Hi GG. Thanks. Aware of that, as I thought the grammatical phrasing intimated apparent?
By O.S. convention, anything FP or LA with an -S suffix was C/L. Without suffix indicates R/C carb version. e.g. FP vs FP-S, LA vs LA-S. Those specs I quoted in a prev post were from the actual spec sheets supplied with engines in their respective boxes at the time BTW.
Back in era of MAX-15 pre suffix other than annotation C/L or R/C , the engines came supplied with two venturies in the box. One for C/L, fitted, (the smaller diam) and a second for FF in a bag. In the era of FP-S they came supplied only with a single venturi intended for C/L. If you wanted a wider throat for FF, it was a purchaseable accessory.
I've tried a few engines in Akromasters, Peacemakers & Smousens amongst others in class over the years. Akro would fly on both of those engines above, or even an .09 Rossi, Cipolla and probably even an ENYA too. Just not or up to standard of my expectations in what I want the Akro to do. As per earlier, OMMV. With the right powerplant and built light, it's a fabulous airframe.