912 iS Sport - cyclically vary RPM

Re: 912 iS Sport - cyclically vary RPM

by Uladzimir » 9 years ago

Uladzimir

1 8 0

Thank you very much for your advice. Now it is clear where to begin.

Re: 912 iS Sport - cyclically vary RPM

by Uladzimir » 7 years ago

Uladzimir

1 8 0

Yesterday, when the Touch & Go manoeuvre was running, the engine rpm was in the range of 5800-5500, and changed cyclically for a few seconds.
Airplane TL-3000 Sirius, engine 912 c / n 7703277, variable pitch propeller hydraulic manual, running time 162 hours on Garmin. Operating time according to ECU - 267 hours. // I do not know why such a difference, I bought a new plane with a new engine //
I want to ask for advice, than it can be caused by such work of the engine.
Now I have the downloaded engine logs. Line A, Log 833, time 267:14:55

https://drive.google.com/file/d/1hH4Cgj2kWCm7sjwDPw5ozlmgYv2q_4Mt/view?usp=sharing

thanks to everyone

Re: 912 iS Sport - cyclically vary RPM

by Roger Lee » 7 years ago

Roger Lee

131 5.38k 5.44k

Hi Uladzimir,

Was this a one time occurrence with the engine stumble or did it happen more than once? How drastic was the rpm up and down cycle?

---

Roger Lee
LSRM-A & Rotax Instructor & Rotax IRC
Tucson, AZ Ryan Airfield (KRYN)
520-349-7056 Cell

Re: 912 iS Sport - cyclically vary RPM

by Uladzimir » 7 years ago

Uladzimir

1 8 0

Hi Roger,
Recently it was once. But this situation was more than a year ago.
After your advice, I adjusted the torque on the overload clutch and increased the minimum pitch of the propeller.
Frequency of rpm up 5800 and down 5200 cycle - two times per second. Subjectively it seemed that in this mode the engine power is very small.
Maybe this is somehow related to the low air temperature (minus 12°C)
On the diagram it will be more clear what happened



BR

Diagram.png (You do not have access to download this file.)

Re: 912 iS Sport - cyclically vary RPM

by Uladzimir » 7 years ago

Uladzimir

1 8 0

the quality of the image is lost when uploading.
here is the link
https://drive.google.com/file/d/1A8_63FDK81VQF3CFgae7uczWwBoNqki2/view?usp=sharing

engine speed fragment

Diagram_fragment.png (You do not have access to download this file.)