This may be old news but.....I've just discovered that the Webra MC carb's throat OD is the same size as the ST 2300, meaning that it should just drop-in. For those fighting a rich midrange, this could be the answer. Not to mention, with the cheap prices on the ST, buy an MC carb, Perry or Webra external pump, and a Karl Mueller header and pipe of choice, could be quite a bargain pattern motor, particularly thru Intermediate. The only question is which MC, the 9mm or 12mm ID? The factory ST carb is 11mm ID. Too bad the MC won't fit the OS 160. OS does make an MC carb for the 140RX, but Great Planes won't import it, I suspect they wouldn't be able to sell as many EFI motors. I think it would fit the 160FX but you would have to drill the holes for the carb retaining screws and you'd only get one shot. Can anybody tell me how much more potent the OS 160 is than the ST 2300?