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

S

Swedishboater

New member
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, they’re stuck in that position and can’t 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 I’m 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.

 
Rwbutler said:
If we only knew witch j120 you have?
Are you sure its the motor?
No other manual valve.
Click to expand...

It’s a 1991 VRO. Yes, either the motor or pump is stuck. The relays output voltage accordingly, and there’s 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?
 
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.
 
riopga said:
That top pin is really tough to get out. I used heat ( carefully), and ...
Click to expand...

Thanks,

I’ve 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 can’t see that any of the valves or caps accessible without removing the unit would do that. Any suggestions?
 
Rwbutler said:
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.
Click to expand...
 
joereeves said:
Rwbutler said:
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.
Click to expand...

@Rwbutler But of course! Didn’t think of that. Just need to find or make a suitable tool. And thank you joereevs, I’m generally a bit to gung ho, sometimes worsening the situation. I’ll secure the boat in a way that will keep the watee out, perhaps semi out of the watee.
Click to expand...
 
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