Gas stove sometimes has sparks, but they do not light the fire, what is the reason?

      If want to light a fire, there are three points: 1.the suitable strength of the spark,2. the suitable position of the spark in the fire cover air hole, 3.the appropriate mixed concentration of the ejected gas and air. As long as these three points are satisfied, we will certainly be able to light a fire. So from the following inspection: check whether the gas out, can use a lighter light fire, or hear / smell the smell, if there is no gas out, check whether the intake valve open; turn the ignition needle, make the spark just hit the edge of the nearest hole; adjust the valve, because the valve is too big, gas and air mixing ratio is too small, not easy to light fire. Keep the gas concentration high; adjust the windshield to the blue flame, but at the bottom of the flame.