" Hi All,
Joe (Foster&#
" Hi All,
Joe (Foster) I had a bad experience with my 1990 Evinrude 225 HP. The top starboard piston had to be replaced. I was teaching at a vocational high school and the marine engine instructor was both a friend and an OMC Master marine mechanic. We rebuilt the engine (a complete rebuild) in 1996. We ran it for an hour in the test tank at the school then took it to the lake to make final ajustments. While idleing away from the ramp the engine started a heavy knocking. We pulled off the cylinder head on the starboard side and nothing on top there. We pulled off the port head and there was a piece of ring on top of the piston. This caused a second rebild and trip to the machine shop. Almost the same thing happened a week later except this time number 5 piston broke after 1.5 hours of operation. The OMC factory rep came to the school and went over everthing we had done and took away the entire power head. 3 weeks later we received a completly new power head, but no explaination. Later we managed to find out that a "lot" or "batch" of pistons had been manufactured and the process of baking or annealing the pistons was skipped. This heat process locked a pin in place that kept the rings from turning in their grooves. This was determined to be the cause of our problems. I was out about $3,600 dollars in parts and machine shop charges, but I have gotten many hours of use out of the engine and it has been perfect ever since. The moral of this story is if you do rebuild, make sure to avoid these pistons with the loose pins in the ring grooves.
This is a great site. Thanks to Joe Reeves and the other guys that know about and are willing to share information on OB motors.
Frank (Sebastian) "
