Merc 1996 90HP Trim/Tilt Problem

S/N: 0G279254 Model#: 1090412RD Uses 3-wire (Black Fill Plug) unit. Have shop manual, all electrical checks out fine but it does not say anything about this condition. In down position, tilt motor runs but will not lift motor. Backed off the manual release valve but still could not lift motor. My "good neighbor friend" then removed the manual release valve which the shop manual says "do not do this". Oh well, sill cannot raise motor. Finally got enough strength (a lot!) together to raise the motor and chock it in the full up position. Not sure where to look from here. Since tilt motor runs I suspect pump/manifold. How can I tell? Is there a rebuild kit for the manifold? Have not removed the Trim/Tilt unit yet.

Re: Merc 1996 90HP Trim/Tilt Problem

To be honest with you I hope I don't have problems in this area. I also have a shop manual and there is a lot to that little sucker.....too many pressure relief valves for me.

Good Luck,

Mark

Re: Merc 1996 90HP Trim/Tilt Problem

I would be looking for a stuck solenoid/relay.

Re: Merc 1996 90HP Trim/Tilt Problem

Thank you for the replies...

I tested both solinoids in the system and out of the system (bench test). Both check good. All electrical checks per manual checked good. Service manual states that with motor in the full up position there would be no pressure and the fill plug could be removed for inspection. Not the case, once I forced the mortor to full up position with the relief valve "opened" there was still high fluid pressure when opening the fill plug. I suspect it is a hydraulic problem. The service manual only discusses "bleading down" and "no reverse lock" conditions. It does not discuss any symptoms like these.

Re: Merc 1996 90HP Trim/Tilt Problem

One other thing...the motor does run "whine" when pushing the up button AND the down button. The pitch of the when changes between positions.

Re: Merc 1996 90HP Trim/Tilt Problem

With the manual release undone, two people should be able to easly lift the motor, does it stay up when you lock the valve.?

Re: Merc 1996 90HP Trim/Tilt Problem

Two people were not strong enough to lift it. Once I got it blocked I refilled the fluid and removed the upper pin from the piston and tried to cycle it up and down again with no weight on it. The piston would go down only if I pushed on the pin and it was very jerky and rough. The piston would not go back up even though the pump motor was running.