Ignition coil test... What does it mean?

[choptrees]

Following this video I tested the coils on my GT550: http://youtu.be/rRQ45lT2d3c" onclick="window.open(this.href);return false;. I've got no spark, have tested all connections with a battery connected with a result of 12.5 V across the board. So I decided to test the resistance in the coils.

I tested primary resistance, 200 ohm setting on the multimeter. I think the black/yellow wire is ground? I got nothing by testing that wire against the orange wires. I tried all combinations. The only result I get is testing the solid black wire against one of the orange wires - I got 4.0 ohms. All other combinations gave a result of 1.

Then I connected the multimeter to the HT lead and the solid black wire in the plug. The only reading I got was 17,000 ohms on the HT lead for the outer cylinder. Readings from the black wire to other HT leads were all 1. I got a reading from the white wire to the HT lead on the inner cylinder, again 17,000 ohms. I got no readings on the middle cylinder.

Now it seems to me I need a new set of coils? Or is this normal? If not normal I've read about folks fitting aftermarket coils. Any one have any recommendations?

[pull the wire]

are you testing the coils on the bike or off the bike?

[choptrees]

On the bike

[pull the wire]

For the primary resistance test, you must disconnect the coil connector and the spark plug wires at the plugs to do a proper coil test. If you observe the coil connector, you will see which color wires correspond to each of the 3 coils. If it is wired up correctly, you should have 3 orange wires in a row on 1 side of the connector to the coil and opposite the orange wires a white left coil, then a black/white center coil and a black for the right coil. With the ignition off, connect your meter to the orange and other color lead for each individual coil at the coil connector. You should see around 5 ohms for each coil.

Remove the spark plug caps and connect one of the meter leads inside the coil wire spark plug end and the other lead to orange wire at the connector for that coil. you should see around 12K ohms.

Check the resistance of your spark plug caps. Insert one meter lead securely into the spark plug side of the spark plug cap and the other meter lead to the opposite end of the spark plug cap. Some spark plug caps (depending if they are stock or replacements) should read around 5k ohms, 10k ohms, or near 0 ohms. Stock plug caps are usually 5k to 10k resistor type.

Hope this helps!!!

[choptrees]

For the primary resistance test, you must disconnect the coil connector and the spark plug wires at the plugs to do a proper coil test. If you observe the coil connector, you will see which color wires correspond to each of the 3 coils. If it is wired up correctly, you should have 3 orange wires in a row on 1 side of the connector to the coil and opposite the orange wires a white left coil, then a black/white center coil and a black for the right coil. With the ignition off, connect your meter to the orange and other color lead for each individual coil at the coil connector. You should see around 5 ohms for each coil.

I did this test. I got 4.0 ohms for all three.

Remove the spark plug caps and connect one of the meter leads inside the coil wire spark plug end and the other lead to orange wire at the connector for that coil. you should see around 12K ohms.

Did this also, I get 17,000 for the inner coil and again for the outer coil. The middle coil didn't register, stayed at 1.

Check the resistance of your spark plug caps. Insert one meter lead securely into the spark plug side of the spark plug cap and the other meter lead to the opposite end of the spark plug cap. Some spark plug caps (depending if they are stock or replacements) should read around 5k ohms, 10k ohms, or near 0 ohms. Stock plug caps are usually 5k to 10k resistor type.

I tested the caps, got 8230 for the inner cap, 8420 for the outer one. Then 1 for the inner coil. I also tested the resistance of the middle coil without the cap. It gave me a result of 8000 ohms.

So I'm guessing the middle coil is pooched? Now time to check resistance in stator and also check the point gaps, there's no spark when the points are open either. The weird thing in all of this is the plugs were sparking initially and are not now. There was a burning smell and then it all went dead!

Hope this helps!!!

It sure does! Thanks so much. Love these forums because it seems the usual wise ass folks are too busy loving their crotch rockets to bother fixing up the good bikes!

[pearljam724]

Hey, leave the sportbikes alone. Had you ever grown up around, owned or track ridden one. I guarantee you would feel differently about them. They are incredible motorcycles, just like our vintage ones. But, in totally different aspects. The bikes can't help that they are owned and operated by a majority of young idiots on public streets. Lol ! I'm glad you posted this thread, as my questions have been answered to wiring up new coils and testing my old ones. Thank you. Boy, does the words crotch rocket make me cringe.

[choptrees]

Hey, leave the sportbikes alone. Had you ever grown up around, owned or track ridden one. I guarantee you would feel differently about them. They are incredible motorcycles, just like our vintage ones. But, in totally different aspects. The bikes can't help that they are owned and operated by a majority of young idiots on public streets. Lol ! I'm glad you posted this thread, as my questions have been answered to wiring up new coils and testing my old ones. Thank you. Boy, does the words crotch rocket make me cringe.

I owned a ZX6 a few years back... All said with tongue in cheek! Good to know my dumb questions are helping others!