when releasing throttle rpms stay up for a couple of seconds

[#1 SCOOTER TRASH]

I just modified my stock cv carb on a 99 softail. I rejeted slow jet to a #45 from a #42. Went from a #180 to a #190 on the main. Put a 1/16" washer under the needle. Drilled vaccume port to 1/8". I shortened spring 4 rounds. I turned idle mixture screw to 2 3/4 turns out. The bike runs awesome.......BUT when I turn throttle and release it stays open for a second or two before going back to idle. It does the same thing between gears (like a surge or its hanging up?). I've checked cables and their not binding. Any ideas?    Thanks in advance.

[joesfxr]

take the air cleaner off and see if the slid is hanging up

[Julio]

That's a symptom of the idle mixture being too lean.

[#1 SCOOTER TRASH]

Thx a bunch. Sounds like an easy fix. I will check it out.

[Grayrider]

Is it the actual throttle not returning or just the revs staying up?
Why did you shorten the spring? Is it now too weak to return to idle?
Did you try adjusting the cables with minimum slack?
Did you pull the carb or just the bowl?

[Bruno-Katz Fokkerpilot]

Is it the actual throttle not returning or just the revs staying up?
Why did you shorten the spring? Is it now too weak to return to idle?
Did you try adjusting the cables with minimum slack?
Did you pull the carb or just the bowl?

I had this problem, it plagued me for two years. I have a Mikuni 42 but same principle. All that was wrong was, i`d not left enough slack in the throttle cable. I`m not suggesting you`re as stupid as me, but, before you dive in and start stripping things down, just take a look at simple first.

[Lew]

A too tight idle cable is usually the cause for this.

[mkd]

to adjust the throttle cable (the outer cable first)loosen the ferrule adjustment jam nuts and shorten both cables up some.open the throttle and check to see if the butterfly is wide open as far as it will go.if not you want to lenghten the outer cable till max throttle is obtained and no more then tighten ferrule.on the idle cable (inner cable) rotate the handlebars to the full right position and turn the grip to max throttle position and release.throttle grip should return to idle position.if it does not the idle cable is too tight.you want to tighten the idle cable a little at a time and check to make sure the throttle returns.you have the idle cable adjusted correctly when the front end is turned to full right and you have taken the slack out of the idle cable and the throttle still returns all the way  to the idle position without binding.it should snap briskly back to idle with the idle cable loose and as you adjust the idle cable tighter it will noticeably affect the speed it snaps back.if the idle cable is way too tight it will not go back to idle at all or hang like you are experiencing.once you have it adjusted at full turn right you can check it at center and full turn left.the cables have the biggest binding at full turn right and should have less bind at center and left positions.