1987 50HP Evinrude tilt/trim pump question.

James R

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Feb 1, 2007
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2,660
The problem. Tilt trim will not hold the motor up. It slowly drops right down from the tilt position to the lowest trim position. I have the OMC manual for this motor. The manual says to check the valve in the pump. The manual does not say what the valve is or how or what to check.
I note that there is a little sediment in the reservoir and I assume it is also in the pump.
Can you tell me about cleaning the "valve" whatever that is and about cleaning the pump.
I can see that there are two free floating ball bearings in the pump which move freely. I assume they are similar to check valves.
I appreciate any help.
Thanks.
 
D

DJ

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Re: 1987 50HP Evinrude tilt/trim pump question.

You have a "manual" release screw that is usually located on the Starboard side of the engine. It is in a recessed hole that is stamped "manual release". If that is not tight, it will do what you describe.

If that manual release has been used a lot, it may need a new seal/O ring.
 

James R

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Feb 1, 2007
Messages
2,660
Re: 1987 50HP Evinrude tilt/trim pump question.

Thanks DJ. That was the first thing I looked at. Everything looks good but I will replace the "O" ring when I reassemble I have it all on the bench, found someone had sheared the tilt piston mount bolt.They tried to fix it with JB Weld. I have it all down and will drill the old bolt out and fit a new one. at the same time I will replace the scraper seal and "O" rings in the Tilt cylinder. There is a very slight weep around the piston shaft.
I have the pump on the bench ready to be cleaned. Hope you can help me on this.
Thanks for the response.
Jim.
 
D

DJ

Guest
Re: 1987 50HP Evinrude tilt/trim pump question.

Thanks DJ. That was the first thing I looked at. Everything looks good but I will replace the "O" ring when I reassemble I have it all on the bench, found someone had sheared the tilt piston mount bolt.They tried to fix it with JB Weld. I have it all down and will drill the old bolt out and fit a new one. at the same time I will replace the scraper seal and "O" rings in the Tilt cylinder. There is a very slight weep around the piston shaft.
I have the pump on the bench ready to be cleaned. Hope you can help me on this.
Thanks for the response.
Jim.

OOOH, you need a maunal for rebuilding TNT systems. There is a lot of potential hydraulic pressure there.

Start simple and go from there.
 

James R

Commander
Joined
Feb 1, 2007
Messages
2,660
Re: 1987 50HP Evinrude tilt/trim pump question.

Thanks DJ. Someone should have the info on stripping and cleaning a simple pump. I don't think there is any manual because the pump is probably not rebuildable. But cleaning should be possible.Better to ask than **** it up, right.
 
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