Round one of the All Japan National MX Championship Series got underway today at Kyushu MX Park in Kumamoto, Japan, and we got to check out what could very well be a pre-production 2014 Yamaha YZ450F. We first got wind of Yamaha changing the engine location and angle in the chassis when both FMF and DRD began to produce the race-team-only wrap-around exhaust systems for the JGR Yamaha and N-Fab Yamaha teams, respectively. Piloted by Takase Tanaka and Yu Hirata, the YZ450Fs we saw in action today didn’t have the polished, early production look that the Honda CRF250R did. Parts of the airbox and radiator cowling looked hand-made, and furthermore; the hidden gas tank cap seems a bit radical for production. Though we do believe much of these two race bikes to be a preview of what’s in store in 2014, we wouldn’t be surprised to see a different gas cap configuration when the production machines arrive.