I am rebuilding a 50cc 2-stroke moped engine and i need to replace the piston rings. i measured one of the existing rings and it reads about 41mm in diameter. I went to the website of the company and found all the technical information about the moped and it said the piston ring diameter was 32 x 2 as you can see in the first picture. I don't know what units they are using and I cannot order the exact parts online because the company went out of business. The company is called JAWA and is from Europe. I need the correct measurements of the ring so i can order a new one. 32 x 2 is the only information given and if that is in millimeters, then it argues with my 41mm reading of the ring diameter (it is most likely not exactly 41mm but i don't have the correct tools to measure accurately). Are they measuring it a different way? Please tell me what i should do when trying to order replacing piston rings. I was thinking of using rings used for chainsaws. The cylinder has not been re bored. Also, on the second picture i do not understand why there is "A,B,and C" measurements of the same piston? Please help me.