Hello,

I have a interesting problem that I am not sure if it just a result of my lack of knowledge or incorrect tools.  I have a major CT2 project that involved buying two skelton CT2 frames with three bins of parts.  I have one complete motor assembled and looking to determine the best frame to put it on...probably the one with the matching  serial number.  My problem is this.   I have two ignition coils and it seems neither of them are good or I don't the right meter to test them.   I have a RX1 - RX100k and Auto multimeter that I am using.   I get a reading for primary coil on both in the 4.9ohms range, but I also get no reading for the secondary coil on either meter.  I have tried various setting on the RX1-100 meter but still no reading for the secondary coil.  The positive is connected to the lead and the ground to the ground on the coil.   I want to test the coil before I try to fire it up so I can narrow the problems I expect will be there before I get this thing running.   Seems odd that both coils would be defective and before I buy another one I thought I'd check if it is just a knowledge or tool issue on my part.

Can anyone help me with diagnosing this one or have I got it right that they are both shot?  If so, anyone know where is the best place to get a good one. 

Thanks....

Luke.

 Here';s a screen shot of a typical coil like the CT or most of the magneto type. Looks like there should be a definite connection between primary & secondary, well i've always assumed that. I'm sure though that i had one that worked despite 'that' no through connection & seems unlikely you'd have two faulty coils. I'd just try it for spark when you get 'that far'. Mind you i'm talking rubbish as have to have a connection to earth or through the primary for the secondary part. Should have about 5000 on the secondary so crank the meter up high--RX10,000. Bet it works. Cheers. Woops, screen shot coming. New skill for me but might need to expand it up.

Unscrew the plug cap from the wire and test it separately. 

You should get a reading from coil ground to spark plug wire.

Hey Mark.  I did try that as described in the manual.  I also poked the cable closer to the capacity in case there is a short along the way.   Unless this guy before me was collecting defective coils I must be missing something.   Any other thoughts?

Is this maybe one of those BR8ES vs B8ES plugs issues that could cause this?    I have been looking for B8ES plugs and couldn't find any and was thinking the BR8ES will work.   Is this a bad idea?

Reading from plug lead to the mounting bolts or plug lead to primary side would look the same on the 10,000 scale as adding 4.9 ohms of the primary into 5000 of the secondary wouldn't be discernible in the grand scheme of things & look much the same but is confirming contact right through primary & secondary. i think.!!

The two windings share a common ground in the magneto ignition coils, so yes on a single primary wire ignition coil you can read both together.

This won't work on the 12v battery ignition coils with two primary wires (Battery + and points)

A resistor plug is not likely to damage parts...  it just robs a little spark energy.  Just use a non-resistor cap with the BR plug.
Likely your previous owner had a bad coil and bought another one and it was bad.  Has happened many times on here even with new coils from ebay. 
I must be very lucky as I've only ever run across one magneto ignition coil that was bad.

P.S.  Poking the plug wire further down is not a great idea...  the insulation is thick for a reason.  Even if only a pin hole the high voltage can and will leak through the hole if given a chance to get to ground easier that way.

Great feedback.  Bottom line it looks like a replacement is the solution if I understand correctly?

If you are testing it the way you described it sounds like the secondary windings are "open". 

Posting pictures of how you are testing would help if you're worried you're doing it wrong.  Make sure if you have a choice of scales to select the different options to see if you get any readings.