Fuel Flow

[SkippyDiesel]

My fuel consumed/remaining has been calibrated within 1/2 Litre - all good!
My system uses two "red cubes" - Rotax 912 ULS - one cube on supply line, the other on return to tank.
I assumed that an accurate fuel consumption callibration, would translate into an accurate fuel flow read out - it doesn't seem to.
My inflight fuel flow readings are way too high. When the fuel being consumed should be in the vicinity of 13-14L/hr its reading 18-19 L/hr.
Anyone have any suggestions on what might be the problem/how to fix?
Thanks

 

[SkippyDiesel]

Drawn a blank?

 

[jakej]

First easy thing I‘d do is connect tubing to the outflow side of the cube & have it go to a container.
turn the electric pump ON & after 1,2,3, or however minutes you want. Then turn it off.
Measure the amount of fuel that flowed out & do the maths also using the data from the computer.
That could help a lot & will confirm whether the FFlow unit &/or K factor is accurate or not. HTH.

 

[SkippyDiesel]

Thanks Jakej - Done on the return line - prior to test flying - 7L/hr.
I know it sounds crazy but the maths isn't giving me the result you/I assume it would. Could be my maths, always suspect but did fellow the formula. Could be something else - strange that I was able to get the Used /Rem spot on.