Help with Yamaha F90 Tilt and Trim

[Steve Stinson]

I was at my son's basketball game this morning when my wife came into the gym and said she'd been trying to call me. The motor on my boat was raising up by itself and making a squealing noise. She climbed into the boat in the carport and tried to trim it back down with the switch on the throttle handle, but all it would do was continue to make the squealing noise.
I rushed home thinking I may have some burnt wiring on my hands or worse yet, a boat fire, maybe a house fire. When I got here, the motor was all the way up, no noise. I trimmed it up and down with the switch in the bow - worked fine. Walked to the back of the boat and opened the battery compartment, battery was cool to the touch, nothing burnt. Reached down and felt the trim motor which was barely warm to the touch. Climbed in the boat and tried the trim switch on the throttle handle which worked fine. Went to turn the ignition switch over and found the key in the "run" position, but the motor cranked just like it should. Went back to the bow and removed the plate where the trolling motor plug and front trim switch are. The trolling motor plug had some rain water in it, but the back of the trim switch looked dry. Again no evidence of burnt wiring.
I've seen this motor trim up on it's own once before and also fussed at Steve Taylor for trimming it up so high when we pull out of a ramp once in a while. (Steve swore he didn't trim it up that high, but I attributed it to his old age and senility). When you trim the motor all the way up on my boat, the hinges on the back pedestal seat scratch the top of the motor cowling, and there are multiple scratches up there, so evidently this has been going on for some time. Some how the trim motor is getting power and moving the motor up without anybody being near the boat.
The only other thing I would add is that I recently had to have the bow trim switch replaced because it would put the motor down, but not raise it up.

Any advice is appreciated, and thanks for reading my long - winded post.
- Steve Stinson

[lmmoore]

Interesting post, I have 2003 Yam 115 2 stroke, but i have never had this or heard of it happening. Sounds electrical for sure, which i know nothing about. Thanks for the post looking to learn something.

[ugadawg]

My guess would be a worn out spring on the trim relay. I would also think that if it was the relay or the switch it would be happening all the time, not just periodically.

[Hollywood]

I had the same issue with my Yamaha F115 and it almost burned up my trim motor, What I found was it was the trim switch on the motor had failed internal and was making contact causing the motor trim up. I would check the switch on the motor and the throttle.

[rockyg]

Turn your battery selector switch to the off position when the boat is not in use.

Don't have one you say......might want to install one.

I'll bet Hollywood is right. The trim switch on the motor most likely, but could be either.

[Steve Stinson]

I will call Big Bend Marine on Monday and see what they suggest. I believe Hollywood is correct because I am pretty sure the squealing my wife heard was the trim motor continuing to run even though the motor was trimmed all the way up.

I don't have a battery selector switch, but after my mad dash home, I disconnected the Pos. cable on the motor battery until I can get this figured out.

Thanks for the help, and I will post the investigation results when I know more.

[Flint River Pirate]

I had this happen once with a F115 Yamaha. It turns out the trim switch on the bow (next to my trolling motor) had a short circuit. I disconnected the wires because I never used that switch anyway. Never had that problem again.


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[UFBeef]

Turn your battery selector switch to the off position when the boat is not in use.

Don't have one you say......might want to install one.

I'll bet Hollywood is right. The trim switch on the motor most likely, but could be either.

This.

[Steve Stinson]

Update -
I talked with Dale today at Big Bend Marine where I purchased my boat. He believes the problem is in the front trim switch up by the trolling motor. He says they have had problems with water getting into those switches and connecting the contacts, making the motor rise. Once the switch gets warm and dries the moisture, the problem stops and everything appears to work fine. In fact, some of his customers have had this issue while underway if they took a swell over the bow.

Evidently, the switch on the front panel is not made as well as the other two Yamaha switches. So I guess I can disconnect it and live without like Flint River said above, or attempt to seal it up and keep it drier.

Thanks for all the input. My wife will be relieved to know the boat is not possessed. She was ready to call in a Catholic Priest to exorcise cast out the demons from the boat.

[Flint River Pirate]

I thought that would be the case. I'm glad they tracked it down.


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[Salty Gator]

Dale is good people, glad he's bird dogging it for you. Is a tilt trim switch up front a common thing? I don't think I've seen that before. I usually trim mine up when the tm comes out,but I've certainly scrambled to the console to try to get it up in hurry more than once

[UFBeef]

You still should have a battery switch that kills all power to your boat somewhere, only thing that should be able to run when the boat is turned "off" should be the bilge and the auto switch for the bilge, wired directly to the battery. I've never seen a tilt/trim.switch on the bow, maybe I'm misunderstanding something, not sure what the use would be?

[Jumptrout51]

Your long overdue apology is accepted.
On several occasions while fishing from the aft old folks seat, the motor would trim all the way up and smash my leg at times.
It made the seat immovable.
I figured you had a remote lanyard switch as your foot would not be near the deck switch.
There is no way to know if my thinking about your motor this weekend had anything to do with the motor raising.
After all, it was just thinking.

[dombern34]

http://www.561paranormal.com/

[Steve Stinson]

Most every bass boat I've ever been in has a tilt switch up front. It's handy when you are in real shallow water running the trolling motor. If your outboard hangs up on an oyster bar or a log, you can trim it up a little and keep fishing. I don't like to trim the motor all the way up while fishing because it's in the way of the grumpy guy fishing in the back (see Jumptrout comments above), and in a breeze the rear of the boat will swing around a lot causing constant corrections to be made with the trolling motor.

I have three options - figure out how to seal it up, disconnect it and do without, or replace it with some sort of a better made switch. After talking to Dale, I don't want to take a chance on having a swell come over my bow and causing the motor to raise. As you know, rough conditions is when you have to keep the bow high and pointing into the swells. Having to shut your motor off because it raised itself out of the water could cause you to sink the entire boat.

Thanks to all of you for the help. Sorry for the inconvenience and false accusations to Jumptrout - your legs should be healed up by now anyways.