Topic: 77 Cb550f idle issues! Please help!!!

[kendrick_the2nd]

My 77cb550f does not seem to idle right. It starts right up and idles smoothe for a few minutes until I blip the throttle or it just dies out. If I blip the throttle it stays at a high rpm, eventually comes down and then struggles to stay on. Another interesting problem is that I have the air mixture screw turned out 7 turns. Yes 7 turns out. I read that it should be somewhere around 2 1/2 or 3 turns out but when I have it there the idle is EXTREMELY high.

As far as my setup goes:
-4 to 1 exhaust
-Uni pods
-Semi vacuum  synced carbs. I say semi because every time I fiddle with the screws the needle doesn't.            move, or the fiddling causes the idle to go very height or very low. I have them synced pretty close but not perfect
- brand new dyna coils, dyna spark plug wires, and dyna ignition
-new plugs
- new jets and clean carbs
- main jet is a 105 and pilot is a 38
- the timing has been set but I need to recheck it to make sure it's good

I have not checked valve clearances or insulator boots for cracks but can these be the cause of my problems? I am also going to check the throttle cable to make sure it is not to tight.

I think it might be a carb issue but This is my first experience working with carbs, so I am unsure. I am at about 5500 ft elevation so could I need different jets?

Any advice will be greatly appreciated. Thanks for your time!

[Jimray23]

If your air screws have to be out that far, you need bigger jets. But first have you done the clear tube test on your floats?

--------------------------------------------------
Jim
1979 kz1000b ltd
    stage 3 cams
    pod air filters
    4-1 open exhaust(no muffler)
    full rewire
    dyna-s ignition
    dyna 3 ohm coils

[BomberMann650]

Yea, you have a lean condition.
Make sure your valve tappets and ignition timing are to spec.  Advancer mechanism needs to be moving freely too.
Replace intake manifold orings if you haven't already. (get a dozen they also fit the tappet inspection covers)
Inspect rubber carb insulators and their clamps.  Replace them if they are cracking at all.
Uni pods are good, but might be contributing to the lean condition.  Turn the ims
screw all the way in (just finger snug) then back it out 1.5 turns to stock.
Also make sure each path and orifice in the carbs are clean, spotless.
If your idle is still hanging, you might have to get a 40 or 42 pilot jet.
Once its idling, do a perfect sync, follow it up with new plugs and an idle plug chop.

[kendrick_the2nd]

Jimray23, I have not done the float test. Never heard of it actually. Battery just died so I will read up and try that out tomorrow. As far as jets go, a bigger jet would mean higher number right( forgive me I am new still)?

Bombermann, I will try tomorrow to check the valves. The advancer seems to be in good shape. I will inspect intake boots and intake manifold o rings tomorrow as well.

Thanks for the help. I will try to make these adjustments asap.