Has anyone played with different 7mm venturi inserts? Red's has a new one with more of an oval shape to one side and so does PROTEK for their samurai motor. I know there have been several other venturi inserts that were off set to one side. Never used one before to know if they work? I think novarossi with Mito case was trying to accomplish something similar? However, they went back to a MITO C for high end on road motor.