How to adjust the idle?

[Motorcycleguyr1]

I bought a rc390 used and the idle has been bumped way up. It idles at 3500 RPM when warmed up. When cold it varrys between 2 and 3K RPM. Does anyone know how to adjust it?

 

[shreeshar7]

I bought a rc390 used and the idle has been bumped way up. It idles at 3500 RPM when warmed up. When cold it varrys between 2 and 3K RPM. Does anyone know how to adjust it?

This is something not normal, something is wrong somewhere with the sensors. Check throttle position sensor on the throttle body.

 

[Motorcycleguyr1]

This is something not normal, something is wrong somewhere with the sensors. Check throttle position sensor on the throttle body.

I am not sure how to do that.. the guy I bought it from is very knowledgeable. He told me he bumped the idol. He used it for a track only setup. I'm just having trouble reaching him to find out how to lower it..

 

[shreeshar7]

I am not sure how to do that.. the guy I bought it from is very knowledgeable. He told me he bumped the idol. He used it for a track only setup. I'm just having trouble reaching him to find out how to lower it..

Well,I would not believe if someone bs Me like that, even if he set the idle..it shouldn't vary at different temps.
If it was all that simple, why didn't he do it before selling it to you?
High idle for track use..? Really?
Many things crossing my mind.


Anyways, you can find a alen bolt on the left side of the bike on the throttle body,maybe a size 3 alen key would do,turn it counter clockwise to reduce idle rpm.
Note: you are not actually setting idle rpm.but instead you're varying throttle position to get desired results.

 

[shreeshar7]

Here, find this screw to the left side of the bike