My 88 osprey 170 lost power this weekend, after inspecting the spark plugs I found one plug smashed and a metal fragment jammed up inside the plug. I am thinking the metal piece was a part of a broken ring or rod bearing. there was also some pitting in the piston and head cover. I am thinking bad rod bearing since it looks like the top of the piston hit the spark plug. My thoughts are this engine is toast. so rather than invest in rebuilding the powerhead I found another engine that I believe will bolt right on, the engine I found is a 1983 Johnson 115 that was recently rebuilt. I just wanted to get some input from others on whether I am heading in the right direction or not.