The best way to get 0 compression across the board or even just the cylinder you were replacing valves for, is to not check the valve lash after getting the valves lapped/ground including the tip for the rocker area. The motor sure spins fast when that happens. Your valves are almost guaranteed hanging open right now!
... it doesn't take much at that speed to allow all the pressure to blow right on by.Just remove the rocker cover and rotate the crank until you cam has come off the lobe for the intended valve/spring combo and check for free play. If you can't move the rocker such that it clicks or so that you can fit a feeler gauge in to spec you probably have direct contact all the time and actual pressure keeping the valve open. Back off the adjuster nut (12mm) and adjust you valve (intake to intake spec, exhaust to exhaust spec) to cold specifications and then tighten the nut while holding your flat head screwdriver absolutely still - recheck the contact and adjust as necessary.
New valves are guaranteed longer than used ones would be - reason being that the valve face wears and so does the contact tip on the top of the stem. It doesn't take much to hang that valve open.
See if this makes a difference, it happened to me and I thought it wasn't going to make that much difference when the exhaust valves were done - wrong!
