Motorcycle casing cylinder ,means the whole cylinder set ,including three parts: cylinder,piston,piston ring ,some including piston pin.Generally when the motorcycle appears rising of oil consumption ,it's better to change the whole casing cylinder,piston and piston ring,only to change one part the effect will not be good,maybe only can last short time then will happen again the rising of oil consumption ,instead,changing the whole set ,all parts are matched perfectly ,will almost be impossible to cause the error.