zinc anodes

[omceed]

On my 1993 200 Ocean runner there seems to be 2 anodes.
They are 90% of original size.
Do these waste away or just loose there effectiveness after a certain amount of time?
I run mostly in brackish water.
Is there a rec. change interval or signs of needing replacement?

Thanks for you responses.

 

[Turin]

Re: zinc anodes

Thy should be replaced as thy change color I thougt

 

[ezeke]

Re: zinc anodes

They can fool you. If they don't have electrical continuity with the motor, they can look fine for years, doing nothing while gavanic corrosion eats away at your motor. If they turn white, they are not doing anything either, because the white is an oxide preventing continuity with the water.

The best thing to do is remove them periodically, file or sand them down to shiny metal, brush the bolts and bolt holes to shiny metal, then use an ohmmeter to check for continuity. You should have one inside the gearcase, one recessed above the a/v plate, and one at the base of each transom bracket.

 

[cadriver]

Re: zinc anodes

You should have one inside the gearcase, one recessed above the a/v plate, and one at the base of each transom bracket.

Is the one inside the gearcase really necessary or can this anode be install somewhere else outside?

 

[ezeke]

Re: zinc anodes

I don't plan on ever tearing down a gearcase again myself. I added some extra anodes on the transom brackets, though.

 

[omceed]

Re: zinc anodes

Thanks Ezeke, mine are kind of white-ish (spotty).I will file down and do as suggested to the bolt and holes.

Will they shrink as a matter of normal wear also?

Thanks again.