I bought a mower at an auction which was partially disassembled, but
all the parts were included minus a couple bolts. The flywheel and
magneto were off, the engine head was off, as well as all the covers
and the gas tank. I put it all back together.
This is an electric start push mower and has all the bells and
whistles. I put the head back on the engine as well as the flywheel,
and magneto. I connected the gas tank even though it's sitting off to
the side now (it covers most of the engine).

I connected a battery and turned the engine over. It spins nicely but
will not start. With the spark plug wire off the plug, I see a very
nice spark to the engine block, so I know it's getting a spark. I
also know it's getting gas, but in fact, too much gas because the
spark plug is getting soaked, and after cranking it with the
battery/starter for awhile the engine would get very tight because of
gasoline flooding. Pulling the spark plug made it turn easily again,
but the plug was soaked.

I put a vice grips on the gas hose to stop the gas from flooding the
engine. I still do not get even the slightest pop from the engine.

I put the spark plug on the end of the plug wire and can see a strong
spark on the plug tip.

There is still some gas in the carburetor, and I know the spark is
good. Why wont it start?

I have no idea why they had the head off, and the piston moves up and
down properly, so do the valves, and the cylinder is smooth. I
cleaned all the carbon off the head before I installed it. I can hear
the compression, and since the gas flooding caused the engine to cease
up, it's obvious there is compression. I dont have a compression
tester but I can hear the compression.

Since there is a good spark, some gas, and compression, what the heck
could cause it to not get at least a little pop?
What else can I check? I have worked on many mowers in the years and
never had one that wont at least make an attempt to pop.

This is a 4 cycle engine.

A few notes.
I put in NEW gas.
The oil is at proper level
This has a bulb for cold starting
I did NOT buy a new head gasket, but it was in good shape, and like I
said, it has compression.
I am trying to start it using an external battery charger, so it is
spinning fast enough.

Any ideas? I have run out of things to try?????

The only thing I can think is that there is just too much gas still
remaining in the cylinder, but I did turn it over quite a bit with the
plug removed.

Mark