part on lower unit of 1980's 25 hp mercury

[lowesam]

there is a cast looking circle piece on the bottom of the plate right above the prop, and i was wondering what this thing is, and what it does. just curious if anyone knows, i'm sure a picture would help, but the camera is dead at the moment and i thought someone might know off hand what it is.
thanks
sam

 

[lowesam]

i think that i have found my answer, i believe it is the sacrificial anode. if anyone knows about these on the older mercs i'd appreciate the info, as this is my first mercury.
thanks
sam

 

[bAcKpAiN]

I am not positive, but I believe they are only needed if you keep your boat moored in the water rather than trailering it. It is there to wear down and corrode without any corrosion coming to the motor itself. If you fish freshwater, and trailer your boat I wouldn't worry about it. Even if you fish the salt, I think you are ok without one so long as you rinse and flush well after use in the salt. But if you keep the boat in a slip or in the water for long periods of time that is when they are needed.

 

[crazymanme2]

bAcKpAiN is correct =D>

 

[lowesam]

thanks for the info, i was almost positive that was what it was, i saw it on the outboard i just traded for and it has a small spot broke off of it and i just wanted to make sure that it wasn't something i needed to fix or replace before i took it to the lake to run it out.
thanks again
sam

 

[bassboy1]

thanks for the info, i was almost positive that was what it was, i saw it on the outboard i just traded for and it has a small spot broke off of it and i just wanted to make sure that it wasn't something i needed to fix or replace before i took it to the lake to run it out.
thanks again
sam

On many motors, it is also the torque tab. Hence why it is adjustable, and has the ear hanging down. What that tab does is counteract the torque steer of the motor. Believe it or not, a degree or two of change in that little bitty tab will make a big difference. It is a nifty little thing to have. Take it from someone who runs a tiller operated 40 without an adjustable tab, and the nonadjustable tab is not adjusted correctly.