2005 Yamaha F90TR 90HP Outboards Factory Service Manual, Page 229Get this manual
Bracket unit
Is it closed? Yes Check the power trim and tilt fluid level
Close the valve
At specified level? Yes
Add fluid to the correct level
Disassemble the power trim and tilt unit, and then check the filter for debris or dirtStuck foreign substance or clogs? No Check the fluid passages for clogs or debris