GS1100GL stumbles during cruising

[GS1100GLMLA]

One other note, I noted that I was overfilled on the oil by about 1/8 of a quart. I drained it down to just below the full mark on the site glass last night.

[GS1100GLMLA]

+1 on floats heights....sounds like fuel starvation due to the floats.... and makes more sense if you did any adjustents while cleaning them + you say shes now running lean

I actually didn't adjust the float heights when I cleaned the carbs since it ran fine before the cleaning. Just started hard. They all checked out at 7/8".

[hikermikem]

My plugs are carbon black on the shell face and dark tan on core nose. I'm running Champion N3C's.

Not familiar with those plugs, but a quick web search showed they are cross-referenced to both NGK B8ES and NGK B7ES plugs.

Not sure how one plug can cover two different heat ranges, but I would at least use the OEM specified ones, NGK B8ES I believe...

Overfilling the oil will definitely show black on the plugs. Make sure you're checking it while on level ground, on the center stand. Change out the plugs to OEM ones, and check the color after riding a bit.

As mentioned before, I would also raise the needles to reduce (eliminate) the mid-range stumble, especially with the K&N drop in filter and 4:1 pipe. If your needles aren’t adjustable, you can shim them with tiny washers. RadioShack sells a bag of assorted washers that have the size you need – I haven’t been able to source them individually anywhere. Each washer is approx. .020” thick or ½ notch.

[GS1100GLMLA]

Well, after draining the oil to just under the full mark, I took it for another spin last night and it ran fine while cruising. Can too much oil cause this?

[hikermikem]

Well, after draining the oil to just under the full mark, I took it for another spin last night and it ran fine while cruising. Can too much oil cause this?

Yes, in my experience...

Not exactly sure why, but I think too much oil in the crankcase doesn't let the head vent properly, and that extra oil finds its way into the cylinders (fouling plugs) & ends up being spit out the valve cover breather.

If your breather hose is properly connected to the airbox, I would check to see if there's any oil dripping from the bottom airbox vent.