Fuel Consumption

Thanks to all responding to my topic.

Yes, I know that a Rotax 912ULS is burning much less fuel than my Rotax is doing. In fact that is why I'm asking what can be wrong since I use that much even when the engine is running on 55% power setting.
Does anyone know what can be done about it?

What is the correct needle setting?
can the setting of the idle mixture have any influence of the fuel consumption ?

Can I slightly wrong float hight have any influence?

Regards

I'm trying  to find out why my engine is using around 33% more fuel than other 912 ULS'

Hi,
I'm not sure how you can say that my fuel calculation is wrong.

This is all a tad vague - To compare fuel consumption per hour the variables ie measured refueling, power setting, altitude, temperature, need to be standardised or at least accommodated.

My Cruise fuel flow indication rarely drops below 17L/hr, which is just rubbish, given my actual average fuel consumption.

The fuel flow gauges/sensors in light aircraft are notoriously inaccurate - measure the amount of fuel required, to refuel to a known point and divide by the time flown (I use Hobbs others may use clock time).😈

The correct needle setting is the 3rd notch from the top (page 288 Maintenance manual Heavy) as you have. 

Are your vent tubes in a good ram air/vacuum free zone? Follow the installation manual advice for this and it should be good but any ram air to the vent line will increase fuel consumption.

I suspect you are using a fuel flow meter to judge this, and I also suspect it is inaccurate because you should see a significant change in fuel flow at 55% vs full power. I suggest you start recording and carefully monitoring actual fuel use to get a better idea of fuel consumption.