Coil testing: What am I doing wrong?

[Kent763]

I feel like kind of an idiot but maybe someone can point me in the right direction.

I'm trying to diagnose the two inboard cylinders not firing. Since they both run off the same coil that was my first guess. I pulled the plugs and I seem to be getting good spark but better to check I figured.

Testing the spade terminals on the coils I get 5 ohms on each. Testing plug cap to plug cap I get... nothing. No reading at all on either coil. I pulled the plug caps off the wires and tried testing them for resistance and got no reading again. Testing between the plug wires themselves with the caps off still gets me no reading. I'm at a loss here.

 

[posplayr]

I welcome aboard; I see this is your first post. The simplest thing to do if #2 and #3 are not firing is to move the firing 1-4 coil and wires to the 2-3 plugs. If it still doesnt fire, then it is your ignitor/points. If it does work then it is your 2-3 coil/plugs. If you get this far then You could do could also swap coil wires around to determine if it is coils or wires.

I'm not sure what a plug cap is?

Off hand dont know what the measurements are for secondard bt primary should be 3-5 ohms. Do you have a manual?

Good luck.

 

[Kent763]

Yes, I have the manual of BikeCliff's site. I should have said plug boot instead of plug cap.

Edit: Just to be clear I know what the resistance readings should be. I'm just trying to figure out why I'm getting absolutely zero reading. It's not reading open or reading any resistance. It's like I'm holding the probes up in the air.

 

[posplayr]

Yes, I have the manual of BikeCliff's site. I should have said plug boot instead of plug cap.

Edit: Just to be clear I know what the resistance readings should be. I'm just trying to figure out why I'm getting absolutely zero reading. It's not reading open or reading any resistance. It's like I'm holding the probes up in the air.

that means high resistance. If you are on a low ohm scale it might not register at all.