Re: 1979 Johnson 150 V6 Low Compression
Not sure what you mean by "work" on one cylinder. If you mean to bore oversize, the answer is yes. Depending on what you find when you tear it down, you may not need to bore it. The 79 engines all used high ring pistons. These high ring pistons provided great compression at the time, but were prone to fail rings due to carbon around the rings. The annual "decarb" on these early crossflows was important for this reason. Once you loose compression on one hole, you are probably looking at a teardown. I'd pull the head and side bypass cover on the low compression side and have a look. I'd get hold of an original factory manual from OMC-specifically for that year. You can contact Ken Cook co, in Milwaukee to get a copy.