fhpe77 is entirely correct.
However, if we give drbrak the benefit of the doubt that he installed the other necessities as part of his project, I'd say the following in response to the CT200u trying to drive at idle...
The clutch is only able to engage at a certain rpm. Seems this rpm is being reached at the lowest throttle setting (idle). That tells me you either need to adjust your idle down at the carburetor, or your throttle cable is adjusted incorrectly (threaded too far out of the throttle control) and is holding the throttle open slightly.