... and cylinder sleeve is made of boron iron cast with aluminum penetrated on surface.Cylinder housing is processed by high pressure ... (PULSAR, BOXER, etc.) ,TVS, HARLEY DAVISION, VESPA, SYM, China made scooter, LIFAN, HAOJUE, JINCHENG, QJIANG, YINXIANG, BAOTIAN, ZONGSHENG, DAYANG, LONCIN,JIALING ... our long term business relationship! GY6-50 cylinder head,scooter parts Cylinder head,scooter engine parts