How to test a coil, specifically a boyer micro power Gill coil

nezzer

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As part of my fault finding I am trying to test my coil. It was part of a Boyer Bransden Micro Power Digital Ignition Kits, KIT00303.

According to Boyer tech support, primary resistance should be 0.6 ohms. Secondary resistance should be "around 2.7k ohms".

I have tested the primary resistance by connecting my ohm meter to the two inputs on the coil, stamped on the plastic coil case as + and -. That part made sense. The coil checked out fine at .6 to .7 ohms.

Now I am trying to check the secondary resistance. How is this done?

I have tried connecting to the - input and to one of the coil outputs, the spark plug wire lead. I got 0. I tried the same thing but + instead of -. Same result. I then tried putting my ohm meter leads on the spark plug wire leads (not using + or - inputs at all). Still got 0.

Is there a trick I am missing? Does the coil need to have power applied to it for the test to work or something? I am testing this off the bike.

Thanks.
 
No, don't apply power.................resistance checks are done with no power.

If the coil has 2 high tension outputs, then that is where you measure the secondary resisitance with your meter leads. Are you using the correct meter scale? For the primary you used the lowest scale such as 20 ohms. For the secondary you want to use a higher scale such as 10K ohms.

Its hard to measure 0.6 ohms, because the meter leads are often 0.4 or 0.5 ohms. I guess you took that into consideration.
 
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Well I think that pretty much settles it, my coil is bad. Measuring from high tension lead to high tension lead gives 0 ohms. It does not even have any continuity.
 
Ok so I am getting the same reading at the secondary with my meter on rx10. However I've tried to test two other coils that I had laying around on the same settings and im still not getting a reading.. are we doing some wrong:banghead:
 
The meter I was using automatically selects the appropriate (usually) scale. I had recently tested the coils on my XS1100 and got readings. The meter is fine but in my case the coil was bad. I ended up replacing it with a cheapo GM coil and its running strong. Mounting the new coil is problematic as it is much much larger than the GILL coil and larger than the stock coil.
 
Is your meter analog or digital? With an Rx10 scale it sounds analog. I like a digital, easy to read.
Harbor Freight has a good one for less than $10, Less than $5 with a coupon. Item #90899 On the low ohm readings checking the leads by touching the probes and subtracting the reading from the read you get while checking a part to get actual readings. I have two meters. On eother meter one set of leads pre check at .1 ohms, the other set read .4 just now, usually .7. Both give the correct actual readings.
To check the secondary of a coil you need to set the R scale one setting higher than the expected reading. So on my digital meters for a 27k reading I use the 200k scale, the 20k scale will read a 0 reading, it can't read over 20k.
On the little analog meter I have it has a x10, x100 and a x1k. If I was to use this one on the secondary I would use the x1k, the highest scale.
Leo
 
I bought a new blue box because my meter read 0.6 ohms on the Gills coil primary winding but I didn't subtract the resistance of the leads so it was a bad coil. Replaced it with a Nology Profire 06D coil amd it runs better than the Gills coil ever did.
 
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