Check out this thread on sksboards, and try the "paper clip fix". If this works for you, then you can be confident that the valve is the problem. I would suggest investigating the "ball bearing fix" or buying a new gas valve from Murray's Gunsmithing or CNC Warrior.
Just to be sure... the on position for the valve is the 2 O'clock, and off is 12 O'clock.
Just to be sure... the on position for the valve is the 2 O'clock, and off is 12 O'clock.