Trim works both up and down but tilt up stops

[1pooldoc]

Yesterday while fishing my tilt on the yamaha quit working. Now the trim will work throughout the up and down cycle but "up" stops when trim cylinders are fully extended. Trim motor still running but no lift in tilt mode. Had to get motor home with no support due to not enough lift. Thank God the trim had enough lift for skeg to clear. Could this be a fluid or air problem or is there a valve inside the pump regulating the fluid flow and it has a problem? 200 LB Yamaha motor. TIA

[yam911]

Suspect it is an F200LB.

Trim it up as far as it will go. Loosen the valve on the trim and tilt unit while holding the motor up. Then grab the lower unit and manually raise the motor to the full up tilt position. Use the lock to hold it up. Then check the fluid level.