Hey everybody. I'm new to the forum but I have been reading on it for some time now and found it quite useful. However, I'm having an issue that I just can't seem to get my arms around that I would like some guidance with.
I have a 1990 Bayliner cobra with a 1990 Force 120 outboard on it. When I bought it, the trim would only raise up when no load was on it and would slowly bleed down on its own. After reading on this forum for several days, I ordered new seals for the tilt and trim cylinders. I replaced them, but nothing changed. I then changed out the seals on the check valves on either side of the valve body. This corrected the system bleeding down on its own, but the system still wouldn't trim up while under way.
I then ordered a new pump and motor from DB Electrical and got it installed. The motor will now trim up when under way, but will fall under high load when attempting to trailer the boat. I understand the difference between tilt and trim so I'm careful to make sure that I'm still on the trim portion when loading on the trailer. Even when it's on the trim it will still fall just as I'm gettin the boat up to the front roller. Once it falls, it almost gets some sort of hydro-lock and doesn't want to pick up on its own even with the engine off. But if you help it up once, it will begin working fine once again even raising under load, then fall again the next time I go to trailer the boat.
I can get it to repeat in the garage by standing on the foot. It will hold up to a point, then it's like some sort of pressure relief valve lets loose and the motor falls all the way down; its not a slow gradual fall.
Does anyone have any suggestions as to what I should do next. I'm contemplating ordering new tilt and trim cylinders, and maybe another pump as I have read the new pumps aren't nearly as good as the original.
I also was curious if this could be cause by installing the tilt piston in backward? If I remember correctly it will thread on the rod either way and has some sort of pressure relief built into the piston.
Any thoughts would be appreciated.
I have a 1990 Bayliner cobra with a 1990 Force 120 outboard on it. When I bought it, the trim would only raise up when no load was on it and would slowly bleed down on its own. After reading on this forum for several days, I ordered new seals for the tilt and trim cylinders. I replaced them, but nothing changed. I then changed out the seals on the check valves on either side of the valve body. This corrected the system bleeding down on its own, but the system still wouldn't trim up while under way.
I then ordered a new pump and motor from DB Electrical and got it installed. The motor will now trim up when under way, but will fall under high load when attempting to trailer the boat. I understand the difference between tilt and trim so I'm careful to make sure that I'm still on the trim portion when loading on the trailer. Even when it's on the trim it will still fall just as I'm gettin the boat up to the front roller. Once it falls, it almost gets some sort of hydro-lock and doesn't want to pick up on its own even with the engine off. But if you help it up once, it will begin working fine once again even raising under load, then fall again the next time I go to trailer the boat.
I can get it to repeat in the garage by standing on the foot. It will hold up to a point, then it's like some sort of pressure relief valve lets loose and the motor falls all the way down; its not a slow gradual fall.
Does anyone have any suggestions as to what I should do next. I'm contemplating ordering new tilt and trim cylinders, and maybe another pump as I have read the new pumps aren't nearly as good as the original.
I also was curious if this could be cause by installing the tilt piston in backward? If I remember correctly it will thread on the rod either way and has some sort of pressure relief built into the piston.
Any thoughts would be appreciated.
