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I just tested the compression on a 1979 Johnson 140HP, I cleaned it with seafoam, removed all spark plugs and tested the compression, it come out like this #1 110, #2 115 #3 130 #4 75 can someone tell me what is that telling me.
I agree with dsinger, Take both cylinder heads off and inspect the cylinders. Then take the by-pass covers off and see what the rings and pistons look like. Tell us what you find.
