I have a 2000 440ex with 38mm carb. I got all kinds of problems with the throttle sticking. It stick right before where the idle is set when you let off the throttle. That is the only place it sticks. The calbe is good so its in the accelerator pump or the slide return spring needing to be adjusted to make it spring back a little harder. But don't know how to adjust the spring or if it can be adjust.

 

Give their tech service a call.