cooling system cleaning

[steve g]

I have a 2gm20f and would like to know what is the best idea for cleaning the raw/fresh water cooling system? I've seem muratic acid, clr, lime away etc... used. What do 'yall think is a good way to do it on the boat?SG

 

[Steve Dion]

Did not think that you normally need this on 20F!

Steve:I did not think that you needed to flush out the fresh water cooled versions of these motors. It is normally the raw water cooled versions that need this process. I think you can just remove the heat exchanger and take it to a radiator shop. They can clean it out for you. There was a product called Marsolve that was very common for flushing out the raw water passages.

 

[Steve O.]

which one?

The raw water intake does not need cleaning, unless your strainer gets clogged with seaweed, jellyfish, trash bag, etc. The seawater only cools the exhaust gas so it won't melt or burn up your rubber exhaust hose.The "fresh water" side of the cooling system is not really fresh water but engine coolant, aka anti-freeze. It should be repalced occasionally by draining, flushing and replacing. If you have a heat exchanger you have to get the coolant out by loosening a hose and draining or blowing it out. Search the archives here for step-by-step info on replacing coolant.

 

[Chris]

raw water cleaning

If you thought that you engine was experiencing overheating issues due to scaling of the raw (sea)water system, you could remove the hose from your thru hull fitting (with the fitting closed), place the hose in a 5 gallon bucket of 50/50 mix of cider vinegar and water. Run the engine until the bucket is empty. Turn the engine off, and let it sit overnight. Reinstall the hose on the thru hull. RE-start the engine with the thru hull open to flush the cleaning solution out. Good Luck.