I don't remember the number of hours on that motor when I bought it but when we tore it down for rebuild it was very clean. Piston tops were not showing carbon buildup and rings were clean. The motor failed due to a retaining pin, not degraded oil. When we goy it back from the builder, I used Amsoil to break it in at 100 to 1. It smoked a little during break in but after that period I ran the normal formula and other than a small wisp of smoke at start up it was very clean. I sold the boat a few years back and the new owner has called me on a few occasions to ask about some mods. I made to it. He tells me he hasn't touched the engine except for maintenance and to replace a starter.