Nope,im not sure either.But you have the proof in your hand.All i know is i called Ralph and asked him what i had.I told him i measured the bore and stroke and came up with 55ccs.He said it was definatly a Q52 if it had mounting lugs on both sides of the engine for the coil.He said it could be run from either end.So as sodbuster said in his post it could be either.Well, i just learned something else new right now.