Question on HBO 2 generation (temporarily)

People in my HBO 2 is a solenoid valve on the gas filter it connects 2 wires plus and minus respectively if by mistake the wires are reversed, well let's say for a while and went well with them but only on gasoline could I ushatat if this valve mixed up wires? How to check if it works? The question is if the gearbox does not respond to the sensitivity of the screw that is at completely twisted the screw machine is not deaf but still works where to look? Can it be to blame solenoid valve ?! If the new repair kit has recently changed on the gear