I have been working on various things on my forklift for a year. Two weeks ago I was almost there. Using starter fluid I got my forklift started and running. Need to put transmission oil in because it would barely move when I put in gear. I probably ran the engine for about 10 minutes. Ran good. Two weeks later, I buy the oil, and get ready to start the forklift, but it won't start. Using starting fluid iT does cough 3 or 4 times, then NOTHING. I keep trying fluid, no cough, just spins and spins. So I re check my spark with my spark detection light. I check it at the coil, and I check it at the plug. Good solid spark both times. So I decide that maybe the carburetor got plugged with rancid gas, (Even though if this were the case starter fluid should still make it COUGH) So I rebuild the carburetor. Check that the fuel pump is pumping gas from the tank, which it is. Put the Carburetor back on (It was dirty with rust, but I did not find any plugged jets) NOTHING. Engine just cranks and cranks, never fires. I tried more starter fluid. Nothing. I'm stumped. ANYBODY got any suggestions. I checked the engine oil, its fine. How can I be getting fuel and air and spark and the engine does not try and start????? Does not even cough, choked, or un choked, pumping the pedal, or no pedal. HELP