coil problem?

[Guest]

I'm having a problem with my ignition on a 79 GS1000. I have a Dyna S system and the green coils. Everything was fine until the lead wire for the 2/3 cylinder pickup chaffed against the battery box and cut through. After that it would only run on 1/4 cylinders of course. I sent the unit into Dyna and they replaced it for a very reasonable cost (this is for a 20 plus year old unit). After replacing the Dyna S, she still doesn't run on 2 cylinders. If I swap the coils the loss of ignition follows the coil. So, it has to be a bad coil, right? I tested the bad coil and the good one and both have the same readings on primary and secondary tests as provided by Dyna. So both coils should be good!!! I did the rest of the Dyna S testing and all are good except for the voltage when measured at the coil negative leads when connected to the coils I have only 9.8 volts. If I disconnect the coil leads I have 12.4 volts on the leads. As I read the Dyna test procedure, I should have approximately only about 1 volt less at the coil negative than battery voltage. Anyone have any thoughts on this? Do I just get another coil and give it a shot or is there something I am missing. Thanks for any help you can give. Ray

 

[tom203]

I'm having a problem with my ignition on a 79 GS1000. I have a Dyna S system and the green coils. Everything was fine until the lead wire for the 2/3 cylinder pickup chaffed against the battery box and cut through. After that it would only run on 1/4 cylinders of course. I sent the unit into Dyna and they replaced it for a very reasonable cost (this is for a 20 plus year old unit). After replacing the Dyna S, she still doesn't run on 2 cylinders. If I swap the coils the loss of ignition follows the coil. So, it has to be a bad coil, right? I tested the bad coil and the good one and both have the same readings on primary and secondary tests as provided by Dyna. So both coils should be good!!! I did the rest of the Dyna S testing and all are good except for the voltage when measured at the coil negative leads when connected to the coils I have only 9.8 volts. If I disconnect the coil leads I have 12.4 volts on the leads. As I read the Dyna test procedure, I should have approximately only about 1 volt less at the coil negative than battery voltage. Anyone have any thoughts on this? Do I just get another coil and give it a shot or is there something I am missing. Thanks for any help you can give. Ray

Swapping the coils proves the wiring to each coil is ok, as " good" coil fires in both spots. Despite ohm readings on primary, the bad coil fails under load. Substitute with same ohm equivalent coil and you should be off.

 

[Redman]

Ray,

Any further report?

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