1979 GL1000 Dyna S on three cylinders

[Ruffian]

Hi,
I´ve recently got a 1979 GL1000 in pretty good mechanical condition (good compression in all 4, no smoke, good transmission etc) but it needed some care and love, mainly carb cleaning / synching, ignition timing/points etc.

Now carbs & plenum are clean and rebuilt, and I have also installed a Dyna S ignition. Problem is that I cannot make cylinder #2 fire. Went through the carbs again just in case, and nothing changed. All 4 plugs are new and firing, but one strange thing I´ve found is that the spark in the dead cylinder #2 is much stronger than the rest. If you unplug the cap, you can hear the spark. If you bridge it to the cylinder head, the spark is more than half inch long! If you just hold the plug cap with one hand and put the other hand close to a grounded surface, you get a spark! This doesn´t happen with the other plugs. No visible spark from the cap to the head when plugged. Also tried to swap connections between cylinder 1 & 2, and #2 is always the one that doesn't fire. Any thoughts? Thank you!

 

[zman]

Swap plug? or try a new plug.

 

[Ruffian]

Hi Jeff, thank you, I tried it without any improvement. Not sure if this is the cause, but there is a clear difference in the spark intensity, being the one for the dead cylinder excessively hot. No matter which wire/plug is there or if you swap them. I have also tried different coils (some standard type ones + resistor and some Magna 5 ohms), nothing changes.

 

[zman]

I dont know Dyna but is the ballast resistor supposed to come off or leave it, I`m out of ideas except to replace the dyna with points.

 

[Lowrider Bud]

When I had a problem with my Dyna ignition I removed it and reinstalled the points, and I'm still running points a years later. And yes remove the ballast resistor.

Later, Bud...

 

[Ruffian]

Thank you , guys. I tried both standard coils with resistor, and 5 ohm Magna ones without it. Same result. What I found is that the right side coil wiring (#1&2 cylinders) will deliver a much hotter spark than the other one. If you place the plugs half inch from ground, it will still spark through that gap! But then I´ve also found out that there is some "tampering" in the wiring that makes the ignition get +12v either with or without the resistor (you get +12v at both resistor wires). I´ll keep investigating on this. Anyway, I don´t see why this would make the engine run in 3 cylinders (I guess this would affect both front cylinders simultaneously). I´ll also take another shot at the carbs while out of the bike...

 

[Cobra 427 V8]

Thank you , guys. I tried both standard coils with resistor, and 5 ohm Magna ones without it. Same result. What I found is that the right side coil wiring (#1&2 cylinders) will deliver a much hotter spark than the other one. If you place the plugs half inch from ground, it will still spark through that gap! But then I´ve also found out that there is some "tampering" in the wiring that makes the ignition get +12v either with or without the resistor (you get +12v at both resistor wires). I´ll keep investigating on this. Anyway, I don´t see why this would make the engine run in 3 cylinders (I guess this would affect both front cylinders simultaneously). I´ll also take another shot at the carbs while out of the bike...

Have you tried screwing the mixture screws in on the cylinders that aren't firing , one at a time , when they are right in, if it makes no difference maybe there is no fuel from that circuit ? Cheers

 

[Ruffian]

Yes I did. Nothing changed.
What I found today is that one spark plug (mainly used in the dead cylinder) is showing random resistance values between 300 to infinite. I guess it is shorted. They're all NGK D8EA but not Japanese (made in Brazil, supposedly). I have just bought a set of Japanese ones and will try them out.