radiator cleaning

Hey ledger on my 1983 Honda CR250 the radiators were completely plugged with the magnesium from the water pump cover, when you looked down inside the radiator you could see that each tube was completely plugged .

A friend that I met in my local vintage club, who's really into restoring the 1980s Honda's told me to use 1part muriatic acid to about 3 or 4 part water. Plug up the radiator so it will hold the mixture, pour it in and let it sit 20-30 minutes, then flush it out with your hose and watch all the crap come out , I had to do this about 4 or 5 times to get mine to flow free, before I started when I poured water in the top hardly any came out the bottom, after flushing it I had a nice strong flow, when I was done you could see each tube was completely clear and it look like a brand new radiator.

If your radiators are not that plugged up you could probably use a less concentrated mixture and fewer flushes.

When my buddy told me about this I was a little skeptical about pouring muriatic acid into my aluminum radiators, I have been using the radiator now for about a year and have seen or had no ill effects so far.

I have also found that muriatic acid works great at completely removing rust from steel, just make sure when you use it to wear some kind of breathing filter because the fumes are seriously bad , and also make sure you wear some really good chemical resistant gloves as well , you don't want to get this stuff on you skin. This is mainly if you are using full strength to clean rust, when using the 4/1 ratio its not bad , I would just wear some of those blue nitrile gloves and no mask.

Hope this helps

L8ter

Yes but I'm sure the acid will eat it up as well, it basically eats up all your unwanted crap .

The ONLY way to clean early CR Radiators is to cut the top of the tanks open and rod out the cores.The left radiator will be plugged shut and no chemical will do it I know I built at least 100 of those early CR's and every one I ever did was plugged.