2002 KX250 Key features and changes
Engine: Reshaped porting for more power throughout the rev range and better over-rev power; New two-piece power valve with increased valve width, and new spring and lever shape for better sealing and increased mid-range power; Piston skirt lengthened for better exhaust-port sealing; Connecting rod redesigned to allow more oil into the big-end bearing for improved durability and with smoother finish for unimpeded oil flow; Increased outer diameter of main bearing; Increased diameter of kickstart shaft, which is now mounted on an involute spline; Crankcase modified and outer diameter of the bearing increased to maintain clearance between connecting rod and cases; Governor assembly and spring modified to complement gear ratio modifications and larger kickstart shaft
Ignition: New twin-spark system produces two overlapping sparks for longer intervals at lower rpm for improved power and torque from ultra-low rpm through the mid-range; New iridium sparkplug increases spark energy to enhance performance and over-rev; New 16-bit processor accommodates new system and modified ignition timing; Rotor incorporates vent holes to improve cooling
Keihin Power Jet PWK38S carburettor: " Shorty " design places the main jet and slide close to the cylinder for improved throttle response; Kawasaki Throttle Responsive Ignition Control (K-TRIC) uses a sensor to alter ignition timing according to throttle position and engine speed for better throttle response and more power; Power Jet system uses an electronic solenoid to close a fuel passageway according to rpm and throttle position for crisp jetting and increased top-end power at over-rev.
Exhaust: O-rings are thicker, retention spring is longer and a plate has been added to the exhaust pipe mount for better sealing.
Gearbox: Second through fifth gear ratios changed for better and smoother power delivery; Gear tooth valleys changed from rounded to squared for increased contact; Primary gear altered to complement new transmission gear ratios
Rear suspension: Cast-aluminium section of the swingarm is designed for less unsprung weight and more rigidity; Shock features both low- and high-speed compression-damping adjustments.
Front suspension: 48mm USD forks; Inner fork tube diameter increased for more rigidity; Tube thickness decreased for weight loss
Brakes: Front brake caliper’s twin pistons made from aluminium to reduce weight; Rear brake master cylinder incorporates new push rod for improved pedal position
Steel perimeter frame: Features new footpegs to reduce mud build-up; Removable aluminium rear sub-frame for easy access to the rear shock
Details: New graphics; Reshaped seat to increase airflow around airbox; Flatter fuel tank incorporates new square inset nuts where the shrouds and seat base mount for security; Revised side covers complement new seat and tank; New handlebar bend is 10mm taller and 10mm straighter; New chain and chain roller with bearing to reduce weight and increase durability; Optional 20-inch rim or wheel assemblies available; Aluminium clutch cable adjustor replaces old steel unit to reduce weight