The engine may look the same from the outside, but significant changes lie inside—the most significant being the valves are now actuated by finger-followers, more aggressive camshaft profiles, larger valves, a 1mm larger bore, 1.4mm less stroke, a 1mm larger throttle body, a revised piston crown for increased compression, and a shorter intake funnel. Also, Kawasaki informed us the rev limit has been increased by 650 rpm over last year’s model.
When kickstarting the bike, we noticed it required a more forceful kick compared to the 2019 model, most likely due to the increased compression. The bike still kicks fairly easily, but we noted it took a few extra kicks to fire to life once it got hot. The engine retains the crisp power delivery and good midrange of the prior bike, but pulls noticeably harder and longer on the top-end, which enables the rider to hold a gear longer and without the need to shift excessively to keep the bike in the meat of the powerband, as was the case with last year’s model. With the meat of the powerband being shifted higher in the rpm range, we noticed the new KX250 has slightly less bottom-end power, but it’s more than a worthwhile trade-off for the newfound high-rpm pulling power. The green machine retains its easy clutch pull too.