Motor doesn't stay up while trimmed.

[CoachKWJ]

I have a 2005 70 hp that has performed flawlessly until last fall. I was on the trolling motor in shallow water and all of the sudden the boat wouldn't move. I looked back and the motor had slowly dropped down in the course of a couple hours. I checked and filled the reservoir and it seemed to work the next couple times out. I could not see any signs of leakage. I put the boat away and soaked the seals with fluid. First few times out this year all was good. Then all of the sudden, same issue. Motor slowly drops down. Still no sign of leaks and reservoir full and cycled up and down several times with transom straight. Don't want to have to monkey with replacing the seals if I don't have to. Shouldn't there be some signs of a leak? Or could I be overlooking something.

[Charlie206]

It is not the seals that you can see. It is a likely a check valve within the hydraulic unit with a small piece of trash keeping it from seating. You can sometimes take all the fluid out that you can get out, put in some new and cycle it a lot and it may dislodge the trash and if you get lucky, fix it. Also, make sure the screw in the bracket that controls manual release of the trim is closed tight. If it has loosened, that will cause it.

[jethro1]

Yes, it is probably an internal seal leaking or check valve. But definitely make sure the release valve is goodentite.

When the motor fails to stay up on its own, do you trim it up and then stop? You might try trimming it up just beyond where you want it to be and then use the down button just a tad. This sometimes can help to force a valve to seat that otherwise won't. It is free to try, so give it a whirl and let us know what happens.

[Wild Heethen]

Yes, it is probably an internal seal leaking or check valve. But definitely make sure the release valve is goodentite.

When the motor fails to stay up on its own, do you trim it up and then stop? You might try trimming it up just beyond where you want it to be and then use the down button just a tad. This sometimes can help to force a valve to seat that otherwise won't. It is free to try, so give it a whirl and let us know what happens.

Thanks Jethro1. My 2002 200hp HPDI is doing this exact same thing. Will try it.

[woppercatcher]

I have a 2012 HPDI 175. I had the same issue as this along with 3 other issues of the motor not trimming up or down properly while under warranty. 1st time to the dealer they said they replaced the seals but didn't find a leak. That worked for about 8 months. Each time after that they would say they couldn't find a leak they would drain, bleed and refill. Again, six months later it would act up again. Then the weird thing happened. I told my dealer I was fed up and they said I needed to call Yamaha and tell them I was fed up and the dealer couldn't find anything wrong. Called Yamaha and gave them the history. Yamaha said they would have to call the dealer and have then have the dealer call Yamaha to ask if they could replace the unit. What? Anyway, in the end the unit was replaced and no problems since. Good luck!

[Shiner]

Down below the trim there is a screw you can tighten to keep motor from dropping down. Mine was doing the same thing and it was loose. Check that first!

[CoachKWJ]

Been away a while. Will definitely try the up then just a bit down. Can't hurt, right? Does sound like a valve internally. Screw is tight. First thing I checked. If it is a valve, is it a DIY project or does a pro need to attack it? Don't have alot of $$$ to spend right now. Major nuisance but not a major problem. Motor runs like new. Hope its just a simple fix but I don't think so.

[CoachKWJ]

Yes, it is probably an internal seal leaking or check valve. But definitely make sure the release valve is goodentite.

When the motor fails to stay up on its own, do you trim it up and then stop? You might try trimming it up just beyond where you want it to be and then use the down button just a tad. This sometimes can help to force a valve to seat that otherwise won't. It is free to try, so give it a whirl and let us know what happens.

Definitely going to give this a try next time out. Thanks Jethro1!

[CoachKWJ]

O.K. I've tried everything and no luck. I want to try draining the fluid and re-filling the reservoir. Is there a drain hole or do you try to suck as much out as you can through the fill hole? Not sure what else to try short of tearing everything apart or taking it in to have repaired, which I really don't want to do.

[Chisco]

Had the same problem....you have to use a syringe to pull as much fluid out as possible. Refill with trim fluid. I had to drain and refill twice before it finally worked. Be sure the screw (relief valve) at side of trim is tight as others have said. It's not the fill screw.

[CoachKWJ]

Thanks Comb. Maybe there is hope after all. Got the fluid, now just need to get the old stuff out. Did you cycle the motor up and down after draining and filling the first time and it still didn't work?

[Chisco]

Thanks Comb. Maybe there is hope after all. Got the fluid, now just need to get the old stuff out. Did you cycle the motor up and down after draining and filling the first time and it still didn't work?

yes....cycled it up and down. Seemed to work for a little while (a couple hours) but then slowly dropped down again. Drained again as best I could and it now holds...been a few weeks now with no problems. I actually removed one of the trim caps to where I could get to the fluid better.