The verdict isn’t in, yet. Ron
After looking and looking at mine my money is on 57cc the corner around the decomp is square on a 70cc. It doesn't have the two bosses in the side for the muffler so 80 81 850 is out umm it has a decomp out the back so 805 800 is out 54cc is out due to the decomp. This has been a fun little quiz night learning experience haha