Not Locking Into Reverse

[lawofthesea]

I have twin 2001 250 OX66 engines and one of them does not lock into reverse. When I shift into reverse and begin backing up, the engine starts tipping up and coming out of the water. Does anyone know what could be causing this? Many thanks in advance.

[boats.net]

It would be a problem in the power tilt/trim system. If it's full of fluid and tilts up and down ok then it would have to be rebuilt to solve problem.

[lawofthesea]

Thanks so much. I rebuilt the pressure relief valve, and I also redid the seals in the main piston just in case. Would have cost me essentially nothing except I cracked the housing, so had to buy that piece for $225. Oh well, cheaper than a mechanic anyday, thanks for all the help, great forum!