My 1986 150 has beening over heating off and on for the last 2 years. Put a water pump kit in it the beginning each spring. I took the spark plugs out and looked at the top of the pistons. One side looks to be too clean. It also will start blowing steam from the pee hole. Compression(119psi) on the side that the pistons look cleaner is about 1 to 2 psi lower than the other side which is 121psi. Could this be a bad head gasket?
