how to test a coil - logistical problem

My 90 VFR has been sitting for 4 years. Ran good when parked. Two sets of carbs have been cleaned by an expert. Valves checked, plugs replaced, compression tested by me. Trying to get back on the road and it varies from not starting to running like crap, barely at all. Switching between sets of carbs may or my not correlate with running bad or not at all. While running like crap, the rear pipes are cold. So I checked the rear coils with my nice new Klein meter, after reading my factory VFR service manual and my factory general service manual.

Primary test was good, between the two small wire terminals on the coil. Secondary test, measuring from the end of the sparkplug wire to either of the primary wires read zero. Wasn't sure my meter lead was making good contact with the terminal in the plug cap, so I took the plug wire off to test at the coil end. My test lead doesn't reach the bottom of the connection socket. I inserted a punch into the socket to reach the spike at the bottom and measured. Zero. For confirmation, I did the same on a known good front coil. Still zero, so I know my test method is faulty.

Am I measuring between the right things? Sparkplug connection and the primary wires on the coil? What's the best way to make a good connection? Do I need to find a set of unusually long test probes?

I'm going to go try it with the plug wire reinstalled and the punch stuck into the spark plug terminal,

The bike has been run occasionally when parked for the last year or so, much better than it is now, but I have Stabil in the gas and ran the carbs dry after running it, so they should be OK. I might send the carbs out for re-cleaning if this gets me nowhere.

thanks
kevin

 

My method was OK, but it looks like my coils are all dead. I can get a reading from the removed plug wire, but with it connected to the coil I get nothing.

So how did I ruin the coils? Something I did with a battery charger? Left the ignition switch on?

 

did you leave the ignition switch on?

 

not likely 4 coils just went bad, gotta be something else. test meter must be set to the correct range to get good results. never mind the meter tests, do you get sparks on the rear plugs ?

some starting spray can help sort out problems of carbs or sparks being bad.

 

When checking the Secondary side of the coils and HT lead, did you change your meter Ohms range to 200k ?
Service Manual states between the spark plug connection on the HT lead and to the other side of the Secondary Coil should be between 17k to 24k ohms!

You can remove the HT lead from the coil and measure its resistance probing both ends of the HT lead, you should see between 3k - 4k ohms.
Even a screwdriver or similar or some thick copper wire making contact with the plug cap, then with one of your meter leads clipped or held to it should do.

Leaving the Igniton On, if it was to do any damage, that could only be to the Primary Coil, you mentioned that all Primaries measured ok.

Agree with Squirrelman - not making any sense that all four coils could be faulty. Important to establish what cylinders are or are not sparking.

Make sure you are seeing 12v on each coil at the Black/White with Ignition to On.

The rear pipes being cold might mean cylinders 1 and 3 are not firing, so check the 1-3 ignition pulse generator coil resistance and make sure of good continuity of its wiring up to the ICM. Make sure the 4P Black connector for the Ignition Pulse Generators is clean and connections are good.