Testing coils for idjuts

Mikey

got muscles in his head that ain't never been used
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I just wanted to post a video of me trying to test a suspected bad coil but I'll try pictures first
I believe my VOM tester must be bad because when I set it on Ohms and turn it on It reads 1 before anything is connected to it
Anyway heres a few photos first one is just the meter turned on with it not being connected to any thing and it reads 1
Second PIcture is the meters negative side on the brown wire and the positive connected on the orange wire reading 00.0
3rd picture ground is on the brown / ground wire and the red/ hot wire to the spike where the plug wires screws onto reading 8.3
I would guess it's time to get a new VOM meter
It will measure AC and DC voltage just fine and zero out like it should
 

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Last edited:
Reading 1 with the leads not touching anything is normal.
Primary should read about 3.9Ω Book says ± 20% (that's the brown to orange wire)
Secondary should be 8.0KΩ. Again, ± 20% (that's orange to the HT terminal ( hole))


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Put the meter on the 20k scale.
Now, touch one of the mounting lugs with one lead and (in turn) the brown and orange with the other. Do NOT touch either lead or lug with your fingers.... that will throw your reading off.
You should see 1 on the meter... just like without the leads touching. We're checking here to make sure the coil isn't shorted internally.
 
I'm going to bookmark and print this out
When it was at 1 with nothing connected I was a tad concerened
Got new points coming in the next few days
Thanks Jim I am moving forewords again
 
Taking the other coil off and testing it took minutes
I could have used this website and all you guys help 5-6 years ago
Putzing with this 73 will make it a breeze going through the 75 and checking it all again
And for all you new folks hanging around the fringes of the website join up you don't need to pay to sign up
Join the club
 
But here's the thing with testing cold coils - they may test fine but still be bad because they only act up once hot. It is a step in the right direction if they test OK like this, but not a 100% guarantee they're good.
 
...which is why I routinely replace older coils. I consider it a solid investment.

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I just want to eliminate as many problems to get this bike on the road ahead of time
It's nothing better than take a bike out of the garage
This is a bike I want to sell to some young guy/gal to get them interested in 650s
With the understanding that it needs maintenance
Good point though I'll point out these bikes aren't just fill em up and go
 
But here's the thing with testing cold coils - they may test fine but still be bad because they only act up once hot. It is a step in the right direction if they test OK like this, but not a 100% guarantee they're good.
they can also test fine but be bad because high voltage can jump internally, which won't happen with the test voltage from the meter of course. all of mine that failed were like that. an explanation for how they "weaken"
 
They both tested good
When I get new points it's time to fire it up and see
 
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