No spark on number 4, looking for coils.

[Rusty_Machine]

I bought a 1979 GS550E last year and rode it for about 100 miles before putting it away for winter with no issues.

This spring I pulled it out put fresh gas in but it ran poorly. Narrowed it down to not spark on number 4. So I changed the plugs cleaned the point and put new lower resistance caps on, they looked old, to no help.

I took out the multi meter and found I had no continuity between wire 1 and 4, like I have with 2 and 3. I figured it must be a broken wire so I order those. They can in and as I'm taking the old ones out of the seemingly factory coils, the wires twisted off inside the coil.

So here I am with coils that do not seem to have replacable wires and bike that doesn't run, with still no idea why I don't have continuity between 1 and 4.

Ps. The wire was fine .

So I'm looking for a set of coils and at this point I'll just change both coils as I think it might have been an internal coil failure but all my other test points seem fine.

 

[tom203]

with still no idea why I don't have continuity between 1 and 4.

well , you found out that that the coil/plug wire connection was weak. Since you still have the points ignition setup, you might be better off looking for used coils….lots of newer versions have lower primary resistance which stress the points more…..but I’m guessing here.

 

[Nessism]

Any coils with between 4-5 ohms will work. Z1 Enterprises, Amazon, eBay, etc, have coils like these.

 

[unfocused]

I use 4.3 ohm coils from the Katana era of motorcycles. I don't use caps and run stock plugs.

 

[chuck hahn]

Try unscrewing the cap and trimming 1/4 inch off the wire and screw the cap back on. Could be as simple as a bad connection

 

[Burque73]

I bought a 1979 GS550E last year and rode it for about 100 miles before putting it away for winter with no issues.

This spring I pulled it out put fresh gas in but it ran poorly. Narrowed it down to not spark on number 4. So I changed the plugs cleaned the point and put new lower resistance caps on, they looked old, to no help.

I took out the multi meter and found I had no continuity between wire 1 and 4, like I have with 2 and 3. I figured it must be a broken wire so I order those. They can in and as I'm taking the old ones out of the seemingly factory coils, the wires twisted off inside the coil.

So here I am with coils that do not seem to have replacable wires and bike that doesn't run, with still no idea why I don't have continuity between 1 and 4.

Ps. The wire was fine .

So I'm looking for a set of coils and at this point I'll just change both coils as I think it might have been an internal coil failure but all my other test points seem fine.

Those wires can be replaced, not easily, but it's possible. The epoxy that holds the wires in can be chipped/ scraped out and new wires glued back in. There is a pin or spike in the center of the hole the wire goes in, so be careful digging the old wire out as not to damage the spike thing. I found all the stuff at the local auto parts store to do this. Will look for any pics I have of it.