Bought a boat last August 2018 with a Johnson 115. The guy said that there is a definite miss. We didn't start working on this boat till a week ago today is 04/04/2019. Prssr ck 4 cylinders 3 read 120 psi. #1 cylinder read 90 pulled cylinder cover off, at first everything looked good no gouges, no scratches holes, cracks, etc. Then we seen a very small chunk on the piston edge( about a 1/32 second if that ) that went down to the ring. Tried to use a flashlight to see if piston or ring was broke or cracked, but found it wasn't. It was in tack. I still don't understand the 90 psi. There is not any blow by and the ring is still seated correctly. so if the compression ring and the scrapper ring is seated what's making the 90 psi ?
