Did you have a multimeter with a duty cycle function connected to the proper pins of the test socket? You should only adjust the mixture screw if the duty cycle is not in the proper range. My recommendation is to shoot for 45-50 percent at idle. If the engine does not cold start, cold idle, and hot idle properly at 45-50 percent duty cycle, there is something else wrong. It's not the basic mixture setting.

The proper procedure is at:

www.landiss.com/mixture.htm

Duke