Most aircraft piston engines have at least one soft spot, preventing them from being 100-percent reliable over time. With big-bore Continentals, it’s often cylinder wear. Small-bore Lycomings, on the other hand, can be susceptible to premature camshaft wear. Of course, run any engine long enough and hard enough in any machine and it will ultimately fail. In aviation, though, an engine’s long-term reliability is by no means assured. That’s a lesson I learned the hard way.
The Cessna 210 I owned for a while was in overall good shape, with a mid-time engine. For the first couple of years I had it, I spent a lot of time going through it, often with an experienced A&P/IA, replacing worn screws, bolts and bushings, and cracked plastic, repainting small components, plus cleaning and inspecting various items, including the spark plugs.
