The cylinder leak down test only works properly with both valves closed (distributor rotor pointing at the plug wire for the cylinder youre testing, brakes set and/or wheels chocked both directions), and air pressure introduced into the cylinder with an air line quick connect fitting made from an old spark plug shell. Air out of the carburetor- - - -bent, stuck, or burned intake valve. Air from the tailpipe- - - -bent, stuck or burned exhaust valve. Bubbles in the radiator- - - -cracked head, cracked cylinder wall, or blown head gasket. Air from the oil filler cap- - - -hole in a piston and/or broken piston rings. Very low or zero pressure means a valve job, or an engine overhaul is coming soon. Sticky valves seldom cause a total compression loss, just lower compression on the affected cylinder(s). Good call on the tight valve adjustment!- - - -that's a definite possibility. Good luck!
Jerry
