Another reason it is slow to return to idle...

[B-Man]

I recently raised my handlebars, which necessitated replacing the throttle cables with a longer set.

While I had the carbs loose, I adjusted all of the A/F screws to be 1.75 turns out from the seated position. They were originally set at 2.5 turns out but the plugs say it is running a bit rich.

The engine started easily and ran fine, but when it was revved up, it took several seconds to come back down to idle. I checked and checked for a vacuum leak and there wasn't one. After searching a bit here, I decided to adjust the A/F mixture because that was the only thing that I had changed.

Not wanting to pull the carbs again to adjust the A/F ratio, I bought a MotionPro adjusting tool and backed the A/F screws out .25 turns. The change was immediate - the idle was still a little slow to return, but it did come down much faster than before. I adjusted the A/F screws out another .25 turns and that seems to be the sweet spot for this setup.

I'm sure some of you know this, but I did not see a mention of it in any of the threads I read regarding return to idle issues.

[92xjunker]

It is to a point. Hanging idle is a lean condition so, it could be A/F mixture also. 99% of the time it's a " it was running fine then this started" which points to a dirty pilot circuit