The titanium intake valves are 2.5mm larger, while the exhaust valves are 1.0 mm larger. The intake valves have 1.3mm more lift, while the exhaust valve lift is 1.1mm higher. The valve’s V-angle is narrower at 20.5 degreed. The cylinder is offset 4.5mm forward of the centerline (it was 4.0mm forward in 2017).
Nobody likes to be considered to be among the slowest bikes on the track, least of all Honda. But, when CRF250 sales dipped 27% in 2017. Honda was ready to retire the old warhorse. Luckily, Honda had an all-new bike waiting in the wings for 2018. How new? It shares almost nothing with the 2017 CRF250 and almost everything with the 2018 CRF450.