The 138190057 M8 Exhaust Nut secures stock or aftermarket exhaust systems to the exhaust studs. 

The factory nut must be doubled or the studs must-have safety wire for most kart tracks as a preventive measure if the nuts or bolts were to back out and the exhaust comes off the engine. 

The Exhaust Nut fits most of the 196cc 6.5hp Clone Exhaust Studs including Honda GX200, Ducar 196, Ducar/Tillotson 212E, Tillotson 196R/RS, Tillotson 212R, Ducar/Tillotson 212E, Tillotson 225RS, Predator 212 and BSP 196 and 212 Engines