Slight out trimming at WOT slammed outdrive into Trailer mode

[JonBoat55]

New boater here. Recently got a 1999 Regal 1800 with a 3.0 Merc stern drive. I haven’t posted here yet because every question or issue I’ve run into has been asked and answer here...this forum is excellent.

Ran into something yesterday on the water that I can’t find an answer to though, so here it goes...
Was running the boat at WOT after getting to plan quickly with the outdrive trimmed all the way in. I eased off the throttle once on plane and started to slowly trim out to get some more speed. I quickly started feeling the prop lose its bite and rapidly lost speed and RPMs went high. Put it in idle and looked behind me and the outdrive was trimmed to the TRAILER position.
I shut the motor off and tried to trim back down, no response. I could hear the trim pump chugging for a couple seconds every 30 seconds. It did this for about 5 minutes. Once it stopped, I had trim control back. Fired the motor and carefully went back to the dock.

I didn’t hit anything, deep clear water. It almost seemed that the drive got grabbed and slammed up by the flow under the boat and the trim pump was working to build lost pressure back up. I’m not sure what would have caused this.
Any ideas that won’t make me smack my forehead?
Thanks guys

 

[JonBoat55]

New boater here. Recently got a 1999 Regal 1800 with a 3.0 Merc stern drive. I haven’t posted here yet because every question or issue I’ve run into has been asked and answer here...this forum is excellent.

Ran into something yesterday on the water that I can’t find an answer to though, so here it goes...
Was running the boat at WOT after getting to plan quickly with the outdrive trimmed all the way in. I eased off the throttle once on plane and started to slowly trim out to get some more speed. I quickly started feeling the prop lose its bite and rapidly lost speed and RPMs went high. Put it in idle and looked behind me and the outdrive was trimmed to the TRAILER position.
I shut the motor off and tried to trim back down, no response. I could hear the trim pump chugging for a couple seconds every 30 seconds. It did this for about 5 minutes. Once it stopped, I had trim control back. Fired the motor and carefully went back to the dock.

I didn’t hit anything, deep clear water. It almost seemed that the drive got grabbed and slammed up by the flow under the boat and the trim pump was working to build lost pressure back up. I’m not sure what would have caused this.
Any ideas that won’t make me smack my forehead?
Thanks guys

 

[Bondo]

Ayuh,..... Welcome Aboard,..... My Guess is, the trim up solenoid got stuck, "On" for some reason,.....

 

[Scott Danforth]

did you check to see if you have oil in your reservoir?

 

[JonBoat55]

It seemed to happen very rapidly, like the drive was forced very quickly (less then a sec or two). I dont think it was slowly trimming until I noticed. Gauge went from trimmed down to all the way up into trailer trim just as quick......?

 

[JonBoat55]

Looks like I posted twice, sorry about that.....

Scott, I did not check yet. Is that something along the lines of the trim losing pressure due to not enough oil?

 

[GA_Boater]

Merged both threads since both had replies.

Test the Trim Limit switch adjustment and operation. It should have stopped the drive upward movement.

 

[Bondo]

It seemed to happen very rapidly, like the drive was forced very quickly (less then a sec or two). I dont think it was slowly trimming until I noticed. Gauge went from trimmed down to all the way up into trailer trim just as quick......?

Ayuh,..... I donno how that could happen, unless in reverse, 'n no oil in the trim system,.....

You say there was no impact,..??.....

 

[alldodge]

My trim switch on the throttle handle starter sticking without warning a few years ago. Replaced the switch and all good now. Your issue sounds like waht happened to me other then the neutral and shut down. Also my trim limit stopped it from going all the way

 

[tpenfield]

I've had the trim button get stuck and trimmed up to high.

One thing to look at is that . . . the trim circuit (button) should not be able to raise the outdrive beyond the trim limit. sometimes folks bypass the trim limit switch (that is on the outdrive) by shorting the wires together. This along with a stuck switch or solenoid would cause the issue you experienced.

Get back to basics and check everything about the trim and tilt operation. Refer to the manual for the Alpha drive as needed.

 

[JonBoat55]

I will check the Alpha manuel and read up on the trim system in general. The trim limiting switch does currently work, will let me lift the prop only so far, then have to switch to the trailer button to lift the rest of the way.

Any experience with having no trim control while the hydraulic pump (which im guessing) re-calibrated itself over the course of 2-3 minutes? I was dead in the water while i was waiting to get trim control back, prop was almost fully out of the water.

 

[Bondo]

Any experience with having no trim control while the hydraulic pump (which im guessing) re-calibrated itself over the course of 2-3 minutes?

Ayuh,..... The pump doesn't recalibrate, it's a simple pump, controlled by the switches,.....

If it went up beyond the trim limit, there's wires shortin' out somewhere,.....

 

[alldodge]

There is no calibration for your trim system other then the trim limit adjustment part. Best guess is the solenoid got stuck as Bondo mentioned in post 3, if other things didn't happen like previously posted

 

[wahlejim]

Also check your trim position sensor and trim limit switch on the outdrive. If you are judging your trim level based on the gauge, if those two are not tight you may have not been trimmed fully down even though the gauge said you were. It would also allow you to trim all the way up with no limit "Just as quick", if the position sensor was loose, it could have turned in the water and shot the gauge straight up.

Since you were underway, oil us unlikely the problem as you would have had issues trimming up, which you clearly didn't have. It is worth checking, but it is much more likely something electrical.

 

[JASinIL2006]

Is it possible a previous owner jumpered the trim system to bypass the trim limit switch? That would make the trim up switch function exactly like the trailer switch.

People often do that if that switch goes bad and they don't want to pull apart the back end of the boat to replace it correctly.

 

[QBhoy]

Hi. The forces and thrust caused by the drive when running at speed mean that it couldn’t have naturally worked it’s way up. A considerable force is needed to overcome this.
Sorry for being obvious but the trim button on boats of this era will bring the drive all the way up if you hold in the button to it’s secondry action beyond the normal trim limit. Especially and easier if the trim limit switch is gone.

 

[JonBoat55]

Was able to duplicate the problem in the driveway...stuck solenoid while triming out (about one in ten times to make it happen).
Thanks for all the info fellas.
Does this mean a new solenoid is needed? Or is there a fix?

 

[alldodge]

If it was the solenoid sticking then yes, otherwise its the handle switch