Carbon fouling problem

[Jethro]

So Jethro, did you install the vent lines? Any change to the stutter?
Also, I forget if I asked...does the stutter get worse as the bike warms up? If you let it idle a moment, then blip the throttle (completely warmed up), do the rpm's jump up then DIP down below the normal idle? Both are richness symptoms.

Update- I finally installed the vent lines and LO AND BEHOLD they make a big difference. The bike leaves from a dead stop smooth and flawlessly. Did you expect the vent lines to make that much of a difference, Kieth? I sure didn't. I almost didn't install them as I am currently building the ultimate set of carbs for my bike. Clean as a whistle with polished caps and float bowls. I need to get o-rings from Robert.

Anyway, I rode a whole tank of gas through the bike yesterday and even after sitting at a stoplight for a few minutes, the bike pulls away smooth.

Interstingly, I had my float level tubes hooked up when I put the vent lines on, and the fuel level seems to no longer jump around when I play with the throttle. Before, I would blip the thottle and the fuel would instanly drop a little, then fill a mm too high before leveling off. The vent lines seem to slow down the rate of fuel intake/output, making the bike run smoother. Makes a difference.

 

[KEITH KRAUSE]

Update- I finally installed the vent lines and LO AND BEHOLD they make a big difference. The bike leaves from a dead stop smooth and flawlessly. Did you expect the vent lines to make that much of a difference, Kieth? I sure didn't. I almost didn't install them as I am currently building the ultimate set of carbs for my bike. Clean as a whistle with polished caps and float bowls. I need to get o-rings from Robert.

Anyway, I rode a whole tank of gas through the bike yesterday and even after sitting at a stoplight for a few minutes, the bike pulls away smooth.

Interstingly, I had my float level tubes hooked up when I put the vent lines on, and the fuel level seems to no longer jump around when I play with the throttle. Before, I would blip the thottle and the fuel would instanly drop a little, then fill a mm too high before leveling off. The vent lines seem to slow down the rate of fuel intake/output, making the bike run smoother. Makes a difference.

Yes, I did expect a noticable difference. Like my post back on the 3rd said, removing the vent lines on a bike with a stock intake will result in a rich condition, which is what you had. Your observations of how this effects the float bowl supply/fuel level makes sense. As I've tried to say many times over the last 3+ years, the floatbowl venting is very sensitive to changes. People think it's such a simple thing that it doesn't matter, but it does. As always...pods= remove vent lines, stock airbox= keep the lines on.
I've never taken off or forgotten to replace the lines on a stock bike before, so I had no "test proof" of the effects. But the bike would have to run at least somewhat rich. HOW RICH and what jetting circuit would be most effected was the question. Your test helps prooves that it is noticable.
I'm glad you mentioned the lines were removed though. After reading your posts for such a long time now I've decided you have pretty good mechanical ability and to be honest, I figured your vent lines were on after you said the bike was "completely back to stock". I wouldn't have thought otherwise to ask.
Anyway, I'm glad your bike is running well and I hope others have learned something here too.

 

[Jethro]

Go figure, make it look like the picture and it will work! I haven't had a stock airbox on either of my GS's for the past 12 years, so I really wasn't used to needing the lines. I imagined it would make a difference though- and it did. Thanks for all the help bros!