82 GS650g - black sparkplug #3

[Smokinapankake]

Tino,

I've got the same problem on my 84 Kat 750, only it's my #2 plug that is black and sooty. I swapped plug leads from 2 to 3 and will check tonight to see if the problem follows the lead. I'm hoping it does. Seems like you have to put a few miles on before the black sooty will burn off the plug, rather than idling in the driveway.

[Smokinapankake]

So the problem persists - black sooty on #2 plug, even with the plug leads swapped. But the strange thing is - when I was getting ready to go in to work this morning, I thought "I'll feel the exhaust pipe on #2 to see if it gets hot like the other 3". So, I fired it up, reached down and grabbed hold of 1 and 2, and yep, they both get hot at the same time/rate. So it's not my idle circuit, is it? I mean, it should be getting fuel, right? When I checked the plug yesterday I grounded #2 plug against the frame and cranked it up, got solid spark in broad daylight (in the garage with the door open, about 2:00pm) so I know that cylinder is firing. What else could it be?