Back in 2012 or so, I had a constant overheating problem on my old Evinrude 115 Ocean Pro. In my local shallow bay systems, we tend to pick up a lot of shell and sand in our motors. Changing water pumps and thermostats made no difference and my local shop wanted to do the muriatic acid flush on it. I thought that was too extreme so after some research I settled on the Hammerhead marine descaler which at the time was the only descaler specifically advertised as being safe for use in aluminum outboards. Despite doing a 15 minute water Salt Away flush after every run, the first treatment with Hammerhead pulled a pile of sand, tiny shell fragments and scale out of the motor and the overheat problem was solved. That’s when I started doing the annual descaler treatment. Shortly before selling that boat and motor, I pulled the cylinder heads off just to have a look at the water jackets – they were very clean with no sign of etching or pitting caused by the descaler treatments. I’m still not convinced that running hydrochloric acid through a motor is a great idea, but as long as you thoroughly flush the motor afterwards, it’s probably OK. My old 1998 115 Ocean Pro is still running strong with one of my neighbors with no apparent ill effects from my descaler treatments.
Bob
1937 Champion D2C Deluxe Lite Twin
1954 Johnson CD-11
1955 Johnson QD-16
1957 Evinrude Fastwin 18
1957 Evinrude 3022
1958 Johnson QD-19
1958 Johnson FD-12
1959 Johnson QD-20
1982 Evinrude 25hp
“Every 20 minute job is only a broken bolt away from a 3-day project.”
"Every time you remove a broken or seized bolt an angel gets his wings."
