Trim failing?

[aswilber]

I have a '99 Mercury 60 hp 2 stroke and I think the trim is giving up. Here are the symptoms:

When I am under power and try to trim the motor up in order to clear an underwater obstacle, the motor trims up a ways and then slowly slides back down ( but not all the way down). When the boat is not under power, I am able to trim the motor all the way up, so I am assuming that the movement of the prop is "pulling" the motor back down into the water.
Is this a way of the motor preventing itself from raising to a point where the water pump would be unable to pickup water?
I have checked the trim oil level and it is up to the screw as it should be.
I have also tried pulling the motor down when the boat it on the trailer, but am unable to get it to behave as it does under power.

Any suggestions would be great!

Thanks,


Andrew

 

[aswilber]

Re: Trim failing?

Anyone have an idea of the cause?


Thanks

 

[JB]

Re: Trim failing?

Well, Andrew, this is a Boat Forum and it specifically says "Not Engine Topics".

I will move this to the Mercury Outboard troubles forum. Perhaps a Merc outboard expert will see it there and offer some advice.

 

[aswilber]

Re: Trim failing?

Thanks JB...sorry for the added work on your part.

 

[gjblanchard]

Re: Trim failing?

I had a somewhat similar problem on a 2007 Merc 50 ELPTO 2 stroke. After searching on this forum I found it was either the pilot check valve (behind the large screw on the lower portion of the hydraulic unit) or, less likely, the pressure release screw on the side of the power trim unit (nylon screw on rt. side, with an access hole through the transom mounting bracket) was loose.

I checked the pressure release nylon screw and found it was about 1/8 - 1/4 turn loose. After tightening it, my leak-down problem disappeared and the power trim works perfectly. I hope you are equally lucky!

Cheers, Gary

 

[aswilber]

Re: Trim failing?

Thanks a bunch for the advice, Gary.

I am familiar with the screws you are referring to and will check them out in the am. I appreciate the help!


Andrew

 

[klinger]

Re: Trim failing?

I have the same problem with the tilt on my 50 hp 1999 Mariner 4 stroke not holding.I was told by a marina that it was probably the relief valve.I replaced it at a cost of $40.But it did not help.there are 3 o-rings on the relief valve and they all look good.I do have it turned in all the way.The paper work I got with the kit says to discard the black valve and replace it with the new natural colored one.Mine already had been replaced it was a natural color. Does any body have any ideas for me? I dont think its not old enough to be having that kind of problem. Has there been anykind of a recall because of a defect?
Thaks - Klinger