Cylinder 2 & 3 not firing after ground wire mod

[Roadkill2]

I have a GS1000G 1980

I ran an extra ground wire from the battery to the Ignitor mounting bolt. I do not think this is the culprit, as i tested for continuaty before doing the mod.

Now Cylinder 2 & 3 are not firing. It rode ok for a few km's, then it started misfiring. It would randomly fire on all four for a few seconds (not fun in traffic while trying to maintain the flow of traffic) Now a cannot get spark from Cyl 2 & 3.

I have replaced the Sparkplug caps & checked HT side resistance, 32Kohm. On the Second Coil Primary winding I measure 4.4 ohm, which is also within spec. The Signal Generator pickup coils are also spot on with there resistance.

TomorRow i will "Simulate" the Pickup voltage, by doing the "1.5v Battery trick"

I suspect i must look under the cover where the Pickups are, but this seems fruitless, as Cylinders 1 & 4 still fire.

Any ideas or tricks will help.

Tomorrow i will remove the ignitor, to see if there is any visible damage.

[Steve]

I saw your question just before you edited it.

You said you had removed your "mod". Did that fix the problem?

.

[Roadkill2]

No, it did not. A tutorial i got off here (Repair and Fault finding a GS1000 Ignitor). Mentioned the "correct ground" but i tested with my Voltmeter for continuaty, before even power up the bike.

It is standard Battery Negative terminal to engine casing. I added engine casing to Ignitor mounting bolt on the left side of bike. Thinking that plate in turn would give better ground to the regulator.