All the on/off and low oil sensor wiring does is stop the spark so if you have spark then that isn't the problem. If you're running gas with ethanol in it likely the emulsion tube and/or jets are clogged or rusty. Ethanol attracts water so if it was sitting around for that long you'll need to pull the jets and e-tube and take a look. Other than that someone else will need to chime in, good luck!