Re: part time trim
this is strait form the manual , tilt the engine to full up position, clean area around fill plug ( motor will have two plugs top is fill plug) remove the plug and visually check the fluid level in the pump reservoir , it should be to the bottom of fill hole threads, top up if necessary with omc power trim fluild .
but it sound like your trim switch is going bad, if it is sparatic, could be switch or loose connection on your solinoid, pull off the cover and check your connections , look for the wires it is easy the blue wire is your up solinoid and the green wire is your down , blue of the sky and green for grass. hope I was some help..