Topic: 78 CB550K RPM return problem

[bhh1989]

I am so very close to finishing this bike, this is the final kink to work out. After I get the bike warmed up, it will idle great all the way down to 1K rpms and it rides very well. Problem is is that it seems to be slow to return to idle rpms sometimes, it will remain around 2 or 3k to where I have to drop the idle screw til it stops, then bring it back up again before it dies. I have already synced the carbs and it has no air leaks that I could find by spraying starting fluid in all the joints, just can't get this problem solved. I have read about advancers sticking, could that be it? Where is it for me to check it? Only other thing about the bike is that the airbox top is just sitting on it because I cannot find the special little tabs that it needs to tighten it down.

carpy 4 into 1
PD46C carbs
Stock airbox with UNI

[flybox1]

the advancer mechanism is easily removed, cleaned, and lubed.  it should be done as part of maintenance anyway.
what jetting do you have in your carbs?
timing and advance spot on?
what color are your plugs after a long idle?
return spring strong enough to snap the throttle closed when you let go?
both push/pull cables lubed and move smoothly?

[Bankerdanny]

The PD46 is a mechanical slide, not a vacuum slide like a CV carb. If playing with the idle stop makes a difference then I would say that you have sticking slides. You have a 2 cable system where one opens the slides and the other closes them. Check the tensions cables and make sure that they allow the slides to fully close.