outboard replacement

[abbotm5]

Im replacing my 90hp outboard with a 120. The mount is like an upside down U. The horizontal part of the 90 did not sit on the hull. It was about 1/4 above the fiberglass so its supported vertically solely by the mounting bolts. Is this normal? Its seems like it would be better for support to sit on the hull rather than above it. I have to drill new holes to mount the new motor so I wanted to figure out how it should be done.

 

[Chris1956]

Re: outboard replacement

You want to mount the OB such that the antiventilation plate is even with the botom of the hull. If the transom mount is above the top of the transom that is fine and very common. I just raised my 150 Johnny all the way up. It is now 2" above the top of the transom.

BTW - The four 1/2" mounting bolts are overkill in strength.

 

[Silvertip]

Re: outboard replacement

Engines have multiple mounting holes to allow adjusting the motor up or down since transoms vary significantly. Without adjustability, performance could not be optimized unless one drilled a bunch of holes in the boat to experiment with engine height adjustments. Yes -- it does make a difference how high the engine is mounted.