Cylinder scoring can also be caused by running 15W-40 for long periods of time-especially in hot summer months. I don't have the link, but there are pictures of comparing cylinder liners run on 15W-40 and with straight 40 weight. The difference is dramatic, and after seeing that, you'll always run 40 weight. Yes, military runs their 2 stroke engines on 15W-40, but they also only have a 2000 hour requirement before overhaul-which on a military vehicle is about 60-80,000 miles. Then they just pull the engine and install a fresh one-on our tax dollar.
When I ran the 8V-92TA in my truck, I had it overhauled for the first time at 500,000mi. They said I could have lightly honed the cylinders, installed new rings and be down the road. But I had the newer designed liners, pistons and rings installed and my oil consumption went from 1,200 miles per gallon to 2,200 miles per gallon burned (my engine never leaked). Good Luck, TomC