300XS trim cylinder leaking down

[2SKATERS]

I just bought a 30' Spectre with twin 300XS motors and am having a problem with the trim cylinders on the right motor. Hoping someone can shed some light on what is going on.

I can trim up both motors in my garage and slowly the right motor will start losing trim. You can actually hear the cylinder make a sound as the motor goes down. When running boat I leave the trim at parallel and that motor will go into negative trim during acceleration.

I have checked all lines and there are no leaks. The motors have 135 hours.

[Duro78]

Have you checked fluid levels? Made sure release valve is closed tight? If all checks out the valves are probably leaking which explains the slow decent. Do you have a service manual? If you do in the trouble shooting section it'll show you the culprit to your problem. I had the same problem it turned out the relief valve was slightly open. If your valves are leaking you can send it in and have them replaced

[XstreamVking]

Manual release valve on starboard side. O-ring goes bad and will let it leak down real slow. You might get lucky and it is just turned out some. Big straight slot screwdriver is the tool. Valve is plastic so go easy on it. Just check and replace the o-rings.

[2SKATERS]

Thanks for the responses.

All lines are tight. Don't see any leaks. Fluid level is right at the minimum line. Fluid appears to be red like transmission fluid.

I have the Mercury racing trim pumps mounted inside the boat and I don't see any valves on them. Unfortunately I do not have the service manual.

[Duro78]

. Since you did the initial trouble shooting the seals on your valves probably need replacing. That should take care of your problem.

[Duro78]

Manual release valve on starboard side. O-ring goes bad and will let it leak down real slow. You might get lucky and it is just turned out some. Big straight slot screwdriver is the tool. Valve is plastic so go easy on it. Just check and replace the o-rings.

That was my exact problem

[2SKATERS]

Manual release valve on starboard side. O-ring goes bad and will let it leak down real slow. You might get lucky and it is just turned out some. Big straight slot screwdriver is the tool. Valve is plastic so go easy on it. Just check and replace the o-rings.

My trim pump motors are mounted inside the boat and are not part of the ram on the transom. The trim ram is a single HD ram without and kind of relief valve on it. These are 2016 300XS Mercury racing motors.