Vacuum problem...?

[Bunbun]

Hey all, long time motorcyclist, GS noob here.  I've been lurking for a couple weeks, searching and reading about the GS and I have to give Kudos to gsjack for the tire research

Anyway, I have a question I haven't found an answer to.  I hooked up my carb-sych tool and at idle, the mercury doesn't really even move.  I cranked it up to about 5k and slowly let off -- almost no movement.  I decided to do the unthinkable and tac it up then chop the throttle.... the mercury moved about halfway up the tubes.  After this I took off the tube from the tool to see if I could feel the vacuum.  I could, but very faintly, almost imperceptible.  

The bike sat for about a year but was started occasionally.  When I went to pick it up, I rode it around a bit and it ran like crap.  I just finished a complete maintenance and all I have left to do is synch the carbs and play with the mixture a bit.  On the valve check, they were all actually a bit tight, which I've never seen happen before.  The bike is an 02 and has 6k miles on it.  

Symptoms:  Takes a couple mins on choke to run.  Throttle response is terrible, however after warm up, I can slowly open the throttle and get it up into the high RPM range.  It does miss a bit as well.

Plugs, oil, and all that good stuff have been replaced and specced as per the manual.  

Any hints and ideas would be greatly appreciated.  My friend really wants her bike to run--  help me!  

Bun

[scratch]

Welcome!

You have a leak somewhere. Most likely the o-rings under the caps are missing, by the description of the lack of movement on your carb sticks. The o-rings, that are potentially missing, seal the base of the vacuum spigot under the cap, and would also allow air to be drawn past into the carb downstream of the slide, thus leaning out your mixture.

The long warm-up is normal of a stock jetted (read: lean) bike, unless the carbs aren't seated properly.

[xtalman]

I'm not an expert, but here are some problems I ran into when I got my bike.

Re: vacuum

Is the vacuum hose from the left carb hooked up to the frame-mounted fuel petcock?  Does the bike run with the petcock in the ON position, or is it in PRIME?

Also, both carbs have a little port on the right hand side.  The left carb port hooks up to the frame mounted fuel petcock, but the right carb port should be plugged/closed.  

Have you cleaned the carbs and checked the condition of the rubber gaskets/o-rings?

Also, I found it a hassle to get the airbox hooked back up to the carbs.  There might be a leak there too.

Has the bike been rejetted?  Usually the mixture screws are covered with brass plugs if it's stock.

[Bunbun]

Finally got some time to play with it.  One thing I completely forgot to do, and I'm ashamed to say, was a good full clean of the carbs.  Unfortunately I took the POs word that it'd been started on a fairly regular basis.  Well, I stripped off the carbs and ripped 'em apart.  I don't think I've ever seen such nasty carbs in my life.  Jets were overgrown with green crap, float bowl screws were rusty and the bowls were completely covered in fuzzy green stuff.  

To top it off, some of the o-rings were hard and nappy.  Whether this was the problem or not, I'll find out in a few days.  Hopefully so... I don't wanna mess around with it anymore  A nice 30 minute dip and they are nice and shiny... now I just gotta go grab some o-rings and gaskets... I hope the local shop has some in stock.

Thanks for the ideas -- BTW, one of the o-rings WAS in fact missing from under the cap.

Bun