Hi Byomarimba, I have a 3043YW with exactly same problem...... My motor is new new..... Just thinking how it happened. The bump head knob in left hand thread, as I have discovered........ I think I'm right. I can't get if off yet. And I think someone has tried to undo it in wrong direction buggering the thing inside....... I will take it apart and try to make another fitting and squeese it in the shaft.....
Or put the motor on my pushbike...... somehow :-) cheers speedy
........................Keep your blades sharp......................
