I lit a candle in celebration of the demise of the LA 40 and I have never used the 65 but I have been given a lot of the 40s that were stuck on the end of trainers that were given to me. Total dogs but I have still never had a flame out with the 40 or 46. I found the air bleed carb idiot proof and didn't see the added tons of power when comparing the LA against the FX. The new AX is a different mater. At one point I had 8 of the LAs installed in my Uproars during the fun fly era. I just gave away the last one I had two years ago so a friend could replace the old Fox he had in a plane. Much improvement. And for the price they are hard to beat unless you plan on flying with a 46 for a long time. Then the cost of the AX may be worth it? I do feel OS has priced themselves out of the reach of a lot of new to the hobby people. As I mentioned, I haven't bought a new engine other then the SK in a long time. I buy used and rebuild. I only know one guy at the lake bed that has bought a new small two stroke OS engine. I do see a couple new four strokes but for the price people I fly with have all gone bigger and are using the DLE gas engines.