On Coleman 424 dual liquid fuel stoves, the generator vaporises the fuel during the ignition process. Over time, this vaporisation can lead to carbon accumulation inside the generator and eventually cause a generator blockage. When a blockage occurs, the stove will light for a few seconds only or not at all and you won't hear air passing through when you open the valve. If this happens, cleaning the generator may fix the issue. Coleman has designed the 424 stove with a needle assembly to dislodge the carbon.
Turn the valve knob clockwise as much as possible to close the valve and push the needle assembly into the generator.
Reopen the valve and try to light the stove as you would normally for your stove type. If you have a 424 electronic ignition stove, turn the valve knob counterclockwise two full turns at the same time that you turn the ignition knob. If you have a 424 standard ignition stove, light a match and hold it near the main burner, and then turn the valve knob counterclockwise quickly two full turns.
Close the valve again if your stove didn't light after cleaning the generator. Contact Coleman customer service or an authorised Coleman dealer for assistance with procuring and installing a replacement generator.