2012 Yamaha 225 Dropping

[Jonah272]

Thanks everyone.

Boscoe99, thanks for the input about the tilt locks. I am going to use the tilt locks for now, and continue to look into why the one outboard is dropping.

Ausnoelm, I don't think it could be a faulty switch. I've been working on the boat before while the outboard slowly dropped, and didn't hear any accidental operation of the pump.

Zenoahphobic, I like your insight on potential play in the components. However, the outboard does seem to drop lower and lower the longer I let it go. After 5 days away, the prop was nearly in the water. I might try to let it go even longer, but I don't like letting so much of the skeg sit in the water for days on end. I suspect that it would stop dropping once it got to the point that the fine-tune trim came into play. Because after all, that trim pump seems to hold its position just fine when the boat is underway.

Rodbolt, I suppose you may be right; I just don't see any other signs of a leak. Also, I would suspect that if I had a leak, the outboard wouldn't be able to trim all the way up to begin with, right? Correct me if I'm wrong there.

As for next steps, I will run a test to make sure that the outboard is holding its position when the boat is underway. I suspect it will, since in that position it's being held in position by a different trim system, right? Those are the two shorter pistons that do not engage until the outboard is about 50% down, right?

[TownsendsFJR1300]

Rodbolt, I suppose you may be right; I just don't see any other signs of a leak. Also, I would suspect that if I had a leak, the outboard wouldn't be able to trim all the way up to begin with, right? Correct me if I'm wrong there.

As for next steps, I will run a test to make sure that the outboard is holding its position when the boat is underway. I suspect it will, since in that position it's being held in position by a different trim system, right? Those are the two shorter pistons that do not engage until the outboard is about 50% down, right?

The shorter rams are for the trim, the single longer ram-the tilt.

It's all obviously in the same unit but as noted, somethings leaking internally in the "tilt" side of things over time.

http://www.boats.net/parts/search/Ya...201/parts.html

.

[boscoe99]

The tilt piston has seals on it to prevent hydraulic fluid from getting from one side of the piston to the other side. With the motor tilted up gravity is trying to bring the motor down. The tilt piston is being forced downward. Hydraulic fluid on the bottom side of the piston is preventing this from happening since liquids are virtually incompressible. If the seals leak then over time the piston can move downwards into the cylinder. Hydraulic fluid bleeds over time from the high pressure side to the low pressure side. Maybe the diagram below will help to understand it better. The yellow area is where seals and check valves are located. Any one of which can leak.

[Jonah272]

Thanks again everyone. I will use the tilt locks for now, until I find a mechanic I can both trust and afford down here in Nassau, Bahamas.

[walleye1]

Send me a two way ticket for a week.

[dray0151]

Send me a two way ticket for a week.

I thought you were headed to Mexico????

[walleye1]

Feb 2nd for only a week, Huatulco Mexico.

[walleye1]

it's warming up,, it's -6 now.