Yes, it needs the spring and I would probably skip the gumout.
Those little o rings don't like the stuff. Hopefully the tank and line was cleaned before the installation.

Yes the tank was drained and 'looked' clean. The fuel line was replaced with a new one. I wasn't sure about the spring because when I experimented with putting it in, it seems to "pre-load" the nozzle, i.e. put tension upward on it so it seems it would be very hard to insert the bowl assembly back upward into the carb and secure the metal clip. Do you think the missing spring is what is keeping it from running? I thought maybe I had a blocked passage in the carb therefore the Gumout idea...I'm running out of ideas.

Update...just re-installed the float bowl with the spring in place. Still won't start. Not even with starting fluid. Any ideas what else to check?

How does the compression seem? Occasionally these can have a valve that sticks open if they have sat a while. The other question is does it have spark. A bent control at the side of engine or a cable that doesn't quite fully open the kill switch possibly?

RE: compression, it takes the normal effort to crank the engine (pull the cord). What valve are you referring to?

RE: spark, I removed the spark plug, attached the lead, and leaned it up to the head-then pulled the cord, it did make spark on every pull.

RE: kill switch, the cable seems to pull the lever fully back in it's travel...

It should kick over with starter fluid, even without the carb installed. The key is to use just a tiny amount or the plug gets wet. Try another new plug and a tiny bit of starter fluid. If that doesn't work, check the flywheel key.

Verify that the spark can jump 1/4".

It has a compression release for easy starting, and an engine in good condition will obviously start with the lower compression. But, if an intake or exhaust valve is stuck open from a long period of storage without proper preparation, it won't start.
They are set up for lean running and will not start without a working primer. The primer may take 5 or 6 good pushes before it's rich enough to start, but it should start briefly with the primer even if the carb cannot meter any fuel.
Are you using new, fresh fuel? My 'mix' for my Tecumseh and other 4-cycle mower engines is Sta-Bil 'Marine' stabilzer/cleaner and Marvel Mystery Oil with mid-grade gas. Of course, this won't help until it's running.
Does the plastic float bowl have the metering bolt in the bottom securing the bowl to the carb? If so, clean the orifices in the bolt including a possible very small one near the top of the threads.
For a stuck valve - take out the plug and shoot a 1:1 mixture of gas:Marvel Mystery Oil into the cylinder. Pull it through once or twice, replace the plug and let it sit overnight.

I'm using fresh gas, and this engine has the plastic float bowl (brand new) that secures with a metal wire clip. The drain screw is horizontal, not on the bottom.

I'll try the Mystery Oil trick on the valve.

Question, if my kill switch was faulty, would there be zero spark? I do have spark...

If you have compression, spark and fuel, it should attempt to start with or without the carb installed.

At this point, you may have to take off the head and look at the valves. You kill switch does not appear to be faulty.

Update-another new plug, still won't start. Tried the Mystery oil in the cylinder overnight. Removed plug and slowly turned it over. Replaced plug and still won't start. I guess next step is disassembly? Pulling the head? Is there an online manual or site that has exploded diagrams or instructions?

Try this site:

http://www.cpdonline.com/692509.pdf

I would pull the head and verify that the valves close as the engine is spun. Will cost you a head gasket.

What tomplum said; the easy way didn't work.