Try removing the spark plug and put a thimble of fuel direct into the spark plug hole, reinstall spark plug and see if it will fire. Be sure the on/off switch in in the on position.
with spark plug removed and grounded do you have spark?
Why a negative rating?
If you didn't try to start unit with oil in the gas , there should be no oil in the fuel system, so it appears you have no spark, so the switch may not be on, or wire is off.
Spark plug clean? And it did not start with fuel in the cylinder?
It has no primer bulb, just the choke, to aid in starting, and shows to have decompression valve that is pushed in for easier starting. ??
I have a 455 and it has to be choked until it starts, then choke is pushed in. Sounds like it wants to run, just don't have the right combination. Too much fuel, or too little fuel! ???
Do you have a vacuum pump where you can remove the return fuel line at the carburetor, and suck fuel through the carburetor? That would clear any oil in the fuel line and carburetor??
Remove line at the carburetor and blow back into the fuel tank, then blow with light pressure into the carb and let fuel out the return hose..