Re: 2003 Ficht VRO
A FICHT engine does not have a "VRO". It uses a multi-line oil injector that is electrically operated by the engine's EMM (computer).
The smaller 1/4 ID line is the oil in hose, and the 5/16" ID line is the return. You need the return oil fitting on the oil tank, drilled and screwed into place.
There is a special oil bleeding sequence that is required before and during engine startup. You should also have a laptop and the diagnostic software to set up and check out the engine.
Since you are not familiar with this type of motor, find a qualified tech or get the factory service and the rigging manual so you can understand the systems and hook things up correctly.
They are great motors but can get very expensive if you mess something up.