1987 Mercruiser 165 ATF Fluid?

[John_B]

I bought this boat but don't know a lot about it. I noticed a fluid reservoir in the back compartment that says Automatic Trans Fluid only. Can anybody tell me what it is? How to fill it? and what it controls please?

Thank you,

 

[Bondo]

Ayuh,..... That's a Bennett trim tab pump,.....

Lift off the smoke colored cover, 'n you'll find the fill plug in the top of the white tank,.....