Small Engine Troubleshooting Problems? Ask a Mechanic Now.
Welcome to JUST ANSWER small engines, let me try to help you !! I don't know it all, but maybe together we can get you a satisfactory answer!
Remove spark plugs and put teaspoon of fuel direct into the spark plug holes, re-install spark plugs and see if the engine will start for a few seconds. If it does, the carburetor will need a through cleaning or replacement. Oil pressure switch will kill engine only after it starts,
Has to be at carburetor. Is the fuel solenoid working , (clicking)if you flip switch on and off?
Is there a solenoid in the carburetor?
If not, carburetor has to be problem, replace it.
It has to open the main jet as soon as the switch is tuned on, does it click open?
Needs 12 volts, but if it does not open, main jet is closed. You can bench test it.
!! Getting there! New carburetor is the likey answer, but new fuel and fuel treatment might be enough to keep it running!