Alright i have a 1992 force 120 hp 1208x92c. The tilt and trim holds the motor up just fine when im out of the water, i can leave it up all night and wont leak down at all. When i went to the lake today i took the boat off the trailor and everything seemed fine. tilt stayed up while idleing through channels. When i got to the main part of the lake i got on the throttle and once i hit 10mph the outboard just dropped and would not raise while going over 10mph. If i slowed the boat back down to under 10 i could raise and lower the motor and it would stay just fine. Any ideas on what could be happening and what i should do first?