Looking at my 90 hp yamaha and the service manual, I find that I may
be low on hydraulic fluid. I have looked all over the manual and
cannot find what fluid to use although looking on the web I do find
that Yamaha sells a fluid just for this purpose. The manual says to
use ATF Dexron II to lube seals on it and many people say you can use
Dexron II.
If stuck in the "up" position, one can use a release valve on the
starboard side recessed in a hole with a screwdriver slot to release
the hydraulic pressure keeping it up. Then, you prob have just enough
hydraulic pressure for trim and tilt and it will go all the way back
up very slowly.