Hi Scott,
The shaft of the carb can be reversed since a throttle stop isn't needed with a servo. Care must be taken to replace the throttle plate unreversed and locktite the screw. You can't flip the carb because of the pulse port through the manifold. I left the carb stock until after I test run the engine. Since this is a blower it has a large carb already(10mm). This should be enough for a 25cc. I cutoff the hex section of the impeller hub and drilled out the back to allow it to slide further down on the shaft. I cut down the spacer tube also to match. Notice that the exhust port is larger. I trimmed away the small lip in the port accross the top and at the ends. This gives the engine a 75 degree before top dead center port opening. The sharp edges inside the cylinder must be removed after opening a port. The stock muffler will used for basic testing. I will spend the money on a wacker muffler when it is install in a plane. This is one of half a dozen engines that I am working on and I just put a flywheel on that was on the bench for pictures for you. The stock port timing is: intake=66 degrees, exhust=60 degrees, transfer=50 degrees. Wear a mask when cutting the case, because the magnesium alloy produces airborn particulates when filing or grinding it.

Dave