No voltage at points for cyl 1 and 4 on 79 GS 550

[Guest]

I hooked up the old points plate as my Dyna is off for warranty. Ran fine for a short period of time then dropped to two cylinders. I replaced the points today and had voltage at both points while I was gapping them with the feeler gauge. I fired up the bike and sounded like it was only running on 2 cyl. Put the test light back down and only 2/3 had voltage while 1/4 had nothing again. As a result I have no voltage going through the white wire up to the coil and am not getting spark.

I'm kind of baffled as to what I should be checking? Not sure why it would work when I first put them on but immediately after running for a second I cannot get voltage anymore?

Thoughts?

Cheers,

[tkent02]

The likely place power could go to one coil and not the other is after the orange positive wire splits to go to both coils. That wire could be open, could also be touching the frame or something. Have seen the joint where that wire goes into the coil go bad too. The other option is the coil itself but that's not likely if it was just running on four.

Just get your meter out and start poking around in there. It's a very simple circuit, you will find it.

You have it backward, voltage doesn't go up to the coils, it comes from the orange wire, splits to go to the two coils, goes through the coil, down to the points, through the points to ground when the points are closed. Check also that the capacitors are connected right, not shorted and not open.

[pmac]

Thanks for the reply. It was a bad secondary in the coil I had on there, swapped it out and worked perfect. Had her out for the first ride since last spring today, couldn't wipe the smile off my face!

Cheers,
Preston