Jenn Aire stove gas controls sticky

Oven/Range/Cooktop Repair
1

Our stove is dual fuel – gas burners, electric oven. The left side burner controls for the griddle (which we rarely use) do not seem to regulate the gas properly, they only operate on high and cannot be turned down. The right side controls which we use all the time regulate the burners from high to low.

Is this from lack of use since we so seldom use the griddle?
Is there some way to lubricate them?
If we use them more will they free up or should they be replaced?

2

Turn on the burner. Turn it to low. Remove the knob (just pull it off). Using a small bladed screwdriver, insert it down the shaft of the control. Turn the adjustment screw till the low burner setting has an acceptable flame. There is no high adjustment.