Won't get answered in the 'technical/ref' section, you  need to post this in Rubber Side Down section. Or wait till it gets moved.

If youve been grinding on the starter with no Joy
Time to charge the battery
Itll turn over okay, even when the battery voltage is too low to fire the Sparky makin box,,


That isnt to say
Ether is not a good thing to have when youre havin problems gettin an engine to light off,,

I use it often when Im firing something up..
Just know,, Ther Is a Too Much,, Start small,, monitor battery voltage when the starter is spinning,,
Someone will surely offer the minimum votage that fires the plug,,
I dont remember

And, If the carb bowl is empty and youre not using Prime,, Its not gonna start gettin gas for a long time.

Thank you for your time. Yes it ran when I got it. All I removed was the head cover. Did not take cam chain or tensioner off. When head cover was off I set to TDC lining up the marks on the cam and the crank (cover was off).  Put back together and will not start even with ether. Will get a pop or two then just cranks.  The compression test I disconnected decomp plug, throttle wide open and does not build pressure with each crank.  Goes up a little then flatlines for a few cranks then up again to 160 psi. It’s like the timing is off but no idea how that happened.

OK, so it was running before you opened it up and you didn't tamper with the cam or cam chain.  That would indicate that the cam timing is correct or at least close enough to run.

Your compression pressure of 160 psi is certainly in the ball park.  It's normal.  But your description of how the pressure builds seems unusual.  It should be a nice pump at evenly spaced intervals, with the amount of buildup decreasing gradually until it flatlines.  First pump like 100 psi, second pump 130 psi, third pump 150 psi, fourth 155 psi, fifth 160 psi, 6th,7th, 8th flatline.  What you describe could possibly be an indication of valves hanging open (but seems to me it should start).  Double check the valves by placing the engine at TDC compression and making sure you can move the rocker arms to the right with your fingers.  You should be able to push the rocker a bit to the right and it should spring back to the left when you release it.  This is like a five-minute job.

Have you tried using a jumper battery?  JOG mentioned that it won't start if igniter voltage drops below 10V.  Hook up a jumper battery and see if it starts and runs.