Sterndrive Trims Up like it should extremely slow down

"i have a 1975 winner with mer

"i have a 1975 winner with merc 165 I6. trims up great and fast but extremely slow down, if not at all unless someone puts weight on it as switch is running in or down position. installed new pump and still does the same, even bypassed all the extra lines and ran the down line straight to the transom and same with the up. still no difference and after in the down position i can lift the outdrive by hand all the way up. tried reversing the up and down lines and down then raises very slowly as it did lower. and up still raises. im lost, kinda hard to back of the trailer when the prop wont stay in the water"

One of the trim rams or both s

One of the trim rams or both should be rebiult. They are seviceable. or take a close look at the lines and follow from the pump to the trim rams and make sure no kinks or collasped lines. Those old fiber lines it is difficult to se the insides if collasped.

it wouldnt lift ok like it doe

it wouldnt lift ok like it does if one or both of the rams are bad would it?

"I am not sure I want to answe

"I am not sure I want to answer that question........................................

Think of pushing something or pulling something

in one way it is easier than the other and if the is a issue then it may only be affecting one direction,

STUCK MEMORY PISTON in the trim ram I bet......

If you need to open/rebiuld one of them and considering the age of the boat I think you can answer that one"