Stumbling 914 only at runup
in 912 / 914 Technical Questions
6 years ago
Here is what has happened the last 4 times I've used the plane. It's a 914 ULS, 2016 aircraft. The engine has been running fine for a year (carb issues a year ago, carbs replaced and has worked without issue since then).
The plane starts normally, and then warms up past 50C. I then start the runup. The rpms increase into the 3000's, and it's here where the engine stumbles roughly. As I push the throttle further up to 4000, the engine runs fine, and even at full 115% power application there are no issues.
This stumbling appears to stop after running the engine further. I have flown 3-4 times since this occurred, and no issues have occurred on take off, in flight or landing.
I have uploaded video of the stumbling on runup.
https://www.dropbox.com/s/ugbiv7zzzf3x7ux/914.MOV?dl=0
Any ideas? It's seems strange that it only occurs in the 3's, and not up at full throttle. It is a very pronounced stumble, so I'm concerned it is something that could get worse. Thanks!
The plane starts normally, and then warms up past 50C. I then start the runup. The rpms increase into the 3000's, and it's here where the engine stumbles roughly. As I push the throttle further up to 4000, the engine runs fine, and even at full 115% power application there are no issues.
This stumbling appears to stop after running the engine further. I have flown 3-4 times since this occurred, and no issues have occurred on take off, in flight or landing.
I have uploaded video of the stumbling on runup.
https://www.dropbox.com/s/ugbiv7zzzf3x7ux/914.MOV?dl=0
Any ideas? It's seems strange that it only occurs in the 3's, and not up at full throttle. It is a very pronounced stumble, so I'm concerned it is something that could get worse. Thanks!
