Originally Posted by casey1999
I have a Yanmar 3GM. What the is best material to use to try to flush the sea water cooling system? Engine is direct sea water cooled. I will hook up a hose to the cooling water inlet (by pass inlet sea ****). The hose will be connected to a bucket I will keep filled with the flushing solution. Will a mix of 50% vinegar work or is Salt Away good? I have heard acid is good but would prefer not to use.
1- Get an acid proof or resistant pump even a $6.00 drill pump works
2- Get some Rydlyme!
3- Remove the t-stat and re-assemble the housing
4- Disconnect the exhaust water injection hose at the injection elbow
5- Add a hose extension to this hose to feed it back into a 5 gal bucket
6- Remove impeller and put cover plate back on.
7- Stick the RW pumps intake hose into the mix of Rydlyme and water in the 5 gal bucket and flip on the circulating pump.
7- CIRCULATE the Rydlyme from the bucket through the engine then back into the bucket per time frame and instructions.
8- By removing the t water injection hose from the exhaust elbow you will not fill your waterlift muffler and engine block as the liquid will be flowing back into the 5 gallon bucket not into your cylinders.
9- Run fresh water through the block mixed with a little baking soda to neutralize it
10- Re-install new impeller & new t-stat and re-connect the water injection hose.
11- Run engine hard for about an hour under load to build back the "good rust" and oxide layer inside the engines passages.
12- You're done.
This is the same procedure except on a FWC engine where I removed the HX and used the inlet/outlet for circulation of the Rydlyme.