Re: 1985 Johnson 50hp trim/tilt
it is a prestolite. same pump as a Chrysler/Force except with larger mounting plate and different port threads. Fixing one is same as fixing the other.
If the motor spins, if there is fluid, if there are no external leaks, and it still doesn't lift-lower properly .... then your valve body (aka pump) has a problem. Drift down is a leaky check valve. Failure to lift can be loose manual release, broken manual release, or blown out check valve. Lifting but not lowering is a pressure lock usually caused by improper spring compression on regulator.
