I'm not sure why my bike idles higher after it warms up, HELP!

[steve_crabb]

I have a 1981 gs550 i have recently taken the carbs off and had them set to factory specs and given them a really good cleaning. i also replaced all the boots and the o-rings and put a new air filter in the bike as well (an oem replacement) My bikes idle is emotional!!!! it will start with a little choke and run at about 1000 rpms then when i take it on the road and warm it up it idles all the way up to 2000 rpms and stays there. i have adjusted the knob between carbs 2 and 3 and it still runs high, i'm at a complete loss where to go from here! any advice would be a great help! thanks.

[nabrams]

9 times out of 10 the problem you describe is an air leak (or exhaust leak) of some sort. It is the kind of leak that is small enough to only have an effect once the bike wams up - been there, done that. There's a million posts on how to search/fix air/exhaust leaks - do a search for the sage advice.

[Jethro]

When you did the boots, did you use new clamps as well? I've had issues with old clamps doing weird things. Also, some folks use standard hose clamps, but I've had issues with them. If you notice, the stock clamps have a piece under the adjuster to ensure the boots don't bunch up under the adjuster.

Did you vaccum synch the carbs after the cleaning? What does the bike do when it's warmed up and you apply the choke?

[steve_crabb]

i did use the old clamps but they looked ok, i did not have the carbs vac synced though, do you think that could be the problem?

[crc1214]

Don't give up on the idle screw just yet. Fiddle with it when the bike is nice and warm and at 2000 RPMs. If there was an air leak the idle would just steadily keep increasing. The carb synch is probably a very good idea as well.

[tconroy]

I have a 1981 gs550 i have recently taken the carbs off and had them set to factory specs and given them a really good cleaning. i also replaced all the boots and the o-rings and put a new air filter in the bike as well (an oem replacement) My bikes idle is emotional!!!! it will start with a little choke and run at about 1000 rpms then when i take it on the road and warm it up it idles all the way up to 2000 rpms and stays there. i have adjusted the knob between carbs 2 and 3 and it still runs high, i'm at a complete loss where to go from here! any advice would be a great help! thanks.

replace your o-rings and intake boots if they look cracked or seperated.High idle problems are caused from the carbs to the engine. Even though your boots may look good they probably aren't.Spray wd-40 around them to see if the idle changes and also check your clamps.My bike did the same thing till i replaced the o-rings and boots.Also check you throttle cable adjustment.

[KEITH KRAUSE]

Intake leak almost certainly. You can't vacuum synch until the leak is repaired.