As for your observed 50 psi compression reading, you need 70+ psi for most Honda Engines to run. First, do you know for sure that your compression gauge is reading correctly? You should check the engine with a gauge borrowed from a friend to confirm you are getting a good reading. The compression release, if working correctly, will not cause a problem when checking compression, as it is activated only at lower cranking speeds (around 200 rpm).
Assuming the gauge is reading correctly, check the compression dry. Then, squirt a little engine oil into the cylinder, rotate the engine to distribute the oil & check the compression again. If it is significantly higher (15-20 psi), you very likely have a piston ring problem. If the compression increases very little or none, you may have a sticking intake valve.
Also, you didn't indicate if your engine is a residential GC Series or a commercial GX Series.
