motor drifts down

[grizzlyadams73]

the power trim on my outboard motor does not want to hold. put the motor up and a hour later it is in the down position.

how do i fix this?

[Damark Marine]

What type model ect are we dealing with?

[grizzlyadams73]

it is a 1990 50 hp mariner

[FishTales]

Grizzly,
The lift motor runs/ pump runs / valve shifts / cylinder raises motor.
The lift motor stops / pumps stops / valve closes / oil stays in cylinder holding motor up.

Either the valve is not closing / or the oil is bypassing the seals in the cylinder.

You didn't mention if there are any leaks in the system.
Not much else to go wrong.
Rich

[john warren]

yup,,,,what he said!

[Damark Marine]

Here is a quick copy paste from the service manual. I can get as detailed as you would like but ck this first.

IMPORTANT: Operate Power Trim system after each check to see if problem has been
corrected. If problem has not been corrected proceed to next check.
1. Check that manual release valve is tightened to full right (clockwise) position.
2. Check trim pump fluid level with outboard in full up position and fill if necessary. Refer
to Bleeding Power Trim Unit.
3. Check for external leaks in power trim system. Replace defective parts if leak is found.
4. Outboard not holding tilted position (falls down to trim position) indicates debris or defective
components in trim assembly. Clean or replace components as required.


These are just the basics. If you are falling down & wont hold the tilt position and the manual valve & o ring are ok the problem is going to be in the valves either debri or damaged. If that is the case you may decide to take it in or if you are kinda handy you can dig further into it.

[b2theill]

first thing i would do is make sure your manual release is snug. if it is you are having a leak problem. internally or externally