F300 Anodes....

[oldmako69]

New to me set of 2014 F300s.

Today I reinstalled the lower units with new water pumps and lube. I then changed the plugs and pulled one valve cover to check a cylinder head anode.

Unfortunately, two of the zincs are under the valve cover. The anode has a nice fat gasket, but if that thing ever leaks, you'll have coolant leaking directly into the oil system. Now, I don't know that much about these engines at this point since I just started wrenching on them. But this strikes me as problematical. The boat is new to me and I just wanted to see what kind of shape they were in. Fortunately, they appear new with only a bit of growth on them. So, I reinstalled it.

I guess what I'm asking is, HOW do you ensure that when you replace an anode that it's not going to leak for the next hundred hours? I did not replace it since I didn't have spares.

Is cooling water flow relatively low pressure?

[99yam40]

what does the Yamaha service manual have to say about the servicing /replacing of those?
I would follow those recommendations

[oldmako69]

I can't find a peep about them, only the exhaust anodes. I can find them in the diagram but no real info. After sleeping on it, I'd probably feel better if I had installed a new grommet but I didn't have one. The old one was in great shape so I felt OK reinstalling it...BUT...the are accessed under the valve cover. So if it were to leak that would be horrid.

[boscoe99]

If Japanese fellow install anode and no leaky why not Amelican fellow install anode and no leaky?

Yes, cooling water pressure in Yamaha not very gleat.

[oldmako69]

Only because I resued the grommet and if they were to leak, they'd leak in a very bad spot. And you likely wouldn't even know it till the next time you pulled the dipstick.

These zincs and their holders are identical to the F225s. Probably exactly the same part numbers. Since the boat is new to me (but has 800 hours), I wanted to know what kind of shape they were in. I don't believe they've lost any real mass. They appear nearly new in shape, they just have a little marine snot on them.

On the 225s you simply popped a plastic cover to expose the coils, plugs, and anodes. Easy. They could leak all day and wouldn't cause any real harm. On the 300s you need to remove both valve covers which is quite a bit more involved.

[boscoe99]

Might want to monitor the oil condition more frequently for a short while after disturbing the anode.

[boscoe99]

After changing the oil in my car I check for oil spots for several days. Same with my replaced bathroom faucets. Being paranoid of leaks I check often.