Reply To: 1961 Johnson 40 (RDSL-23) stops pumping water

[frankr]

Not meaning to be a pessimist, but you do realize that motor has long outlived its salt-water life expectancy, don’t you? Mine lasted four years in salt water use. Nevertheless, there is hope.

Here are a couple of things you might consider. Take a look at the gasket edges where the exhaust cover meets the block. You will see the edge of a metal baffle plate between the two gaskets. If that plate is thin (about as thick as a credit card), and stainless steel, that is a good sign. But if it is thicker (close to 1/8″) and made of aluminum, it may have a hole corroded through it, allowing exhaust to blow into the cooling system.

Secondly, those motors have a haven for electrolysis at the juncture of the head gasket and cylinder block. The aluminum surrounding the iron cylinder liner and sealed by a copper/brass fire ring in the gasket corrodes away, resulting in head gasket leakage. This is what killed mine.

Admittedly either of these conditions would normally result in water intrusion into a cylinder, but who knows? And removing either of them could destroy whatever is left.

With that, I wish you good luck with your worthy project.