# What's the resistance of a coil?



## tav123456 (Jun 28, 2005)

I have a Honda Push Mower HR214 5.5, _I think_. Coil is TEC FL822-TM.
Anyone know what the resistance is?
I'm measuring 16.4kohms from sparkplug wire to coil laminates.
How would I measure it?

My mower has been dying after about 15mins with no spark until it cools down about 15mins later. Now it has no spark at all. I disconnected the kill switch and test it. It would not start with it disconnected and the switch tested good.
Any ideas on testing componets?

tav


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## bugman (Aug 12, 2004)

you need a new coil, its failing under heat. if it runs great, dies out and won't start till it cools down some, it sounds like it has already given up.


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## tav123456 (Jun 28, 2005)

Kinda fiqured so, but I was hoping to rule it out by testing it.


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## scrench (Dec 8, 2004)

unless the air gap is too close


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## tav123456 (Jun 28, 2005)

Well, I got it going...
I had to replace the coil. I took my coil to the Honda shop and we tested it. 

The specs for the transistor unit (coil) should be measured from the laminates to the wire cap end (or plug terminal), with the wire cap installed:

Primary side-> 1.2 (+-) 0.2 ohms - from the kill terminal on the coil to the laminates on the coil.

Secondary side-> 12.0 (+-) 2.0 ohms - from the end of the wire cap to the laminates on the coil.

Air gap for coil-> 0.4 (+-) 0.2mm _[0.016 (+-) 0.008 in]_

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My coil tested 2.5 on primary and 16.9 on the secondary.


Here is the part I didn't know-> I pulled the wire cap off and took measurements between the laminates and the end of the wire (12.15) and it appeared to be within specs, but later found out it wasn't.

I then measured the cap from one end to the other, the wire cap was 4.8 ohms, which is what a new one measured.

(Secondary measurment)
Then I measured the total resistance with the cap installed (16.99), which was out of specs.


Be-aware that the specs are the complete unit with the wire cap installed.
Because my coil was 16.99, it was out of specs and did not produce a spark.

_Thes specs were copied from a Honda service manual._
tav


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