I'm zeroing in on an engine and propeller order, but I'm getting what I consider an unusual recommendation from the propeller vendor. He's telling me that most of the Kitfox builders he sells props to use a 250mm diameter spinner, and that he doesn't recommend anything larger than 260mm.

Thanks to AlexM's use of a round engine, I now have his Series 7 Rotax smooth cowl, which I plan to put over a 912iS. When I measure that cowling, the circle described by the upper forward curve of the top cowling is 280mm (11") in diameter (see photo, below). It seems logical to me that the spinner should match that diameter so that there isn't any flat surface uncovered around the circumference of the spinner, and the spinner leads air directly into the two intakes.

So, my question is this: what diameter spinners are y'all using on the Series 7 Rotax smooth cowl? Any photos of installed props that show the spinner-to-cowling interface would be especially helpful, whether they're identical in diameter or not.

Thanks!

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