I need help.I have a 95 xr6 150 my power trim wont hold the motor up,the piston has been apart no bad o rings the motor is brand new,and we pulled the pump all apart cleaned everything it all looks good im so lost any ideais???????????????????????????

Did you ever find what was causing your problem ? i have 175 hp does the same , went through tilt cylinder cleaned ,replaced o rings . port side trim cylinder did the same , replaced manual relief valve , still leaks down

The Port rim piston is fairly common for leakdown issues.
It has a check valve at the bottom of the piston that can fail.
Next I would pull the manual relief valve out and verify the O rings are still intact.
After that you need to pull the pump out. Flush it in mineral spirits, put it back in and pray.