Yamaha Power trim issue

[Action]

My 96 Yamaha 90hp has had this problem for a while now. Once the boat is on plane and you trim up, the trim seems to start falling back down on it's own, so you keep having to put the trim back up? As I said it falls very slowly but it does happen. There aren't any leaks, but I am thinking it has to do something with the piston/cylinder that drives the engine up and down? Maybe a seal gone inside that piston or something?

 

[markernineteen]

Re: Yamaha Power trim issue

Hi Action , I had the very same problem with my 2000 90hp yamaha , Rodbolt told me of several possible problems .So I disassembled the unit but could'nt determine the exact problem so I replaced all the seals and o-rings in the unit.
And it works like new . [ Thanks again Rodbolt ] But I don't know if I would do
the job again myself if I could find a pro that I trusted . MARKERNINETEEN

 

[BaileysBoat]

Re: Yamaha Power trim issue

Might be the manual valve not seated or leaking o ring on the valve.

Easy to check and cheap fix. I would look at that first.

 

[Action]

Re: Yamaha Power trim issue

Ok perfect, thanks I will have a look at it before I throw her in for the spring!