Since 2018 will be Yamaha’s last year of its YZ450F producing cycle this may very well be the updated bike. Notice there is no sign of a kickstarter and the frame is vastly different. 

We found a press release on the Japan Yamaha website (in Japanese) of their new team for the 2017 year for the All Japan Nationals. The riders are Hirata Yu riding on the factory YZ450FM and Yusuke Watanabe aboard the YZ250FM. If you look at these bikes closely, especially the YZ450FM, you can see some big variances between the 2017 and the factory  model YZ450F.

2018 YZ450FJapan rider, Hirata Yu will be racing this full factory bike in the All Japan Nationals. 

Since 2018 should be the end of  Yamaha’s rigid four year production cycle of the YZ450F, this may very be the meat and trimmings of the production 2018 YZ450F. Look closely at the frame, body work and electric start. Although Yamaha has been tricking us for years that an electric starter will come on the production model. We won’t get our hopes up.

2018 YZ250FThis is Yusuke Watanabe YZ250FM for the 2017 All Japan Nationals. Notice the aluminum tank. 

2018 YZ250FThe 2018 YZ250F will only have small revisions or none at all as it will get whatever the big 2018 YZ450F updates are for 2019.