the 2013 KX250F does, in fact, have a shopping cart full of updates. Kawasaki focused on 11 areas of concern. (1) Engine. A new intake tract provides a straighter path to the engine, houses the air temperature sensor in a different position, improves shielding for the upstream fuel injector and is easier to install. Due to the revised intake tract, the cylinder head intake routing was also changed (with a focus on “downdraft” flow). The intake valve seats are steel and allow for improved long-term engine performance. The intake cam timing was retarded by 4 degrees for increased high-rpm power. Other changes include a repositioned upstream fuel injector that is also rotated for greater power optimization. The throttle position sensor (TPS), idle knob and fuel-line fitting have been revised to improve durability, as well as ease adjustment. A shorter cylinder head (by 0.10mm) increases the compression ratio (from 13.5:1 to 13.8:1) for improved bottom-end performance. The bridged-box piston’s skirt has a softer arc area for improved durability, and the spark-plug cap offers a tighter seal. Kawasaki also increased the inertia of the ignition rotor for enhanced traction. ( 2) Exhaust. Add the KX250F to the growing list of bikes that come with a resonance chamber. The advantages of a resonance chamber include increased bottom-end performance without affecting top-end power and quieter acoustics. The exhaust is still made of stain- less steel. As for the muffler, the canister length has been shortened by 30mm and has 12.5mm more girth. The outlet diameter is 7mm wider for improved flow characteristics. In case you’re wondering, last year’s exhaust system will fit on the new bike. ( 3) Map couplers. Just as with the KX450F, the KX250F comes with three interchangeable coupler caps. The couplers are color-coded (green=standard, white=aggressive, black=soft) and change engine performance. Located on the steering head, the couplers can be switched out in less than 30 seconds. ( 4) Chassis. A carryover concept from the KX450F last year, the new KX250F frame is 4mm narrower for improved feel and slimmer ergonomics (the KX250F frame is different from the KX450F chassis). Rigidity has been increased in the steering head and shock tower, as well as the upper engine mount. The lower triple clamp now opens from the rear (as opposed to the side as in years past) for greater rigidity, and the bolt holes are on the sides of the clamp (instead of the front). ( 5) Swingarm. A new swingarm is 20mm longer and offers up to 4. 2 percent more torsional rigidity and enhanced durability. The twin, tapered, hydroformed spars feature a natural aluminum finish to help maintain appearance, and the chain adjusters are forged for maximum precision. ( 6) Forks. The KX250F still comes with Showa’s Separate Function Fork (SFF), but the fork tubes are larger (48mm). The axle lugs have been redesigned, and the fork’s preload adjuster uses a 17mm wrench (instead of 21mm) for easier access. Regarding the preload adjuster, four clicks now equate to 1mm of preload (the
2013 KX250F: This isn’t a carryover model from last year.
Kawasaki refined an already excellent bike by using a
narrower frame, new swingarm, and an exhaust system with
a resonance chamber (among other things).