2019 KTM 450 XC-F. When maximum attack is required, the only answer is the 450 XC-F. The compact SOHC engine delivers explosive power in a smooth, usable delivery that suits both weekend riders and seasoned racers alike. More to the point, the 2019 450 XC-F shares 95% of its parts with the multiple championship winning 450 SX-F motocross bike. KTM 450 EXC-F. The big news for two-stroke devotees is the move from Transfer Port Injection, introduced in 2017, to the 39 mm Keihin Throttle Body Injection system used for the last few years by qHWXeLd.