Gunked up cooling system

[motion30]

My westerbeke diesel generator was running cool, not getting up to running temperature
after changing the sending unit for the gauge I diagnose the problem as an stuck open thermostat today I change the thermostat but the coolent in the generator look like it came from a mud bath. What is a good product to run in the cooling system to help de gunk.the system? Keep in mind the Mitsubishi engine in this unit an aluminum block

[a64pilot]

Water, lots and lots of it.
What I do is go to Walmart or depending on where you are of course and buy a Prestone flush kit.
Install it in a coolant line that it will fit into, it’s meant for the heater hoses in an automobile, then with the T stat out run fresh water through until it’s pure and clean, then start the engine and let it run some to ensure all the water is circulated and is still clean.
You may want to use a piece of plastic or something to not soak the generator.

I don’t like flush products, although there are many that say they are safe for aluminum.