Any ideas on where to start looking for the problem?
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Any ideas on where to start looking for the problem?
Trim fluid in the cylinder.
O rings on the cylinder
Probably packing in the cylinder. I'm assuming going across the lake you are constantly triming up?
Schematics and parts list...
125 (4 CYL.) Mercury Outboard 0P325500 & Up Power Trim Components Diagram and Parts
Besides a spanner wrench to get the caps off, you should be able to do it yourself. You can build a spanner wrench if your handy...but you could probably find one or borrow one. If you are willing I'm sure we could help you through it. The hardest part will be getting the unit off the boat/motor so you can put if on the bench. I think once you got it off...and had a spanner wrench you could probably handle it. The most important part is to be VERY clean, and getting the correct orings in the right place and order.
If you don't know what a spanner wrench is...if you look at the top of a cylinder there will be two maybe four holes...a spanner wrench is a handle with two or so pins in them that go into those holes and allow you to spin the cap off.
Let us know if you need any help or have any questions.
I have a 2010 Merc 90 4 stroke that trims down on its own the more I increased power to get the boat to slide up on the trailer.
I do not have leaks and perhaps I am wrong, but I actually think it is some type of safety release thing.
Make sure the emergency release valve isn't loose too.
If that is not the problem, it will be the packing in the cylinders I bet. You might google the procedure to bleed the air out. IF it was low on fluid, it will have air in the system. Some are different than others. Some you don't have to bleed the air out.
Its self contained and even if the seals are not leaking outwardly so you could see it...the packing will have blow-by, just like an engine.
Ok, so I leveled the boat and checked the fluid, it was full enough to come out when I took the plug out. I also check the manual release screw and it was tight enough that I couldn't get it to tighten anymore. So Scrapper, you're talking about the 3 O-rings listed in item 2 on the diagram you sent called a O-ring kit, rebuild, right?
Yes. Of course you would want to check out the cylinder wall for any scoring. There are many other orings that you would want to replace as you go through it. Those are the orings that would cause the inner problem that you wouldn't see on the outside. I think that diagram is correct for your application. But make for sure before you were to order anything. After you know that the parts are correct for you and that they are available...then start taking it apart. Not before knowing you can get a hold of the parts. Been in that position to many times. lol. Take apart...and then not be able to get parts for a week or so. :banghead
Thanks guys.