Hi

Lets see..........bet that a 2 buck light bulb made in china by a 9
year old will protect your $10,000 engine.

If RW cooled, stick you engine water intake into a bucket of
antifreeze. Keep it running until you see the stuff blowing out the
side of your boat. If FW cooled do the same and then check your FW
collant with a 3 buck tester. Top FW system if necessary.