Water flush screw on 1953 Evinrude Big Twin?

[Caro74]

What's the big water flush screw for on the 1953 Evinrude Big Twin 25hp? It is higher than the top drain/fill oil screw on the other side, and facing the same way as the propeller. Is this to flush fresh water through if I was in salt water? Only fresh water around here. Or to drain excess water before winter? I know to run it on land the motor has to be in a bucket and the water level would cover this screw. My 1955 Johnson 25hp doesn't have it.

[1946Zephyr]

Yes, that is correct. You can actually attach a flush attachment there and run water from your garden hose though it. A lot of other models came with it, but it was discontinued about '54 - '55.