Re: 54 Johnson RD15A top seal (still) leaks

[olcah]

I want to post the outcome of this problem to help others. Besides the 1954 Johnson 25 HP this thread is about, I have a 54 Evinrude 25 HP (model 2512) that had the identical problem with massive top seal leakage. That Evinrude was fixed by opening the crankcase and reassembling with NO oring on the outside of the bearing as discussed below. After running about 3 tanks through the motor there is no sign of that leakage. I expect to do similar to the 54 Johnson this winter.
Thank you to Frank Robb, Fleetwin, Mumbles, Chris_P and others for explaining the top seal to me and seeing me through this. Opening the crankcase was the last thing I wanted but was required as the Evinrude motor did have an oring around the top bearing.
Here is the motor running this week.
http://i77.photobucket.com/albums/j66/c … 5euct1.jpg