This johnson was given to me with both spark plugs stripped. I removed the head and inserted helli coils to resolve this problem. A tune up was performed and the water pump was replaced. when replacing the lower unit oil, I found it to be milky brown. I realize that this means water is getting in, but I decided to replace the drain and vent plug washer and test run to see if water still gets in. During my test runs the motor knocks. I spun the original prop, purchased and installed a new one, and then it broke the shear pin. the shear pin has been replaced, and has not broken again. this may be because I've only gone half trottle to aviod it from happening. Is the problem in the lower unit or could it be the drive shaft that goes into the power head? Is this motor worth any more of my time?
