Craftsman 42" 16hp sat in storage for 3 years. I just got it out and changed the oil, new battery, new spark plug, and new air filter. I filled it with gas and the engine won't turn over. The engine keeps trying but does not start. I can only get it to run when I spray :"fast start" into the carburetor.

I have not replaced the fuel filter and am using Regular gas (my neighbor recommended to siphon the gas and replace with Premium).

What do you think?

You don't need premium.. Did you park it with fuel in the tank and in the carb? If so the carb needs taken apart and cleaned. Enough gum may have formed to stick the needle valve closed and prevent fuel from entering the float bowl.

Thanks. There was no fuel in the tank, but definitely in the carb and fuel lines. I will take apart to clean and let you know.

I took apart the carb and cleaned it. The float bowl was flooded so I emptied and cleaned as well. I also replace the fuel lines and filter. Still the engine does not start. The engine spins, but only turns over when I spray Fast Start into the air filter.

I noticed the belt underneath is a bit loose, not tight. Could that something to do with it? Maybe it is not tight enough to give the engine enough spin?

Please help! I am about to make the costly mistake of hiring a lawn mowing company :(

The belt doesn't turn the engine.
Is there a thing on the bottm of the carb that has wires going to it ?
If so this is a fuel shut off solenoid , make sure the needle is working in and out on this.
Luck