

THE 2023 YAMAHA MX MACHINES THAT GOT LOST IN THE YZ450F HUBBUBĢ023 YAMAHA YZ250F: The 250cc four-stroke engine features aggressive cam profiles and a reversed cylinder head layout.THIS WEEK AT MXA: BARCIA VS FERRANDIS - WHO’S IN THE WRONG? JUSTIN, DYLAN OR MXSPORTS?.
KAWASAKI RACE GEAR PLUS
(15) The new footpeg design is 5mm wider front-to-rear and 3mm rearward, plus the footpegs are now mounted on aluminum instead of steel brackets. (14) The rear shock also has firmer compression damping. (13) The fork valving is changed to deliver firmer compression damping, while the fork spring rate is unchanged, the revised oil height contributes to the firmer feel. (12) Intake duct angle optimized for a straighter approach for intake air. (11) Tapered intake funnel contributes to top-end performance. (10) The downstream injector located on the bottom of the intake duct for quick throttle response, while the position and angle the upstream injector matches the airbox design to contribute to top-end performance. The second gear ratio was also fine-tuned to offer a smooth transition from first to third gear. (9) The 2023 Kawasaki KX250 has a longer first gear that makes it easier to use in more situations. (8) Connecting rod big-end bearing crush height was increased for more durability. (7) Revised clutch pushrod helps provide lighter clutch operation. (6) The magneto rotor has an increased moment of inertia to smooth out the power delivery. (5) The exhaust system features a 100mm longer header pipe for increased low-mid range torque. (4) The downdraft-style intake duct is straighter, and the upstream injector is repositioned to the underside of the duct to further contribute to increased performance. (3) Piston crown was revised to match the new valve size and pitch changes. (2) The 31mm intake valves are 1mm smaller than in 2022, which contributes to cylinder-head/valve-seat reliability. (1) The 2023 KX250 intake valve pitch is reduced from 37mm to 35.5mm, coupled with increased clearance at the valve seats, this helps deliver increased cylinder-filling efficiency and improved combustion for increased peak performance.

