Plastic where zinc goes.

[corytha]

1989 Sea Ray 16 ft. Have a mercruiser 3.0 alpha 1 outdrive. I bought a zinc kit. The place where I put the square zinc directly underneath the hydraulics for the tilt lift have a plastic piece that is connected with a wire. I cannot put the zinc there because the piece is. Can I cut it off?

 

[alldodge]

Welcome
Don't cut it off, that is the Mercathode and is more important then the zinc. If the boat stays in the water and is connected to shore power then you need zincs are needed if your in salt water, otherwise need different type depending on kind of water.

 

[corytha]

Welcome
Don't cut it off, that is the Mercathode and is more important then the zinc. If the boat stays in the water and is connected to shore power then you need zincs are needed if your in salt water, otherwise need different type depending on kind of water.

Thank you much. I'm a new owner to this kind of motor. I will only replace the zinc above the prop now. My boating area is South Florida so I'm brackish and saltwater.

 

[Scott06]

Thank you much. I'm a new owner to this kind of motor. I will only replace the zinc above the prop now. My boating area is South Florida so I'm brackish and saltwater.

Make sure you get the correct annodes (zincs) for the water you are in.

Magnesium for fresh water
Aluminum salt, brackish or fresh - I think what merc uses as OEM
Zinc for salt only

Personally I found less corrosion using OEM Merc Magnesium in fresh water vs aftermarket magnesium ones

 

[corytha]

Yes I got the aluminum for the salt water.

 

[Chris1956]

Keep the outdrive painted, or it is nearly the same metal as your anodes. If you use antifouling paint, make sure the ourdrive is well primed, before applying it, as the copper or tin in the A-F paint also adds to galvanic corrosion on aluminum.

Stainless steel parts on the outdrive also contribute to galvanic corrosion. So, if you run a stainless steel prop, Merc makes an anode that screws onto the propshaft.

Check anodes at least once/season. On my Mercruiser with the MerCathode system, I usually needed two sets of anodes for the season.

 

[corytha]

Keep the outdrive painted, or it is nearly the same metal as your anodes. If you use antifouling paint, make sure the ourdrive is well primed, before applying it, as the copper or tin in the A-F paint also adds to galvanic corrosion on aluminum.

Stainless steel parts on the outdrive also contribute to galvanic corrosion. So, if you run a stainless steel prop, Merc makes an anode that screws onto the propshaft.

Check anodes at least once/season. On my Mercruiser with the MerCathode system, I usually needed two sets of anodes for the season.

Thank you for the information. The motor was service 3 weeks ago. I am a weekend boater. Should I change the impeller yearly? I heard alpha one is hard on the impellers. I fresh water clean after every time i am in the water.

 

[Scott06]

Thank you for the information. The motor was service 3 weeks ago. I am a weekend boater. Should I change the impeller yearly? I heard alpha one is hard on the impellers. I fresh water clean after every time i am in the water.

Depends on a couple things -

I got 3-6 years out of my gen one impellers. This is freshwater northern lake so 30-40 hrs annually.

I found the OEM merc ones lasted 2x the sierra ones. Had the boat (1991) for 20 years and did 3 or 4 changes at most. Best bet is to go a season or two and open it and inspect if in good shape extend the interval. I found hot idle the temp would creep up from 145 or 150 to close to 160 when impeller was getting to the end of its life.

 

[Chris1956]

If you trailer your boat after each use, most of what I posted is unnecessary. Anodes will last years, or forever. No antifouling paint is required. Paint on the outdrive is simply for ascetic purposes.

Flushing the running engine with freshwater is a real good idea. Hose off the block every few weeks as well.

You should get 3 years out of an impeller, if you do not suck up sand or run her dry. When you do replace it, check the stainless steel cup for scratches and the plastic base for melting. Replace as necessary. IMO, you also want to replace the wearplate and 2 gaskets, when you replace the impeller.

 

[corytha]

Depends on a couple things -

I got 3-6 years out of my gen one impellers. This is freshwater northern lake so 30-40 hrs annually.

I found the OEM merc ones lasted 2x the sierra ones. Had the boat (1991) for 20 years and did 3 or 4 changes at most. Best bet is to go a season or two and open it and inspect if in good shape extend the interval. I found hot idle the temp would creep up from 145 or 150 to close to 160 when impeller was getting to the end of its life.

Thanks. Its at 135 when in water all day. I will keep that in mind. Thanks again. Mine in 1989.