Idling high after warm up

[AC Rider]

Anyone...what do I need to do to get my bike to stop idling high after warming up?  After riding for about 5 minutes, my bike will idle up to around 4K when I come to a stop.  This is very annoying when you are stuck at a red light for awhile!  I run my bike with a smidge of choke while riding if that helps any with the diagnosis.


1981 CB750K
"Freedom on 2 wheels"

[vern401]

why with the choke?
It is by itself enough to make it idle high.
the 81 750k? or is it a different bike?

[AC Rider]

The bike was still running a little rough from sitting up for a few months.  I have been riding the bike gradually lessening the choke until recently when I have not been using it, but the bike still revs up to 4K after warm up.  I have tried adjusting the idle screw, but it has not affected this issue any.  What's next on the checklist?

[vern401]

Ok now I understand a little better. On thing you can do is to do a carb cleaning.
A good way to do it is to take the floats and CV pistons out. Set the floats and float valves in order.
I'll post our link here for carb cleaning..
If you have an ultrasonic use it. If not you can make one with a container big enough to hold the carb rack and fluid that will be over the carbs. A small hand sander works well to vibrate the tank and fluid. I use Pine-Sol for the cleaning solution. It also makes my shop smell great.
http://honda-cb750-s.456789.n3.nabble.com/DOHC-carb-cleaning-procedure-td867809.html#a867809
Let the carbs sit in the cleaning solution (Pine-Sol) for a few hours then blow out the ports with compressed air. resoak with agitation. I do this a few times or until they are nice and clean.
Reasemble check the float height set the pilots. Warm the bike up and with no choke on check the vacuume sync of the carbs. This should be ok and not need adjustin as long as you do not mess with the adjusting screws between the carbs.
I'll build an ultrasonic like I discribed above and get some pics of it for the site.