Heat exchanger flush

[LET IT BE]

A local Yanmar dealer told me about a similar R29 to mine having cooling problems as a result of a lot of build up of "crud" in the sea water side of the heat exchangers. My boat is a 2013 with a Yanmar 6BY 260.
I have read about occasional flushing the system with a product such as Barnacle Buster or rydlyme.
If this is a procedure endorsed by the factory, what is the best way to do this?

I have seen videos of flushing that involve removing the impeller and pumping fluid in a circuit around the system for a few hours and then replacing the impeller. Due to the difficulty of access to the impeller I would prefer an easier way.

I have come up with an idea to do this but don't know if my theory would work, or worse, cause damage to the engine.
If I were to remove the two engine anodes in the heat exchanger end caps and put in adapters to attach to hose pipes and used a pump to circulate the flushing agent from a 5 Gallon pail, would this work? Is there a danger of any fluid entering the exhaust elbow and being lost through the muffler or worse getting into one or more cylinders because the engine would not be running during this type of flushing.
Any thoughts/suggestions welcome!

 

[Brian B]

Occasionally I use CRC Salt Terminator in my Yanmar. It does not harm rubber components so it’s safe for the impeller. About 1200 hours without an overheating issue.
As far as your flushing idea I would run that by a Yanmar tech, the risks are greater than the rewards.

 

[Capt’nKarl]

When using Barnacle Buster it’s not just a flush. The solution needs to “ pickle” for 3-4 hours inside the raw water cooling system. This time allows the solution to break up any accumulation of calcium,etc. I pickled my system last year although I didn’t have any problems and was amazed at what flushed out. I’m not sure of the setup on your boat but I can flush my system in or,out of the water. I use the 5 gallon bucket method and get the solution into the raw water system by using a tee connection in the in-line raw water hose. You do not have to remove the impeller. Once I see the solution coming out of the exhaust port I shut the engine down and let it sit for 3-4 hours then flush the whole system with fresh water.
Cheers,
Karl

 

[Fisho]

I use Rydlyme and the the same procedure as Karl. Works a treat. Feed in from bucket the same way you flush the raw water side of the heat exchanger. There is quite a bit on Tugnuts about this over the years.

 

[Fisho]

I should have mentioned that every time I flush my engine using Karl’s bucket method (after each outing) I put half a bucket of diluted Saltaway through system before a final flush with fresh water so no residue of Saltaway is left.

 

[BB marine]

I have two different ways set up for flushing or winterizing the engine raw water system. (1 out of the water) I have a small kiddy pool and a 120volt Simer Geyser pump. I pour the anti freeze or flush in the pool (5 gallons) I attach half of a Mercruiser stern drive flush devise. Part 881150Q1 to the thru hull screen bottom of the boat. Thru hull valve open turn the pump on the pool is under the boat so it collects the spill over. Start engine, once antifreeze or flush comes out of the exhaust, shut down engine.

(2 In the water ) I added a flush port to my sea strainer. I fill a 5 gallon bucket flush solution Vinegar and water mix for fresh water use or a recommended product for salt water. I attach a 1" hose made up to be attached to the flush valve. With flush valve closed and thru hull valve open I start the engine once I have water flow I shut thru hull valve and open flush valve at the same time. When the bucket is almost empty I hit emergency shut off button.

Altered flush devise . the hook attaches the the thru hull, cup is pulled up tight against thru hull. Hose and pump is attached


Flush valve, It takes less then a minute to pull 5 gallons through.