After overhauling GX140 completely, won't start

Mine is a HRM215 SXA walk behind honda mower which is about 20 years old.

It ran fine but had oil leak that was getting worse. Plus it was getting increasingly difficult to start.

I took the engine entirely apart and replaced all the: gaskets, seals, rings.
Also replaced the ignition coils and carburetor.

It won't start. Here's what I tried so far:

1. checked the spark. Great spark!!!
2. Checked the compression. 105 PSI
3. Checked the fuel supply. There's plenty in the bulb of the new carburetor.
4. Tried opening the choke and spraying starting fluid into the carburetor.
4. A tech suggested it might be something in the head.
So I pulled the head off and discovered the valves were swapped.
So I corrected that
Again, I checked the spark, the compression, and still won't start.

By won't start,I mean:
The engine turns very easy now by pulling the cord (I cleaned lot of carbon buildup inside the engine.)
But it doesn't sound like it's firing at all.

How can that be when it has spark, compression and fuel?

I don't get it.

Any ideas?

After overhauling GX140 completely, won't start