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I'm not an engineer or test pilot but I though some might find the following useful.
A friend of mine has a Lightning with a Jabiru/Bing installed. His engine became erratic in cruise and even died when he pulled the throttle back. He landed power on, on a long runway. After much investigation he discovered that the balance tube between the intake plenum and the Bing carb had disconnected. Reconnection solved his problem.
Moral of the story is: secure that tube!
His must have popped of during cruise. My story starts on the ground. The connection at the Bing is to a very small stub fitting. I have knocked it off several times while doing work around that area. Once I knocked it off during my phase 1 flight test period, didn't know realize it, and went flying. Nothing out of the ordinary showed up during the run-up, and initial take-off, but on climb-out, I certainly noticed the engine was not happy. It was running rough, but running none the less. I turned back into the pattern and was able to make an uneventful landing. I checked undercowl and found this line popped off. I reconnected it and flew again immediately with no further problems.
Indeed, the moral of the story is: secure that tube!
I used safety wire to secure each end of the tubing ... just don't over-tighten it and cut the tubing.