Q: I have a Lycoming IO-360-A1A on a Mooney E model. My mechanic tells me that there are two timing settings for this engine: 20° and 25° BTC. The engine had been set at 20° BTC and he reset it at 25° BTC. What are the advantages or disadvantages of this timing change? The engine is running slightly warmer and appears to be a bit louder in the cockpit.
DAVID WALKER, via email