Ive seen an 82cc be a bit snug on the pto with that same dowel not perfect. However the cp55 does not have that aluminum piece around the bearing. Its 54cc. Im still convinced it was the housing just a few thous tighter than the others for some reason. Perhaps thats why it was in my pile to begin with. I got it in an alotment of stuff off ebay at some point. So who knows. I know ill not likely use it again...lol