Hi all engine experts. I will begin work soon on an aerobat and would like to move from 2 strokes to 4 strokes. I am considering engines from the following brands: Saito, Magnum and OS. in the .91 to 1.20 range. Is there any problems that you have experienced when mounting/flying these engines inverted? problems specific to a brand or to a particular model? Due to price I am not considering the OS that has the pump

thanks in advance

It is important to make sure that you have the level of the fuel tank at the height recommended by the engine manufacturer. Often times this means that the center of the tank, as viewed from the side, needs to be at the same height as the needle valve of the carburetor. If the tank is too high the gas may siphon out of the tank and the engine may not run well. Once you have the tank mounted correctly then carefully adjust the needle valves for proper operation of the engine. After this is done the engine should run as well as if it were mounted upright.

Another thing to consider with inverted mounting is access to the glow plug. On most 4-strokes it is angled back some, and you either have to make sure you have a straight enough shot to the plug for your glow starter (sometimes the firewall bottom can get in the way), or use a remote starter socket, or if you use an on-board glow system, (not really necessary, but nice) that will take care of it , too. I'd opt for the remote. You can locate it back from the engine area, don't have to reach near the prop to remove it.