Posted on April 20, 2013 by admin Just how difficult is flame adjustment on the PF13L series? Hit/Miss or impossible, of requires a steady hand. PF13L series flame adjustment is continuous. You use the knob on top of the red regulator for the adjustment. Post navigationPrevious post: I am not clear on what you mean by “stove ring diameter” on all your stoves.Next post: What is the difference between the PF13CS130 and the PF13S130?