Intake boots on a 80 GS1100E

[gadang]

Hey,
I just got my new bike and am having a few issues. First the idle is kinda crazy when it warms up...like an air leak or something along those lines. I replaced the petcock because it had some goofy bypass going on since the other one was bad and lubed the throttle cable. I used to have a 82 GS650G and replaced the boots on it but they are way different then the ones on the "E".

What I need to know is first are the boots on the 1100 supposed to look kinda "balloon" like between the clamps? Are supposed to see them (breath) when the motor is running? They are soft but I am not sure what I am looking at with this motor. I really think this is an air problem....or maybe it is running too lean?

Any help would be great!

Thanks!

[chef1366]

Yes they do pulse when running.
Spray a some carb cleaner of WD-40 around the boots when running and see if the idle dives.

[gadang]

I did try that and the idle seemed to climb not drop. Could that be a lean issue?

[tfb]

Another source of air leak is the vacuum line to the fuel tap.

And yes, the bike could be running to lean at idle.

But to check this, wait until the engine is thoroughly warmed up. Then 'blip' the throttle. If idle mixture is too lean, the revs will hang at higher rpm for a moment before they finally come down to idle speed. If idle mixture is too rich, the revs will dip below idle speed, before returning. If the revs drop straight back to idle speed, then idle mixture is set correctly.

Also, is your valve timing correct? Having the timing a couple of teeth out will cause ropey idling behaviour.

[bwringer]

You do have the airbox installed, right?

[gadang]

Tfb. When I was spraying I did it right on the vacuum inlet and it did speed up. I did cut back on the hose and replaced it but did not get a chance to check it after that.
Also the throttle does like you stated for a "lean" scenario..I rev it and it hangs at a higher rpm before dropping back down...and if I run for awhile and come to a light the idle stays higher and then falls.

Yes bwringer I do have the air box installed...since I hear that the 1100E doesn't like to run any other way.

This bike does have a header on it but stock box.

Thanks guys!

[chef1366]

If the idle changes with the spray then you have a leak. This is as long as the spray isn't getting into the carbs through the airbox.

[gadang]

I hope by cutting back the hose that fixed that issue since I sprayed on the other boots and it did not change...only when I sprayed on the inlet tube. I stayed on the motor side of the carbs when spraying.

I would like to go the mixture route but am not sure where the correct screw is for adjustment. The bike runs really good off of idle and has good power all the way up. The header is not overly discolored but a little.