Just logged my 500th hour on the same engine model and the wear pattern is getting predictable
I've been tracking the borescope inspections on a fleet of Cessna 172s with Lycoming O-320s, and at around 500 hours the top spark plug threads in cylinders 2 and 4 consistently show the first signs of carbon tracking. It's not an immediate airworthiness issue, but it's a clear marker for upcoming maintenance. Has anyone else noticed a specific hour mark where a particular wear item always pops up on a common engine?