Good morning gentlemen, it seems that there are some very knowledgable Sthil folks here so I will ask a question, I have just finished converting a Super 045 that my brother purchased new over twenty years ago. The rings were remade for me by the gentleman in NM so I know it is a 54mm bore and I measured 38mm stroke using a machinist rule and eyeing it against the edge of the spark plug hole. My calculation shows 87cc but that seems a weird number. does anyone know the official size of this thing? I ran it last week using the original muffler and have yet to decide what to use on the plane I am building for it.