goes up more than the others, that generally indicates worn bores or ring problems.If a low cylinder doesn't increase from the dry to the wet that indicates valve problems, although this is generally accompanied by a regular beat in the exhaust or intake, indicating an exhaust or intake valve respectively.18V high compression are slightly higher at 9.0:1 and 170psi at 275rpm.
a sound engine, fumes aren't lost to atmosphere from any other place like oil seals and gaskets, but are burnt in the engine.
The PCV valve consists of a sprung diaphragm and valve.
One tip may be to disconnect the fuel pump and run the carbs dry before starting the test, i.e. I say this because although I have had my Gunson's compression gauge for about fifteen years I can't have used it more than ten times in that period, and yet when I lent it to a neighbour recently it wouldn't hold the pressure, because the hose had perished right by the brass fitting that screws into the plug hole.
It was fine just 1/2" back from there, so I trimmed it back and secured it with a clamp and it is working again, but it did make me wonder if it had sucked fuel in during the test (throttle wide open remember) and that had perished the hose.
The port on this valve is connected to a port on the front tappet chest cover, which contains a wire gauze mesh that acts as an oil-trap as well as a flame-trap.