$2,999
Denton, Texas
Category
Dirt Bikes
Engine
-
Posted Over 1 Month
2006 Honda CRF 250X, Technology straight from the CRF250R this high performance off road dirtbike is ready to hand anything!!2006 Honda CRF250X Like the CRF250R, the CRF250X incorporates a new-generation four-stroke Unicam(R) single-cylinder engine, one designed to run at speeds in excess of 12,000 rpm. That engine speed, for the record, is faster than the majority of high-tech street machines. Like the motocrosser, the 250X engine is also cradled within a new, fourth-generation aluminum frame equipped with top-drawer suspension and chassis components. No corners have been cut here; in fact, extra R&D effort was spent in retuning the entire chassis to suit off-road needs virtually to perfection. In like manner, the engine faithfully follows CRF-R architecture, but the 250X incorporates modifications that make it even better suited to serious off-road work. Establishing the state of the art in off-road engines The CRF250X engine features forked rocker arms that actuate two lightweight and very tough 31mm titanium intake valves, which feature a special surface processing. The two 26mm exhaust valves are made of high-temperature steel with heat-resistant Inconel(R) alloy used in the neck area just before the flare of the valve head. Inconel alloys contain high levels of nickel and can be thought of as super-stainless steels that have exceptional anti-corrosion and heat-resistance properties. Like the CRF250R, the 250X incorporates a compression ratio set at an extremely high 12.5:1. This creates a piston with a relatively tall dome, but overall the 250 piston height is very low and its skirt is ultra-short, so instead of looking like a piston used in run-of-the mill four-stroke engines, it looks more like a piston crown with wrist-pin bosses. The amazingly short and narrow piston skirts come from the factory impregnated with low-friction molybdenum to ensure a smooth piston-to-cylinder fit beginning with first use. The forged piston runs in a cylinder made with a tough, low-friction Nikasil(R) liner, a setup that also enhances cooling and reduces weight because it eliminates the need for a separate cylinder liner. In addition, the 250 s connecting rod is double-carburized for extra toughness, and it utilizes a needle bearing in the big end to maximize high-rpm performance and increase durability. Likewise, the high-strength, low-carbon steel crankshaft features carburized main journals for maximum durability under high engine speeds. In keeping with CRF-R engine design, the 250X incorporates a twin-sump lubrication system that separates the engine oil from the oil bathing the clutch and the wide-ratio five-speed transmission. This dual-supply system ensures a cooler environment for the clutch, while also isolating the engine from any potential contamination caused by clutch and transmission material. Because the total volume of oil circulating to the crankshaft, piston and valve train has been reduced, the
