# Piston rings on a 50cc moped engine



## xxironchefxx (Aug 9, 2008)

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.

http://img354.imageshack.us/img354/838/123he8.png
http://img125.imageshack.us/img125/1053/1234vt8.png


----------



## BDM53 (Aug 9, 2008)

If you can borrow a set of mics, measure the bore, the piston and the ring thickness. I think there was something else buts it been awhile and I am by no means a machinist. They told me what to measure and you will need an acurate measurment. You may be able to find something off their website too. Weisco may have something that will fit. I have ordered rings from them for an Alpha Sports 50 a couple of years ago and they had them. Just a thought, hope it helps.


----------

