Fuel flow

[AndyDunx]

Following recent 5 year Rotax service . Normally my fuel flow at cruise ( 5300 rpm ) is 19/20 l - ( Electric boost on or off )
Now seeing 19/20l with electric pump off - 25l with electric pump on . With engine off and electric pump on fuel flow of 8l
Fuel pressures appear normal ( have the upgraded higher pressure pump)
Wondering if transducer is faulty ?

 

[Avanza]

A fuel transducer has a small wheel that is read by an optical sensor.
It's possible that the pulses from the electric fuel pump can turn the wheel back and fourth with no flow and that this is sensed by the optical sensor as fuel flow.
I don't think there is a problem with the transducer.
I would just keep an eye on it for a few flights.

Good luck

 

[seagull]

Following recent 5 year Rotax service . Normally my fuel flow at cruise ( 5300 rpm ) is 19/20 l - ( Electric boost on or off )
Now seeing 19/20l with electric pump off - 25l with electric pump on . With engine off and electric pump on fuel flow of 8l
Fuel pressures appear normal ( have the upgraded higher pressure pump)
Wondering if transducer is faulty ?

Is there any chance your “K” factor was changed?

 

[seagull]

I had the same concern a few years back. My “red cube” had about 1200 hrs on it. I contacted the company and they said it would be very unlikely the cube was bad. I was still convinced it was bad and bought a new one and installed it. No difference, but at least now I have a spare that works as good as a now one.