That is what I am thinking also! I've looked around and my best bet is 20666. Same deck, motor, bag, handles, controls, etc.
Also, each time I shut off the mower and restart it again, it falls in choke mode. I have to lower the throttle and slowly get it back up to speed to not hit choke. What could be the problem?
I will try and see tomorrow if I can find some numbers on the motor.