My Harbor Freight compression tester which Has always read crazy low, like 40psi on a bike that was running great had a long hose.
I did a drill compression test on the moby engine I’m putting together and got 60psi. Thought about this thread, did as Jbot suggested and cut the hose down to nothing. I’m still using the fittings it came with though. Same engine now reads 180 psi.