Here you will find all cylinder gasket kits for Naraku 4-stroke cylinders for 139QMB/QMA engines, KYMCO 50cc 4-stroke engine or Chinese original and tuning cylinders, 39mm - 52.4mm bore size The gasket kits consist of: cylinder, cylinder head gasket, exhaust manifold gasket and timing chain tensioner gasket. Please find the appropriate size by looking at the list below.