Did you measure the bore and stroke on the 1-52 ? Acresinternet has this listed as a 80cc. The McCulloch 1-40,1-41,1-42,1-43,1-45,1-46,1-50,1-51,1-52,1-53,1-60,1-61,1-62,and1-63 were all 80cc according to acresinternet. The 87cc and larger engines started with the 1-70. Sometimes...