r.p.m. is very high when first fired up

[GOOD VIBRATIONS 1981]

hello all, when ever i fire up my motor and its cold the R.P.M.'s are pretty high sounding and then while it is warming up it gets higher and lower back and forth until I put it in gear and take off. And the engine is not all the way broke in yet eighter. my carb is tuned right also. anyone know why the motor is doing this? It is a 66cc 2stroke china motor kit. BOYGOFAST. tHANKS

 

[motorpsycho]

It could be one of 3 things.
#1. your idle screw is turned all the way in.
#2. you installed the throttle slide wrong.
#3. you have a major air leak at the intake tube.