Well, maybe they are not planning to make new parts for the 6550, they gotta stop sometime. However I suspect it is more RJl/Mecoa inefficiency. But they do have a more current ABC engine. Hopefully they will get on with its replacement and maybe a larger version as well. But I don't have much faith in RJL/Mecoa doing anything other than to keep making the same engines, and keep poor inventory of parts.