Mercruiser Sterndrive Anodes

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Mercruiser is known for making top of line sterndrive boat motors. There are several ways to maintain the health of your engine to ensure you spend time on the water rather than in the repair shop. One aspect of taking care of your engine is to maintain the proper functionality of your engine. One way of doing this is to protect the metals on your motor from corrosion. Corrosion is caused by the water degrading the metal on the motor. To protect your Mercruiser motor from corrosion you need to use anodes which act as the weaker metal so the anodes corrode instead of your engine. Here at iboats, we carry every anode you would need to protect your motor from corrosion. In addition to our huge product line, iboats also offers competitive pricing that is hard to match.

Cavitation Plate & Transom Anodes 34762 55989 821631/43994 43396 821629C 821630 817373 C89949 Trim Ram Anodes 806189 806190 Trim Tab Anodes 46399 31640 34127 762145 762144/76214 822777 Prop & Prop Shaft Anodes 809664 CMPNDF14UNS CM865182C 809660 806105 806188

Mercruiser Anodes How-To's

Why You Need to Check Your Anodes/Zincs

Why You Need to Check Your Anodes/Zincs if You Leave Your Boat in the Water by Matt Sellhorst (Video)

Here is a detailed video with Matt Sellhorst showing you how to change and determine if your anodes need replacing.... read more

Video Transcript

Hi everybody, today I want to talk about anodes. It’s something that you don’t really think about a lot when it comes to boating but it can cause major issues. It’s a fairly inexpensive maintenance item. Zincs or anodes, as what you hear them called. I’ll show you what happens if you don’t change them. On boats—it’s mainly for boats that are left in the water, but you should have little sections of sacrificial metal. You see this one right here, it should take up the whole section. But you can see how eaten away it is and it’s pretty much not doing anything right now. What happens is when those anodes go away, that corrosion, it starts attaching to the lower unit and you start getting growth and corrosion where it starts peeling away the paint. This one was so bad it actually ate the skeg. If you look over at this other one, it’s getting really close to doing the same thing; it’s actually eating away that metal. It can be resolved by one pulling your boat every year and cleaning your drives but also changing the anodes. I’ll show you, there’s one here on this particular boat there should be one but you can see those screws that’s almost totally exposed. You have them on the trim cylinders. You have another one here on the back. Then some of them you may even put on a plate that sends out an electrical impulse that limits your corrosion as well. On the trim tab you’ve got another one. What they do is they use them to sacrifice the metal. You can change those out for $300 - $400 on a twin engine boat and it’ll save your drive. This right now has a—I think it’s a $6,000 - $7,000 repair that needs to be done. Once this gets eaten up so bad it potentially can leak into the gear casing and cause even more mechanical issues. Now let’s go and take a look at a good one and see what those look like. All right, so here we are looking at a brand new, 2012 C-Ray. This boat’s never touched the water. If you look, you see they’ve actually added one, they’ve got one on the hub of the prop. You have another one here, look at how big that is compared to the one we just looked at. That’s what it started out on that boat probably, they make a smaller one that’s about half-size but that’s the one on your trim cylinder. You’ve got another one and then you have the full one on the trim tab. Now again, that’s what a brand new set looks like and how big they are. So you can see how much was eaten away and why once those are gone, how that corrosion can start attacking the lower unit. Now if you keep up with the anodes and you pull your boat and you clean it, you can avoid that issue. But let’s go in and take a look at one that’s kind of in the middle. All right, so here’s one that’s kind of in the middle. As you can see from the bottom, this boat is left in the water and that’s when it’s most prevalent to have the issues. You can see there’s just a little bit of corrosion starting. You can see that the skeg probably got the worst of it. This anode looks like they’ve been changed probably in the last year or so but you can see how pitted they are and they’re starting to not do their job. The recommendation is when they get 50 percent eaten up that’s the time to change it. You can see around the edge it’s starting to go away and all that corrosion there. This particular boat doesn’t have one the hub which may be a good idea, which may help protect a little bit more but it’s one of those things. If you do leave your boat in the water, don’t forget to check your anodes. Again, some of the metal is zinc. Ask your certified boat Mercruiser technician or dealer what’s going to be the best type to put on, what’s going to be the most protection based on the state of your drive. Ask if you need to put the Mercathode on which I said is the little—it looks like a button almost, that can be mounted on the back of your boat to send out an impulse to limit that corrosion. For a couple hundred dollars maintenance every year, you can save yourself major problems and also increase the resale value of your boat when you go to trade it in or sell it.

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