DON PLEASE HELP ME

[TTU-kz]

I have a 1990 90hp Mariner and i'm having trouble with the trim. The motor will trim up and down sometimes but will become stuck in different places. When it becomes stuck the trim motor will just make a whining noise. If you leave it alone, slightly lift it up, or push it down it may start working. It seems as if only happens when trimmed all the way up or all the way down. The trim motor was replaced in April of 2010 with MES Model T1075M. which has the 2 wires. If you have any suggestions I would greatly appreciate it. Thanks.

[EuropeanAM]

A good starting point would be to check the trim fluid QUALITY and LEVEL.

Raise the engine ALL THE WAY UP, and set the SAFETY LATCH.

Slowly, and carefully remove the fill screw from the resevoir. NOTE: It may be Pressurized.

With the BOAT and Trailer LEVEL, the fluid level should be "just to" the bottom of the threads at the fill screw. Fluid should NOT appear "milky"- and should not be "spewing" out of opening (overfull).

Top off (or drain excess) as needed with Mercury Power Trim and Steering Fluid.

Reinstall fill screw... remove safety latch, and cycle trim a few times to see how it does.

Report back with results, of course.

[TTU-kz]

I checked the fluid and levels are fine. It looks just as you said it should. It is right at the bottom of the threads and doesn't appear to be milky. I am starting to believe that it is the cylinder next to the motor that is not functioning properly because the motor is trying to work. When the motor went out two years ago it wouldn't do anything ( not even make the whining noise). I hope that the cylinder is not the problem because i heard they are pretty high priced parts.

[EuropeanAM]

You might want to take a closer look/feel of the trim motor itself, in an effort to determine which of the below is the case:

-Trim motor is spinning, but fluid is not properly pumping within the system (possibly due to a bad check valve, debris, or a failing pump)

-Trim motor is simply "whining/buzzing" as it ATTEMPTS to spin (but cannot actually rotate at the speed required to function the pump). This would require replacement of the trim motor.

[vatreefarmer]

I had a bent piston/rod that gave me similar symptoms. Biggest issue was the motor couldn't trim all the way down without putting pressure on it