Kz550 High Idle after reassembly

I recently took my 1984 kz550 down to bare frame and cleaned it up, change the head and valve gaskets. In the last few days I have gotten it back together and have been trying to get it running. Figuring out the vacuum system took a while but I finally got it hooked up correctly i think. The bike fires every time now but it is idleing at 4k. I tried adjusting it with the idle knob but can only get it to go higher, not any lower than 4k. I was hoping to be able to ride it tomorrow so any help would be appreciated. Thanks in advance. I did search but couldn't find the answer i need.

You must have a LARGE vacuum leak in most likely all four carbs. IE you do not have the vacuum lines hooked up right.

If it seems to run normal, (no popping or erratice revving), it may also just be the throttle cable is hanging up. Make sure all of the junctions in the cable housing are fully seated. Also make sure there is some slack in the cable (and freeplay on the throttle) when the throttle is closed.

With all the work you did, soemthing may have happened to the cable.

So sorry to pull up a very old and dead thread, but I am wondering if you ever did find a solution?

I am a new KZ550 owner that had a great running bike....Until I filled the fuel tank. Now it does exactly a yours did and idles @ approx. 4K RPM.

I have looked at the idle knob, all the boots, etc. The only thing I could figure is there is a problem with the vacuum diaphragm as it was running great on reserve with a little bit of fuel in the tank.

Thanks