You have to first determine if the problem is lack of fuel or lack of
ignition.  One way to check ignition is to pull a spark plug wire,
attach an old spark plug to it, ground the outer electrode by holding
it against engine metal and crank the engine.  You should see a
strong, consistent bluish spark.  To check fuel, liberally squirt a
flammable solvent such as WD-40 or CRC into the air cleaner inlet and
then crank the engine.  If it starts momentarily and dies, then the
problem is lack of fuel.  Good luck.  Al

sounds like its flooded, common problem

Hold your foot to the floor and crank it, don't let up till its starts then
keep it running till it clears the excess fuel out of the cylinders