Went to start to car one day, after a little misfire/stumble, engine does not start. Sounds like crank is spinning too easy so I check timing chain. Looks good, marks align. Check compression; does not move the needle. Lifters are moving, valves appear to open and close, no (obvious) excessive lash. What else could it be? Please help.

Are all cylinders down on compression?

Recheck the timing marks. Also do some research on how to set the cam timing. Some engines ( in general ) no longer have shaft keys and use a taper fit and lock tools to set cam timing.

Timing marks line up, unless I missed something. Small notch on the cam lines up with seam of cylinder head. I haven't checked compression on every cylinder, but those I have don't register any pressure. I can hear compression load as engine cranks, but doesn't move the gauge needle. Plug removed from each cylinder; only gauge sealing one cylinder.

Put the compression gauge on your lawn mower / other engine and make sure it works.

Shop manuals usually have a spec for intake valve opening, find that and compare to your engine.