There is a screw on the portside of the motor which controls the idle. You firstly have to make sure that your cable puls the throttle all the way back. If this does not happen you have to adjust your cables. Another problem can be that the roller of the carb hits the cam to soon. This also increases the idle rpm. On the cam, two notches are present. The roller should start to touch the cam between these notches. If it touches to soon, the idle will also increase.
If you have any questions. just ask.
