why this fuel ducts are not working?

[Lechu]

The engines do not want to draw the fuel from the orange engines, to which ducts are connected. Why?

Edited February 29, 2020 by Lechu

[Zeiss Ikon]

Are those small yellow blocks the Thuds are mounted on Lf/O tanks?  If they aren't, the Thuds don't have any fuel to draw from.

Fuel ducts will pull Lf/O from their supply end to keep tanks on their output end filled as long as there's supply -- but that assumed there's something for the duct to keep filled.

[Draalo]

Fuel ducts only work in one direction, notice the arrows on them: "> > >"

They are mounted the wrong way.

[Lechu]

16 minutes ago, Draalo said:

Fuel ducts only work in one direction, notice the arrows on them: "> > >"

They are mounted the wrong way.

Indeed. Thanks

Edited February 29, 2020 by Lechu