Small Engine Troubleshooting Problems? Ask a Mechanic Now.
Welcome to JUST ANSWER small engines, let me try to help you !! I don't know it all, but maybe together we can get you a satisfactory answer!
Knob under the seat has to be turned out CCW to loosen. If it is out already, it should work, if screwed in all the way, then it has to be loosened. have you used a big pair of pliers to loosen?
I see question is still open, did you see my response?