Don't ever pressurize more than 10 psi, you risk blowing a perfectly good seal right out of the block. If a leakage is determined, hook it up to shop pressure regulated to under 10 psi to provide constant pressure. Then take a squirt bottle with soapy water similar to if not a little richer to the dish water you use and squirt on seals, gaskets, insulator block, impulse hoses, intake manifolds, anything/place where a leak in the crankcase can occur to find the leak by looking for the soapy water to bubble.
Note, if leak down test only shows leakage at vacuum but not under pressure, it is a crank seal. It's a little harder to see which seal is bad when it fails at vacuum only but sometimes you can see your soapy water disappear while pumping the hand vacuum rather then bubbling. If not, replace both crank seals.
Nevada! The last free state!
Retired Briggs MST, Honda Top Tech.
Currently full time experienced novice fisherman.
You should've been here yesterday, the fish were really biting..