Long time lurker, first time poster. I'd like to relate a story that has happened to me now with two separate aircraft I've flown. The scenarios are so similar that it doesn't seem like it could be a coincidence, but I'd like to see if anyone has ever heard of this happening.   I had a 1968 M20C with several partners about 6 years ago. After we did an overhaul and had flown about 40 hours, one of my partners was flying at about 6000 feet when he noticed the throttle un-responsive. The linkage