You didnt say where you are? I guess its USA as 'tear down' is an American expression, we would say 'strip' here.
In the UK we had two different carbs although these were basically the same, they were numbered 2H500 and 3U500, they had different components in them.
I 'think' the American one was akin to the 3U500 and had an interference fit emulsion tube (AKA needle jet), when you strip the carb down for it's thorough clean...tap this out from the top (downwards) it will not need much of a tap so take it easy as it's soft brass. You may find it gunked up like this so you have to get it out to clean it.
also take out the other jets...main jet...pilot jet and the float needle valve (dont damage or lose the gasket under this)..take out the air mixture screw and dont lose the O ring if it has one (which I think it may well have)...take out the choke plunger and check the rubber seat is not damaged.
Clean the carb body with carb cleaner and blow through any little passages with compressed air or an air duster.
Re-assemble it all and check the float height is set to 21mm (gasket removed) see picture
as has been said set the air mixture screw to 1 and 1/2 turns out from gently closed, then adjust the throttle stop screw for idle at around 1200rpm
As fpr cpmpression I reckon 100psi should be fine and did you do this test with hot engine?
...Paul