Yamaha 300hpdi trim and tilt issue

[runaway77]

Hello everyone,
While on plane port engine tilts out of the water. I disconnected manual trim on outboard, but it still occurs. Any ideas why this is happening?

[boscoe99]

What is meant by disconnecting the manual trim? How was this done? Exactly what was done?

[runaway77]

the wires were removed from the manual switch on the cowling, also when the boat is docked and the motor is trimmed up about 3/4 of the way, with some force i am able manually to pull the motor to full tilt position.

[TownsendsFJR1300]

Sounds like two issues.

First re tilting up on its own. That sounds like the helm trim switch is sticking in the up position. I would spray some liquid wrench in there, the best you can get in there. Work the switch up and down.. You may have to access the switch itself if not successful from the outside.

Worse case scenario, pull the switch and test, it's likely simply sticking (inside contacts can be sticking) and if won't loosen up to normal, need replacement...


Re pulling the engine up. If the SAFETY RELEASE screw (large flat head screw-located looking thru one side of the transom brackets) is not snug, you'll be able to move the engine. When its loose, it generally falls down with gravity, so that may not be the fix...

[99yam40]

the wires were removed from the manual switch on the cowling, also when the boat is docked and the motor is trimmed up about 3/4 of the way, with some force i am able manually to pull the motor to full tilt position.

If you call that the manual switch, where is the automatic switch located?

My guess would be air in system if you can move by hand

[boscoe99]

If you call that the manual switch, where is the automatic switch located?

It is right next to the semi-automatic switch you dummy

My guess would be air in system if you can move by hand

What prompts someone to manually pull a motor up when it has been powered up the 3/4ths position?

I am still trying to understand a motor tilting itself out of the water when the boat is on plane. When the motor is doing all that it can to push itself to the full down position. Hmmm.

[99yam40]

Sounds like two issues.

First re tilting up on its own. That sounds like the helm trim switch is sticking in the up position. I would spray some liquid wrench in there, the best you can get in there. Work the switch up and down.. You may have to access the switch itself if not successful from the outside.

Worse case scenario, pull the switch and test, it's likely simply sticking (inside contacts can be sticking) and if won't loosen up to normal, need replacement...

might also be in the wiring not the switch itself
something has be getting power the the relay for it to energize to turn the T&T motor on.

and as far as the tilting by hand, it is hard to believe one person could lift up a 300 motor against the safety valves

[TownsendsFJR1300]

might also be in the wiring not the switch itself
something has be getting power the the relay for it to energize to turn the T&T motor on.

and as far as the tilting by hand, it is hard to believe one person could lift up a 300 motor against the safety valves

Agreed but its (switch) the most likely to act up.

My engine mounted, T&T switch, (about a month ago), wouldn't go down on occasion. Helm worked fine. Squirted a bunch of liquid wrench in the switch (as best as possible), worked the switch up and down, fixed!

Just a crappy connection with age/time.

[99yam40]

I said might be

a stuck switch should be easy to find, but since it does not do it all of the time it will be harder to find.
strange how he does not say the motor tilts up by itself at any other time except on plane.
could it have something to do with the fact he can tilt it up by hand?

maybe that motor was not running as hard as the other and the force of water is pushing it up, not the T&T motor running and lifting it

[RayBersch]

maybe that motor was not running as hard as the other and the force of water is pushing it up, not the T&T motor running and lifting it

That could be easily tested by running on plane using only the offending engine (or at least at high rpm's) to see what happens. But I sincerely doubt that type of scenario would result in the lagging engine being pushed up.

If the trim/tilt works smoothly through its normal full cycle then I suspect an electrical issue, and I suspect the OP has the same idea and that is what made him disconnect the engine mounted switch. To test for a hydraulic issue he could power up the offending engine in reverse - THAT could be exciting! But low fluid level or air in the system should be noted by other complaints like slow or ****y operation or the slow falling of the engine when tilted all the way up.

[TownsendsFJR1300]

Under power, that engine is NOT lifting up, its PUSHING DOWN..

now, stick it in reverse, then we'll see if it raises!!

[99yam40]

Under power, that engine is NOT lifting up, its PUSHING DOWN..

now, stick it in reverse, then we'll see if it raises!!

If it is not turning at the same high RPM/speed or not running at all it is a drag.

I am just guessing as to why it raises by itself when on plan and he can lift it by hand from 3/4 up to full when out of the water.
these are the only facts he has shared with us so far.

[TownsendsFJR1300]

My interpretation is that the T&T is lifting it UP, on its own-(hydraulically/electrically). IE, the switch sticking up at the helm (or a short as you mentioned)

Some more info from the Op to clarify would be nice....

[99yam40]

it has more than one motor if he calls that one with the problem the port one.
Only he knows how many motors he has on his boat

[TownsendsFJR1300]

it has more than one motor if he calls that one with the problem the port one.
Only he knows how many motors he has on his boat

Naw, your right..