Yanmar 4BY2-150

Gunner065

Well-known member
Joined
May 21, 2020
Messages
108
Fluid Motion Model
C-26
Hull Identification Number
FMLR2516B010
Vessel Name
Off Watch
MMSI Number
316018278
Good day all,

I'm a fairly new owner of a 2010 R25 SC and as I was completing my pre-lay up maintenance last month, I replaced the upper engine anode but was unsure how to locate the lower anode.

If anyone has a picture of its location, I would greatly appreciate.

Stay safe and have a happy Holiday
 
I don't have a picture handy but the lower anode is on the end of the after cooler, the same end as the heat exchanger, just below it. Look at your aft, starboard side, engine mount then look up a little at the after cooler, it is right there. I find the easiest way to get to it is with a wrench with a curve in it.
 
The lower anode will deteriorate faster than the upper one as it is always in water. I change the lower one about every 3 months. Send me a PM with your email address and I can send you the service and parts manual.
 
Brian B":3hyia17d said:
The lower anode will deteriorate faster than the upper one as it is always in water. I change the lower one about every 3 months. Send me a PM with your email address and I can send you the service and parts manual.

Thanks for the offer Brian B, I was provided the service and parts manual by my local Yanmar dealer. I did look at it before posting here, but just wanted to make sure that I got the right item.
 
On the replacement engine zincs I just put a swath of red fingernail polish on the top of the bolt head before installing to make it obvious where they are located.
 
Thanks all for the assistance.

Might be a stupid question, am I right to believe that when you remove the lower anode, the cooler will empty itself of water? Once you start the engine, the cooler will refill itself?

Another question: when you change the impeller (which I will complete early next year), do you have to purge water from the raw side of cooler first?
 
Gunner065":15hy7v8z said:
Thanks all for the assistance.

Might be a stupid question, am I right to believe that when you remove the lower anode, the cooler will empty itself of water? Once you start the engine, the cooler will refill itself?
Yes it will empty and refill.

Another question: when you change the impeller (which I will complete early next year), do you have to purge water from the raw side of cooler first?
You do not have to empty the cooler first. The impeller is a challenge on these boats. I enlarged the cabin step opening for better access (pics in my album). Lot of older posts with tips on making the job easier.
 
If you intend to keep the boat for any length of time Brian’s comment is apropos. There are multiple advantages to better engine access, belt replacement, impeller, bilge pump, cleaning, fuel tank access-

My solution was replacing step as a unit.

gallery2.php?g2_itemId=35195&g2_page=4
 
As I mentioned earlier, I mark the heads of my engine zincs with red polish for easy ID. Doesn’t make getting them out and new ones in any easier though!
gallery2.php?g2_itemId=77018
 
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