Here's an example of ABC durability. I have an OS61RF in an old pattern plane. It does not have a pump so it must be tuned four-cycling rich with a full tank, at the end of the flight it will occasionally sag lean. This engine gets an extreme range of temperature every single flight, and from the very first tank of fuel. So far the liner is intact and still making great power. I'm sure it helps flying from concrete where little dust is ingested. Unless its an extremely tight engine, like an old Fox or Supertigre, just fly it.