Aquamatic Exhaust Flappers

[jeffnick]

My 250 has an obvious flapper that covers the exhaust cup behind the propeller - to keep water out of the exhaust system while backing down? Is there a similar flapper somewhere on the 280?

 

[RicardoMarine]

A few 280 drives were equipped with the exhaust outlet located flapper. These were production models only.
The rest of the them used the more restrictive bellows flapper.

A 290 or later s/p or DP drive exhaust outlet flapper can be retro-fit to the 280.
There is a hump or bump that must be ground down, and the flapper may require a tad bit of material cut from the width at the center.
Otherwise, it does work, and is much less restrictive than the exhaust bellows flapper.