Took a while to get her mounted but finally got it done. She is a 1960 Johnson 40 HP. My partner gave me the motor as he wanted to pickup a newer 4 cycle motor for his boat. I was able to work on the motor while it was still on his boat making it easy to test during retrofit. Checked compression at 120 and 115 so I thought I had a motor worth working on. I started the motor as is and it ran but not good. Installed a carb kit, fuel pump kit, ignition kit and impeller kit, all at about $120 (didn't do the lower gear case as the oil looked to be very good shape). After installation of rebuild kits started her up once again and it ran "OK" but not good enough. I will be taking the wife out in this boat before it goes up for sale so it needs to be perfect. Pulled the plugs after running it for a while and noticed a white to gray film on one of the plugs--WATER--. I had a head gasket leak. Even though the compression was up the head gasket leaked. It may have leaked after it heated up!!! Anyway, pulled that apart and turned out the head was warped so had that milled. Put it back together and fired it up and it ran the same, "OK" but not perfect. SO what the heck is left?? By this point I had so much time the money into it I couldn't quit. The only thing left was the reed valve. Pulled the carb and reed valve assembly and found a carb butterfly valve screw lodged holding one of the reed valves open. Somebody had known the screw was missing because it had been replaced. That is to say none of the four butterfly screws were missing from the carb. Reassembled and started it up once more and now it runs like a top. Had it out on the lake when it was still on my partners boat. I really want to get it out on my 1960 Arkansas Traveler to do final adjustments. It was 35 degrees this morning. I thought I had this thing fixed about three different times. It goes to show you how many different things can be wrong with a motor and it can still run. She has original paint but took a lot of cleaning. This is the first motor I have had that doesn't have a generator, will have to stay on top of that.
Greg Anderson
Wisconsin