Test hop 6
A lunchtime test flight to gather more data for troubleshooting the engine problem, and see if the idle mixture adjustment had any effect. Result: 5 in-flight power reductions to idle showed consistent results…the #2 cyl EGT drops to around 550 degrees, while the others run 800-900. With the throttle above idle, the EGT spread is quite small.
There was no solo #2 EGT drop on the downwind power reduction this time, but that’s just a single data point.
The stumble showed up again on final approach and the taxi back to the hangar with a hot engine and low RPM’s. My perception of the stumble is that each “dropout” is now dropping more RPM’s, and is longer in duration, than it was previously.
Update 8/20: talked to several folks today including a local engine guy and the engine shop. I sent off the latest data logs to the engine shop, they’ll get back to me tomorrow with their next recommendation, which it sounds like may involve pulling a cylinder, according to their tech. Swell.
Lovely weather has been hanging around, hard not to be a bit frustrated with these problems limiting ability to get up and dig into the flight testing. It’ll be obvious when the engine is fixed–the cruddy weather will return!
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