I have the Zeda 80 triple 40. one of the piston rings broke and I need a replacement. I bought a pair on Amazon that said they were for the 40mm piston. I got them today and they are too small if I try to stretch them over the top of the piston they will break. Does this motor come with a diffterent piston size than advertised? What size do I need? Can someone post a few links for an exact replacement? Thanks!