this one is autoranging.  This is why I checked the a set of resistor plugs to see results, which worked at ~4.5k ohms. 

Results of primary coils though, 0 ohms, just showing continuity. The plugs I can deal with.  My concern is showing 0 resistance (on this multimeter) on the primary coil, on both units.
« Last Edit: October 13, 2024, 01:01:39 AM by eastern »
1974 CB550K

Offline eastern

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Re: Coil Resistance
« Reply #3 on: October 13, 2024, 01:10:24 AM »
Cripes, I may have answered this myself.  I think the minimum ohm on this multimeter is 1kohm (just looked at specs).  D'oh.  I'll check again once I get to my proper meter.
https://www.amazon.ca/dp/B0BLZ7GN2X?ref=ppx_yo2ov_dt_b_fed_asin_title&th=1
Review: "Item description was misleading and indicated it measured resistance. Description did not indicate the range of resistance it could measure and most multimeters start at zero ohms. This meter will read anything below 1 k ohm as zero ohms."

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« Last Edit: October 13, 2024, 01:17:26 AM by eastern »
1974 CB550K