tilt/trim raising by itself (really stumped)

[alexb6467]

hey guy/girls i have a real tricky question here. i have a 2001 mercury 2.5 sport. this engine was sitting for a year and after using it i noticed that the engine was in an upright position. i tried to put it down but it wouldn't go up or down. it just made a struggling sound. i was able to get it down by putting some wheight on the engine and rocking the trim button up and down. it would go down but within an hour it would be back in the upright position again.
i could use any help or ideas i can get.

thanks fellow iboaters

 

[WillyBWright]

Re: tilt/trim raising by itself (really stumped)

It's probably a corroded trim switch. The Mercury ones are usually pretty reliable. The most likley culprits are others fitted by the Boat manufacturer. If any of them (Merc or Boat) feel funky, that would be the one to concentrate on.

 

[Chris1956]

Re: tilt/trim raising by itself (really stumped)

Alex, During a severe rain storm, some water got into my PTT toggle switch and put the outdrive fully up and blew the fuse. I ended up taking the switch apart and cleaning it up.

 

[alexb6467]

Re: tilt/trim raising by itself (really stumped)

hey guys thanks for the ideas, although i don't think its the switch. i dissconected the battery this morning when i had the engine in the down position and within an hour it had slowly made its way up. it seems like there is still pressure on one side of the piston that is causing it to go up. if anybody has any other good ideas that would be awesome. or were i could find a schematic for the hydraulic pump assembly.
thanks again iboaters

 

[kingfish62]

Re: tilt/trim raising by itself (really stumped)

Try a complete drain and refill of the hydraulic fluid in the system. Once you think you have it empty leave the drain open and manually lift and lower the engine several times to ensure it's completely empty. Refill the system and do a bleed of air from the lines.