Something new to report,
I removed the airflow sensor pot. and gently wiped the 2 tracks clean. Now I'm not sure that did anything, but I just reinstalled it without calibrating it and the rpms went up considerably, about 1500rpm idle with motor warm. Also the duty cycle seemed more active.
Tomorrow I will set the airflow pot. buy reading the voltage across pins
1 & 2, value I believe is .75v +/- .10v. May not mean anything but a change never the less.
I guess the airfow sensor is a kinda throttle position sensor.
I'll post the results after fine tuning.

Michael