idle creep / vacuum leak in carbs

[tab1324]

Ok, I've read all the vacuum leak threads and idle creep threads and cannot quite find the answer..

I've got 79 standard XS1100 with pods. Where do the top carb tee connections go to if not using an airbox? The petcocks?

Also, the idle creeps up when cold but the boots are good (tried with other carbs). Where do I start to look on the carbs for problems. They've been triple cleaned, new needle valves installed, diaphragms are good...

Thanks,

Tom B.

[tab1324]

I should have mentioned, these carbs have a plastic cap on the idle mixture screws that only allow it to move through 120 degrees or so. Do they get removed for further adjustment? I'm used to my 82' XJ but not this bike.

Thanks,

Tom B.

[egsols]

The upper tees on the 79 are designed to vent the bowls. Now that you can't vent to the airbox you need to ensure that the lines can still vent but do not get any dirt in them or it will find its way back into the carbs. I think there is a solution somewhere on the forum where someone has put a filter on the end of the vent lines. (Allows venting and keeps dirt out)

If you have played with the idle mixture then you will most likely need to perform a sync on the carbs. You may also have to start with a readjusment of the idle mixture before syncing, i.e. all the way in (lightly) then back out 1 1/4 turns. (Me thinks)

[prometheus578]

"Tee Time."

The top carb lines (T's) go to atmosphere, if not the airbox.
These are your float bowl vent lines and they must remain open. Some people make little filters for them you keep the Mud Wasps out, etc, but they must stay open.
The little plastic caps are so people can't dick with the mixture and ruin the ozone layer or something by their increased emissions. I'll be long dead before that happens, so take them off and adjust to your heart's content.
I've been called an "Idle Creep" before, and it doesn't bother me much.
As the engine warms and runs better, yes, the idle will creep upward.
Idle creep could be vacuum leak related, but also, as egsols pointed out, be related to a bad carb synch.