Can someone identify this symptom.

[Paulcet]

Missing o-ring somewhere.... under the air screw maybe?

[bombjack]

Electrical issue? Bad connection somewhere?

[Homer]

It's Monday already!
Who is phone? 

[the mole]

It's Monday already!
Who is phone? 

What is fridge?
When is hairdrier? 

[Homer]

All-purpose interrogative.

[The Buddha]

Sorry guys I am tuesday. Wife and kid was weekend.

Anyway the bike had a pinhole leak from its petcock vacuum diaphragm. It was sending fuel into the carb throat with the engine running, and increasing vacuum causes an increase in the flow, and vacuum tends to be strongest @ low revs. It hence was killing the idle and low revs, get it over ~2500 and it would almost run flawlessly.

This bike was a savage, a 1 cyl, so 1 carb and it was killing it. The previous time it was a GS that I encountered this problem on. Vacuum line in a gs is off the left carb, so a fouled plug on the left carb is a good indication its a gas to vacuum side leak.

Cool.
Buddha.

[Homer]

Crap!

[bombjack]

That was my next guess.... 

[the mole]

Homer, thanks for the explanatory post. It didn't explain a damn thing, but thanks anyway!
I guess I'm just too old. 

[commuterdude]

dang i'm so pissed!  No matter what happens with anyone's bike i always say it's a bad gas tap, and this time I would have been right!  i almost said it too!

[ivany]

This bike was a savage, a 1 cyl, so 1 carb and it was killing it. The previous time it was a GS that I encountered this problem on. Vacuum line in a gs is off the left carb, so a fouled plug on the left carb is a good indication its a gas to vacuum side leak.

Cool.
Buddha.

So, I noticed that my left-hand side plug is a little browner than the right. The electrode looks fine, just the threads are more brown than the other side. I swapped the plugs (it ran fine before and after, seems to make no difference) but is this an issue, or can I forget about it?

[The Buddha]

The problem in your case could just be the floats or somehting. Vacuum to gas leaks tend to be rather severe and kill the thing @ idle.
Cool.
Buddha.

[ivany]

Should I worry about it? Or just keep riding it and whatever?

My exhausts were also a bit tight before I adjusted them (and pulled the plugs) - maybe that could do it?

[pandy]

That was my next guess.... 

+1 

Bump for the last question.

(Yes, burning1, THill is my fave...say hi to T5 for me.....I'm on intimate terms with T14   Good luck with your races!!!!! )

[multipledreamz]

Herpes?