Throttle idle problem

I have just re-assembled my bike after a tear down. I can not get the throttle to work properly, After engaging the clutch it begins to accelerate on its own without use of the throttle. with choke open it idles perfect as I close the choke it raps out the motor to extreme rpms! what have I messed up uin the re-assemble? any suggestions?

would not having a muffler hooked up cause any of this issue? I did cut off the exhaust a few inches back from the flange so I could mock up the new pipe I am making.

The exhaust removal was the cause!??! I put the exhaust on and was back to running great. Got some minor tweaking to do to get the idle worked out but I am back on the road!