914 rough running

Re: 914 rough running

by Rob Seaton » 11 years ago

Rob Seaton

3 1.32k 251

Are you using any power at that low RPM? or just transitioning through this range? What is your take-off RPM? Hopefully you are not overloading it and causing detonation...

Re: 914 rough running

by Greg Regan » 11 years ago

Greg Regan

25 75 31

Thanks for your interest Rob. Could the carby imbalance at those revs cause the knock meter to light up a bit more It seems to do it at any load on the engine ,even coming down on the throttle with the prop fine

Re: 914 rough running

by Przemysław Wiśniewski » 11 years ago

Przemysław Wiśniewski

65 247 3

Hi. What are minimum safe takeoff RPM? I have 912UL and 5000RPM maximum (takeoff power).
This set of ground adjustable propeller let me get economic fluel flow (about 12lph @ 4200RPM on cruise) and dynamic takeoff. But it is good?

Re: 914 rough running

by Rob Seaton » 11 years ago

Rob Seaton

3 1.32k 251

Hi Greg,
Sure, it could be carb imbalance at 3000 but above approx 4000 it should be smooth regardless of carb sync.
Have you tried a dynamic prop balance? It is well worth the money.
What is your take off RPM? The min is 5200 but the MAP is going to be 40inHg at full throttle so even a min of 5500 is a lot of boost for that piston speed. (A constant speed prop is ideal for the 914).
(Przemyslaw: 5200 also for the 912 series, see SI-912-016)

Re: 914 rough running

by Przemysław Wiśniewski » 11 years ago

Przemysław Wiśniewski

65 247 3

SI-912-016 is "selection of suitable operating fluids" there is sth about RPM's?