Hey fellow GSers I've got a problem with my idle.its a 1996 gs500e
Just cleaned the carbs, pulled the jets, needle, and emulsion tube, cleaned them all
K&N pods and V&H exhaust
40 pilot 150 main and 2 washers on the needle.

I'm not missing any o-rings and have no external vacuum leaks but with no choke and seemingly at random it revs up to 5k rpm and just sits there, sometimes the choke can bring it down, sometimes it doesn't. Throttle cable and choke cable aren't binding up.

I'm stumped.

Check cable routing.....the revs shouldn't change from handlebar lock to lock.

Maybe a silly question, but have you also tried adjusting the idle screw?

Quote from: beRto on June 14, 2016, 08:06:06 PM
Maybe a silly question, but have you also tried adjusting the idle screw?

Yes, moving the idle screw once it's hit 5k does absolutely nothing.

If the slides do not lift then the intake is being "choked."  Slides can fail to lift if there is a tear in the slide diaphragm, if the tiny little oring is missing from under the top cap, or if the slide is stuck shut.  Another possible cause could be a cracked top cap.

With the airbox off shine a flashlight into the carbs while the engine is running, if the slides are lifting you should be able to see it plainly.  With the choke on the slides should sit at the bottom of the travel, with the choke off they should rise up to maybe halfway up the bore.  If they are not lifting you need to find out if the diaphragm or the oring died or lube and clean the slides.

Quote from: lucas on June 16, 2016, 02:14:35 PM
If the slides do not lift then the intake is being "choked."  Slides can fail to lift if there is a tear in the slide diaphragm, if the tiny little oring is missing from under the top cap, or if the slide is stuck shut.  Another possible cause could be a cracked top cap.

With the airbox off shine a flashlight into the carbs while the engine is running, if the slides are lifting you should be able to see it plainly.  With the choke on the slides should sit at the bottom of the travel, with the choke off they should rise up to maybe halfway up the bore.  If they are not lifting you need to find out if the diaphragm or the oring died or lube and clean the slides.

I'll check the slides out, I absolutely have the cap o-rings, had to order new ones as both were gone when I bought the bike. But the slides do move freely by hand and a quick inspection when I had the carbs apart and didn't find any issues with the diaphragms

Just thought of something, maybe the metal piece that connects the choke lever to the choke needles isn't functioning properly, leaving one or both of the needles open

Did you ever find a solution? I've had this EXACT same issue for 7 weeks now and its driving me nuts. I've torn everything apart and still cant fix it. Please let me know someone!!!

Have you watched your slides to see if they are failing to rise?

The possibilities are - stuck throttle, stuck choke, cables that are tight, air filter/box with a leak, intake vacuum leak, exhaust leak and .... drum roll please ..... lean as Druck EPA mandated jetting, combined with the new gas that is 15% air ...

Cool.
Buddha.

Yes I have, all of the cables aren't bound or stuck, and the slides are fine. Everything appears to be working the way it should, but it has the super high idle speed.

Quote from: johnsokt01 on June 30, 2016, 05:02:34 AM
Everything appears to be working the way it should, but it has the super high idle speed.

Ok, well either something needs to be repaired or your settings are wrong.

Did you check for vacuum leaks?  Do you have some slack in the throttle cable?  (You should)

We can't just tell you what is wrong.  Could be any number of things or a combination of things.  You pretty much have to do a process of elimination to find the fix.

I just had this exact problem, the bike would idle at 5000rpm with no choke and I had a vacuum leak at the intake boots.  I would spray some wd-40 around the intake boots with the bike running to see if your idle changes.  If it does then you've found the problem.

Quote from: jjmaine on June 30, 2016, 11:53:44 AM
snip... If it does then you've found the problem.

You've found -at least one of- the problems 

Im still working on it, just ordered a new 3way valve assembly for it, im very convinced its something electrical because i tore the carbs apart myself and even had a mechanic rebuild it 2 times. If that fails, what should be the next thing i replace? Also once its warmed up, i can start it without the choke and it idles at 1500rpm but backfires a few times, then once i give it a tiny bit throttle it speeds up to 5k and stays their on its own, it doesnt come back down.

I do not believe there are any electrical problems that can raise your idle speed like that.

What is a 3 way valve?

In my opinion there is not a part that you should replace next.  You need to diagnose the problem and replace the parts that you find are not functioning.

Of course you could throw parts at it until it runs right, that'd help the economy out some.

The key to diagnosing a sick engine is to perform tests that will prove whether a part or system is functioning as it should.  It's a process of elimination and is like being a detective.  You need to use your logic and puzzle-solving brain meats.  What have you tested, and what did the results tell you?

Without more information about what you've tried we are kind of in the dark here and you'll really only get standard advice that way.

I've done everything the OP said, and I'm still having this issue. Hence I keep posting on this thread instead of creating my own. I'm with this issue there is really no way to test anything because anything I do has no affect. The carb was rebuilt and tuned and synced 2 times so there is no way to keep testing other than replacing 1 thing at a time.