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Mercury tilt and trim will trim out under load

P

prodjay

New member
My 1999 Mercury 200 Blue water EFI tilt and trim will not trim out when under a load.

It seems to work fine as long as the motor is in neutral or not running at all. It do not make any unusual noises and go up and down very smooth. I did check the fluid level and the relief screw and it all looked fine.

Any ideas would be great!!!
 
Like many hydraulic systems your trim ram is a tube with a piston which is moved by fluid to go up, the fluid is allowed to flow out when you want to go down.

There is valves and seals "internally" that allow the flow or prevent the flow of the fluid as required.

While you are in neutral the motor is not putting any "force" on itself or the boat, you hit the "trim up" and it trims up.

Now while under way your trim is "fighting" against the motor - the prop is (essentially) trying to crawl under the boat and you are trying to "lever" the whole motor up with the trim.

It "should" be able to do it, just with more effort (on the part of the trim motor). Since you note your fluid levels look ok, that indicates that it's not leaking "externally" but it could be leaking "internally" - if your fluid is "blowing by" a seal or valve "inside" the ram or reservoir area itself, it is not building enough pressure to overcome the downward pressure being put on the unit by the motor (under way) and trim the motor up.

So, babbled on a bit, but I "suspect" that you have an internal seal issue.
 
Yes, it (measures) the degree to trim and sends that (information) up to the trim gauge on the dash (if so equipped).

Whether it's working or not it will have no effect on the trim function itself, just won't display it properly on the gauge if it's bad...
 
faztbullet said:
If the 2 small trim rams are extended do they retract went load applied???
Click to expand...

I'm not sure, it is always in the water when I have been running any test on the trim.

If I had to guess, I would say that the 2 small rams stay out when the load is applied.

I can say that when I loaded it back on the trailer both the small rams were still out.
 
faztbullet said:
Ok good...problem is most likely the impact valve in big tilt cylinder[/QUOTE

Thanks, when I take it apart will the impact valve show a bad place, in other words can I see that it is broke?

Where is a good place to get one and what information will I need to order one?
Click to expand...
 
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