So it apparently sends an error into console which isn't there. The error is:
Property propulsion/engine[0]/MilThrust has already been successfully bound (late).
Failed to bind the property to an existing already tied node.
OK, thanks, that info lead me straight to the culprit, the xml file for my engine had 2 entries for Milthrust, strangely one was exactly the same as the idlethrust figures, it's weird because I didn't edit that file since the first upload of my model.