Originally Posted by Scott Fisher

Its not the same engine although Sirio does manufacture the engine. While I didn't compare the internals I did ask about our team manager about using the same conrod. He said he spoke to Adrien via email as was told that they don't use the same rod. Maybe thats a load of BS but that is what I was told. I do have an Orion rod coming and can compare them myself to see.

I can also tell you that the needle settings between the two carbs are very different. The high speed needle in the Orion carb is buried much deeper into the housing than with any of my sirio engines.