I think this problem has been discussed before.  Sometimes my GS decides it wants to idle at 3500 rpm.  It was a seldom occurrence, but it's becoming more frequent.  Usually it will idle at 3500 for ~30 seconds and then settle down to 1200.  Now it's intermittently getting stuck at 3500 on idle.  It did it to me yesterday in a traffic jam; I was worried he engine would overheat.  What's going on here?  Do I have a sticky throttle cable or something?   

Quote from: Toad Rider on October 29, 2007, 07:13:28 AM
I think this problem has been discussed before.  Sometimes my GS decides it wants to idle at 3500 rpm.  It was a seldom occurrence, but it's becoming more frequent.  Usually it will idle at 3500 for ~30 seconds and then settle down to 1200.  Now it's intermittently getting stuck at 3500 on idle.  It did it to me yesterday in a traffic jam; I was worried he engine would overheat.  What's going on here?  Do I have a sticky throttle cable or something?   

EXACT same problem, still searching for the cure.

For a temp solution, don't hang in neutral at a stop or light, go straight into first (recommended by MSF anyways). I found that if the idle jumps upwards, releasing the clutch so it momentarily catches will bring the idle back down. If you are in neutral and the idle jumps, its a real grinding Buddha Loves You to try to get the trans back in gear.

I'm currently doing thread searches, haven't seen anything yet, but I need to do a more thorough search.

Also, engine won't overheat, don't worry. Cruising RPMs are between 3k-5k, and from what I've heard the torque curve tops maxes at 9k.

Easy way to rule out the sticking throttle is to just push it forward so as to close the throttle manually. If that isn't the issue, try adjusting the idle screw, its a knob in between the carbs. Just do a search for the idle adjustment knob it should find a thread with picutres for reference. Thats where I would start.

Nah, it's not the idle screw; more often then not the bike does idle at 1200. It's after some riding, that the idle either sticks or jumps up to 3k+. Once you get the idle back down, though, it usually stays.

I had the same problem and it was the idle screw. The problem is that if it's set to 1200 rpm when the bike isn't fully warmed, it tends to behave erratically when it is warm (i.e. spontaneously jumping to 3000 rpm etc.)

Hmm, I'll definitely double check to be sure. If it is I'm going to feel like a real moron. 

If not! This thread might have some answers!

http://gstwins.com/gsboard/index.php?topic=18444.0

I'll make the progression from easiest to toughest, let you know how it goes after the weekend

-double-check idle screw
-lube throttle cable
-sea-foam gas treatment

if none of this works, gets more complicated, look into:

-thorough carb cleaning
-possible leaking allowing additional incoming air

had the same issue. Just make sure you adjust the idle screw when the engine is FULLY warmed up.
Give it a good spin and then adjust the screw. It helped in my case. Hope it helps in yours.
Cheers

I had a similar problem when I first bought my bike.  Although mine would sometimes die completely as well as idle high.  It turned out that my choke cable had been damaged.  I think the choke mechanism was floating around and causing differening air/fuel conditions.  I haven't had a problem since replacing the choke cable.

Ride the bike around the block a few times until it is warm, then stop somewhere safe.  Let the bike idle in neutral and turn the bars from left lock to right lock.  Does it rev?

Yes. Mine revs at right lock.  What do I do?

Mine has this exact problem. It randomly idles at 3500 and also revs at full lock right. (Or for that matter, a little bit right.) I took it on a long ride and then adjusted the idle mix, seemed to work, but not all the time. I just installed new 89 clip-ons. They caused a whole bunch more problems, once my new clutch and throttle cable come in, maybe it'll stop. <-But I have a week to wait before they get here. Keep us posted!

Quote from: Toad Rider on October 29, 2007, 11:29:01 AM
Yes. Mine revs at right lock.  What do I do?

Don't turn the bars to right lock.

Check your cable routing.  Either the throttle or choke cable is getting pulled when you turn the bars.  I'd guess the choke.

Quote from: Toad Rider on October 29, 2007, 11:29:01 AM
Yes. Mine revs at right lock.  What do I do?

Quote from: DrtRydr23 on October 29, 2007, 12:44:44 PMCheck your cable routing.  Either the throttle or choke cable is getting pulled when you turn the bars.  I'd guess the choke.

Over time I have re-routed both of my cables to bypass the forks altogether ... the throttle cable because of this lock-left, lock-right problem, and the choke cable because I was too lazy to route the replacement cable correctly. 

Quote from: Kerry on October 29, 2007, 01:00:06 PM

Quote from: Toad Rider on October 29, 2007, 11:29:01 AM
Yes. Mine revs at right lock.  What do I do?

Quote from: DrtRydr23 on October 29, 2007, 12:44:44 PMCheck your cable routing.  Either the throttle or choke cable is getting pulled when you turn the bars.  I'd guess the choke.

Over time I have re-routed both of my cables to bypass the forks altogether ... the throttle cable because of this lock-left, lock-right problem, and the choke cable because I was too lazy to route the replacement cable correctly. 

I'd guess that you wouldn't have much choice bu to reroute both cables with the bar risers and all.

Quote from: DrtRydr23 on October 29, 2007, 01:44:14 PM
I'd guess that you wouldn't have much choice bu to reroute both cables with the bar risers and all.

You're right - that must have been why I rerouted the throttle cable.  I believe the original clutch cable went out before I got the risers.

Ahah!  Revving with the bars turned is generally one of two things:

1)  Improper cable routing

2)  Not enough slack in the throttle cable

With the bars straight, check the throttle cable slack.  The periphery of the throttle should move about 3/16" before you feel the cable tighten.  If the adjustment is much less, pull the tank up and adjust the little nut on the end of the throttle cable towards the carbs (clockwise from the top) until you get the necessary slack.

Kerry has routing covered. 

Air leak?

Quote from: Toad Rider on October 29, 2007, 11:29:01 AM
Yes. Mine revs at right lock.  What do I do?

Adjust the throttle cable play at the right carb.  It's a pain, but that will solve your problem.

Woooo can't wait to see if that's my problem as well! Thanks for the help!