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  1. #1

    Default Force trim pistons back on OMC (Johnson 120) with broken trim motor?

    Hello fellow boaters,

    Caused myself a problem in the midst of the boating holiday here. A few weeks ago, the power trim/tilt motor gave up. Luckily the Johnson got stuck in full down position, which for this boat is optimal for planing speeds. However, my fix-it-myself desire urged me to give it a go so I turned the bypass valve for manual tilt and raised the motor by hand (boat in the water). When doing so, the two trim pistons popped out from their all-the-way-in position, probably from some remaining pressure. And now, of course, theyíre stuck in that position and canít be forced back, nor by the weight of the engine itself or with me standing on it. And this full-upp trim position makes the boat hopelessly slow and inefficient, hardly managing to push it over planing speed.

    Now Iím hoping for a way to force the trim pistons back without having to take the boat out of the water. Is there another valve that can be turned to release the pressure in the cylinders, without oil flowing out/water flowing in?

    Any help appreciated!

    Cheers from the Swedish archipelago.


  2. #2

    Default Re: Force trim pistons back on OMC (Johnson 120) with broken trim motor?

    If we only knew witch j120 you have?
    Are you sure its the motor?
    No other manual valve.

  3. #3

    Default Re: Force trim pistons back on OMC (Johnson 120) with broken trim motor?

    Quote Originally Posted by Rwbutler View Post
    If we only knew witch j120 you have?
    Are you sure its the motor?
    No other manual valve.
    Itís a 1991 VRO. Yes, either the motor or pump is stuck. The relays output voltage accordingly, and thereís a significant voltage drop when they engage, suggesting motor stall.

    If I were to tilt the engine all the way up, I suppose I would get acces to the motor. Would it be possible to unmount it and manually turn the pump shaft or whatever the connection there is?

  4. #4

    Default Re: Force trim pistons back on OMC (Johnson 120) with broken trim motor?

    Yes,it is possible,but very difficult. Not a project to do in the water. Once motor is unbolted see if it works.

  5. #5

    Default Re: Force trim pistons back on OMC (Johnson 120) with broken trim motor?

    Quote Originally Posted by Rwbutler View Post
    Yes,it is possible,but very difficult. Not a project to do in the water. Once motor is unbolted see if it works.
    Thanks,

    Will need to repair or replace the pump motor anyway so easier to do that if the boat has to come out of the water either way.

  6. #6

    Default Re: Force trim pistons back on OMC (Johnson 120) with broken trim motor?

    That top pin is really tough to get out. I used heat ( carefully), and a mix of power steering fluid and acetone as a creeping oil. The boat definitely has to come out of the water. It is a a tight fit altogether even with motor all the way up and supported. Patience is your friend.

  7. #7

    Default Re: Force trim pistons back on OMC (Johnson 120) with broken trim motor?

    Quote Originally Posted by riopga View Post
    That top pin is really tough to get out. I used heat ( carefully), and ...
    Thanks,

    Iíve been hoping for an emergency fix by just bleeding the unit at a location that would drain the lower part of the trim cylinders. But, looking at the flow chart, I canít see that any of the valves or caps accessible without removing the unit would do that. Any suggestions?

  8. #8

    Default Re: Force trim pistons back on OMC (Johnson 120) with broken trim motor?

    Remove trim pistons,suck out oil,reinstall trim pistons

  9. #9
    Join Date
    Feb 2001
    Location
    Central West Florida
    Posts
    15,795

    Default Re: Force trim pistons back on OMC (Johnson 120) with broken trim motor?

    [QUOTE=Rwbutler;690114]Remove trim pistons,suck out oil,reinstall trim pistons[/QUOTE]

    Yeah... That would do it, BUT, if that rig's still in the water, it would be next to impossible to keep water from getting inside of that PTT unit which usually leads to kissing it goodbye.

    Do your self a favor, pull the rig out and have the unit repaired properly... The most reasonable route to go.
    We occasionally have questions. If you fail to answer, it may affect ours.

  10. #10

    Default Re: Force trim pistons back on OMC (Johnson 120) with broken trim motor?

    [QUOTE=joereeves;690117]
    Quote Originally Posted by Rwbutler View Post
    Remove trim pistons,suck out oil,reinstall trim pistons[/QUOTE]

    Yeah... That would do it, BUT, if that rig's still in the water, it would be next to impossible to keep water from getting inside of that PTT unit which usually leads to kissing it goodbye.

    Do your self a favor, pull the rig out and have the unit repaired properly... The most reasonable route to go.
    @Rwbutler But of course! Didnít think of that. Just need to find or make a suitable tool. And thank you joereevs, Iím generally a bit to gung ho, sometimes worsening the situation. Iíll secure the boat in a way that will keep the watee out, perhaps semi out of the watee.

  11. #11

    Default Re: Force trim pistons back on OMC (Johnson 120) with broken trim motor?

    [QUOTE=Swedishboater;690118]
    Quote Originally Posted by joereeves View Post

    @Rwbutler But of course! Didnít think of that. Just need to find or make a suitable tool. And thank you joereevs, Iím generally a bit to gung ho, sometimes worsening the situation. Iíll secure the boat in a way that will keep the watee out, perhaps semi out of the watee.
    Use your wifes turkey baster.
    Semi out of water is the same as in the water!

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