Fuel pump noise

Is the Fuel Shut-Off Valve OPEN???
They are not meant to run dry.
Are you seeing fuel returning to the tank from the Fuel Regulator return hose?
What Fuel Pressure are you seeing?

May be loose in its mount and shaking when on or like Bill pointed out no fuel.

Tnx for your inputs Bill and Roger, your input is VERY much appreciated :)

I have made a video where the noise can be heard, both from my friends airplane and mine. Just in case its supposed to sound like that.

I see 2,6 bar - the noise is like in the linked video when flying, so I guess the flow is correct?

 https://www.dropbox.com/sh/9tu23tv9unmym68/AADUTjuagF6VGPEQa3ZI8UYKa?dl=0

Your friend's pumps sound normal
Your pumps are screaming!!!
They sound like they are drawing Air or Cavitating. (Or running on 24 volts!!!)
Are you circulating Fuel?
"I believe so", is not the correct answer.

Pull the Fuel Line off the Fuel Regulator output and re-direct the flow into a small container.
You should see one Liter delivered every 30 ± 15 seconds.

Michael Rubio

This has been a past complaint from others and you do not have to do any testing.

Please fill out a CSIR report form on your fuel pumps found below:

https://www.rotax-owner.com/en/40-uncategorised/110-csirqa

And submit it to your local distributor (Franz Aircraft Engines Vertrieb GmbH) 

info@franz-aircraft.de