I have put a lot of hours on this engine in the last 2 or 3 years, much of it at full throttle, so I don't think its a missing lube tube or that would have shown up long before now! I also happen to know that the other end of the tube just comes to an end behind the diffuser, it's not connected to anything inside the engine except open space, and that the lube is Tee'd off the main supply inside the engine rather than under the purple cover.