89 90 hp mariner trim issu

[worc guy]

I have a 1989 90 hp Mariner that is stuck in the up position. The trim motor runs in both directions but the main oiston does not. I filled the resivoir with fluid, it did not take that much. Any Ideas

 

[galamb]

Have you tried the manual release screw to see if the motor will come down?

If you are unaware of it, it is located on the motor bracket itself that connects the motor to the boat. Standing behind the boat (looking at the prop), the release screw is on the right hand side. It is located near the bottom of the bracket that is bolted to the transom of the boat. The bracket is (kinda) triangular shape near the bottom. You will see a couple of bolts but their is a screw there (takes a flat head screw driver).

Back out that screw, no more than 3 turns. The motor may start coming down once you start turning it. If not, back it out and then try to push the motor down.

If it doesn't come down on it's own or you have to put significant pressure on it and it barely comes down or you can't budge it there is a chance that the "stem" on the manual release valve has broken off or the rubber gasket (o-ring) on the manual release has broke/deteriorated and is blocking the hydraulic channel that would prevent the motor for coming down.

Try the manual release first and report what you find...