Trim and tilt help

**Punteh** · 10-01-2023, 09:31 PM

I have a case of sagging trim on my 91 Yamaha 200. The trim and tilt still works but when cruising I'm not able to trim the engine up past a certain point without it dropping back down, and also if I trim the engine up when the boat is parked the engine will slowly and eventually trim down. There are no leaking seals or lines or anything so I'm assuming it's an internal seal issue. The unit has never been rebuilt.

I'm wondering what the best solution is. Is it simple enough to take it apart myself and replace all of the seals? I've watched a video and it seems straight forward enough. I am mechanically inclined but I know videos online aren't always the best sources of information.

My second option would be to take the trim and tilt unit out and sending it off to be rebuilt. The only thing I'm not sure about for going this route is if it's possible or how difficult it might be to remove the unit with the motor still mounted on the boat. Taking the motor off the boat isn't an option.

Any recommendations or advice would be greatly appreciated.

**David - WI** · 10-01-2023, 09:43 PM

I would first check if there is a manual "bypass" valve like on a Mercury... if the valve isn't closed tightly it will leak down (don't know anything about Yamaha).

**Punteh** · 10-01-2023, 10:03 PM

There is a manual bypass valve. It is closed tightly. Good thought though, I will check it too make sure it is tight but I'm pretty sure that's not the problem.

**skialot2** · 10-02-2023, 12:13 AM

On the Mercury's, that bypass valve has 3 O-rings. Those O-rings get hard and no longer seal and you get leak down. If you change those O-rings lots of times that will fix the leak down. Tilt the motor all the way up and support it. Take the e clip off the valve so you can unscrew it through the mounting bracket. Oil will come out with a little pressure. Change the 3 little O-rings and reinstall it. Refill the fluid. You might get lucky. The engine does have to come off the boat to completely remove the power trim unit.

**Punteh** · 10-02-2023, 09:33 PM

Originally Posted by skialot2

On the Mercury's, that bypass valve has 3 O-rings. Those O-rings get hard and no longer seal and you get leak down. If you change those O-rings lots of times that will fix the leak down. Tilt the motor all the way up and support it. Take the e clip off the valve so you can unscrew it through the mounting bracket. Oil will come out with a little pressure. Change the 3 little O-rings and reinstall it. Refill the fluid. You might get lucky. The engine does have to come off the boat to completely remove the power trim unit.

I will look into the bypass valve o-rings. Thank you