Fuel not delivered from radial tanks

[TanoPrime]

Making a (probably over-complicated) ship, and would like to attach more fuel on the side (rocket is already tall enough to nearly be unwieldy).

However, it appears that my engine doesn't feed from the tanks attached with the TT38K radial decoupler (tested also in flight). Google and forum searches tell that radial decouplers have crossfeed enabled by default (and indeed it's not possible to toggle this option from the part menu).

Any idea what the problem might be?

Screenshot:

[Geonovast]

From the looks of it, you're early in career, and you haven't unlocked the node in the tech tree that allows crossfeed.  I believe it's the one that has the fuel line it in.

 

Edit: Oh!  First post!  Welcome to the forum @TanoPrime!

Edited October 24, 2018 by Geonovast

[TanoPrime]

Thank you @Geonovast !

Enabling crossfeed works on other decouplers without the fuel systems tech, but I can kinda understand the logic of it.

Alright, not worrying about it anymore then, will figure out some other way of making it work - maybe try to accomplish less per single mission, this got complicated due to wanting in the same mission to send up 3 tourists, have deltaV to spare for two stranded kerbal recovery missions, and to deploy both a long range probe and a keosync relay sat.