Topic: 77 CB550K Carb question (see picture)

[vintagemcycleguy]

The carbs on this 77 CB550 are driving me nuts. Idle is high and will not settle down unless I turn the throttle backwards. If I let go of the throttle the idle stays high. Look at the attached picture, is there suppose to be a spring attached to that protrusion sticking out with the groove from the throttle linkage assembly. It seem like there is something missing. Any help is appreciated

[ieism]

That looks alright to me. I think mine looks the same, but i'm not 100% sure. I think there should be a separate spring somewhere behind the idlescrew/stop. I'm pretty sure that's the one I spot in the top of your picture.
I would disconnect both trottlecables, make sure they are routed correct with no kinks or sharp bends. Then lube them well and reinstall. Maybe it's just a sticky cable.
When you dissconect the cables, pull the trottle link by hand and see if it springs back, that should give you a clue...

[edbikerii]

Let me tell you, I think it is kind of strange, as I have exactly the same bike as you, a 1977 CB550K, but on my bike there is no protroducing bar from the throttle wheel as in your photo.  I think that is what you are asking about, correct?  The brass rod that extends from the side of the throttle wheel and has a groove on the end of it?

Well, neither the bank of carbs on my bike, nor my two spare banks of carbs has that rod.

So, my guess is that no, you are not supposed to have a spring attached to it, and that all is ok there.

Based on your description, however, I think your throttle pull cable is adjusted too tight.  Before adjusting it, try disconnecting it, and see if the throttle closes completely.  If it does, then you know what you have to do.

[Dave L]

HI
My honda 550f2 1979  has a spring  on this point which keeps the linkage under tension , however as i understand it the carbs do differ from mine to a k .
Whati do know si that the symptoms you have point very much to the sloe idle jets being blocked or the floats and the valves need looking at.
My money would be on the idle jets ,
 or the air screw setting you need to read up on this as it differs from model to model
Dave

[bwaller]

Like edbikerii says that throttle cam isn't the same as the one on a set of PD's off the 77 I have. Regardless just make sure you have some free play in your cable and that the throttle snaps shut with the spring you have.

I assume you've had these apart, probably a carb sync is in order.

[Jonesy]

How's your choke cable adjustment? The cable operates a fast-idle cam that keeps the bike running faster when starting the bike, so you don't have to crack the throttle by hand and hold it while warming up the bike. It is supposed to back off completely then the choke knob is pressed all the way in. Twisting the throttle backwards will override it. If the cable is OK, your fast-idle cam may need adjustment.

[csendker]

a good bet is to look on the carb body/manifold flange (motor side) to find the carb setup number punched there.  That will at least tell you what you have, and if it's the right set-up for your year.  I attached a pic with the number circled for mine.  You can't read the number in the pic, but you can see where to look.  Otherwise, I also attached the exploded diagram for the '77 carbs.