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Hi All...Had an interesting one this weekend. Was 4 hours into a 4.5 hour CC from S. Fla to near Charlotte NC. Flight and Wx were perfect the whole flight. I was in cruise at 9500, when all of a sudden I had a power loss, slight vibration and some very angry noises coming out of the motor. I was in the startle effect, as this came out of nowhere, for probably 10 seconds. I hit the boost bump, switched the tanks, checked throttle ,mixture and mags and all were as they should be. The issue continued and after about 30 seconds I decided I didn't know what was happening and I wasn't about to find out if the engine was in the mood to eat itself!!! I pulled the power to idle and made an emergency landing to an airport about 10 miles away. The landing was uneventful and the engine never quit, so I was able to taxi out. After about 20 minutes, I went back to inspect for anything obvious, leaking oil, metal on dipstick, odd smells or sounds and all was normal. I started it back up, ran it up and it was totally normal. As the AP on the local filed was gone for the day, I left the plane there. Spoke to him the next morning, he ran a compression check and all was in the high 70s, plugs looked brand new and ran up fine for him as well. Spoke to my local AP and this gentlemen in SC and the consensus was a stuck valve. I was able to get back to the plane to download the engine data from the flight. The first image shows that everything was normal, and then it gets messy. The other image is the exact moment of the "event". You can see that the EGT on Cly 1 drops off a cliff. I know the scale is not on this image, but the EGT1 dropped about 450 degrees in 5 seconds. Does a "stuck valve" in flight represent like this, has anyone else experienced this and what is the fix. I am getting a few different opinions from the 2 APs, but curious what the Mooney brain trust here thinks... Thanks All