Yamaha 115-225 HP Outboards Service Manual, Page 184Get this manual
po_W_E_R_T_R_IM_A_N_D_T_IL_T_U_N_IT K51015-0
POWER TRIM AND TILT UNIT
DISASSEMBLY Referring to the exploded diagram, disassemble the power trim and tilt unit
1Do not wipe components of the hydraulic system with rags or paper tissues etc, as fibers from such entering the system will cause malfunction2After removing the tilt motor or oil-reservoir, do not depress the tilt-rod or trim-rod which may cause hydraulic fluid to be ejected from the port
1) Turn the manual valve fully towards the manual position
2) Remove the delivery pipes and the hydraulic-fluid level-plug3) Remove the hydraulic-fluid reservoir and the tilt-motor4) Remove the strainer, connector-shaft and the gear-pump5) Remove the O-rings and the down reliefvalve complete