1985 OMC 3.8L Trim Not Holding

Joined
Mar 29, 2017
Messages
27
Okay, so I am near the end of my boat restoration and I hooked up the battery and trimmed the motor down( front of the engine came up) and after 20 minutes the engine finds its way back to the trimmed up position( front of the engine back down). Any thoughts as to if this is an easy fix? Or is this normal being that the lower unit is not on yet and it slowly goes back down due to no force from the outdrive pushing on the boat as if it were underway. Thanks
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
Staff member
Joined
Jul 23, 2011
Messages
47,306
I am guessing you have an OMC stringer drive.

if so, no, it is not normal for the front trim ram to move.

if you are refering to the tilt drive, if the clutch is not set right, that can drift down.
 

kenny nunez

Captain
Joined
Jun 20, 2017
Messages
3,056
You have a hydraulic leak. Hopefully it may be a rusted line that can be replaced. If no leaks are resent then one of the hydraulic cylinders on the side of the engine has a bad piston seal. Sometimes the cover of the ram housings would crack. Check all the connections at the pump also. The pumps usually did not give much trouble on the hydraulic side.
 
Joined
Mar 29, 2017
Messages
27
Yes. It is a stringer. I have not noticed any fluid from the hoses since I've had the engine. It's been in the garage out of the boat for one year and I just recently installed back in the boat and hooked up the battery and trimmed the motor. Doesn't appear to be any cracks. I will inspect the threads on the hoses closely when the sun comes out. I suppose I could throw more money at my project. I almost have this thing floating.
 

Howard Sterndrive

Rear Admiral
Joined
Nov 5, 2008
Messages
4,603
if no external leaks, you'll need to reseal the mounts (cylinders) . They use Parker T-seals which you can get at a hydraulics shop, or you can just order the omc ones from BRP. I used to make up sets and sell them on ebay about 10 years ago - seemed to be a lot that needed resealing at the 20 year old mark.
 
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