2010 Kawasaki KX250F First Ride

n the ultra-competitive realm of 250F motocross racing every second counts and sometimes the brand of motorcycle can be the difference between winning and losing. That’s why manufactures tweak motocross bikes each year in an effort to put you out front. This year’s KX-F received a complete makeover from the wheels up (read about it here in our 2009 Kawasaki KX250F First Ride), so for ’10 engineers focused on tweaking its existing platform giving us the 2010 Kawasaki KX250F.

Powertrain Updates
The new quarter-liter KX-F sports a host of changes to both its engine and chassis enabling you to scoot around faster than before. Perhaps the biggest news is that the new KX250F will not be equipped with electronic fuel-injection. Instead it’s fitted with the same mechanical 37mm Keihin carburetor as last year.

Although it looks virtually the same, the engine sports different cases designed for increased durability. Inside, a new piston slides within a 0.5mm taller cylinder that uses new cylinder bore treatment for smoother action. Not only is the piston lighter, it’s taller, hence the reason for the taller cylinder, and the 13.2:1 compression ratio remains the same. It also utilizes a shorter skirt and a much narrower piston pin area. Kawasaki claims these updates allow the engine to rev faster and harder through its 13,400 rpm range. Although the engine’s four-valve DOHC cylinder head remains the same, the intake camshaft holds the cylinder decompression on longer allowing for easier starting.

Looks can be deceiving. Although it appears unchanged, the 2010 KX250F employs engine and chassis updates for improved performance and durability.

By Adam Waheed of motorcycle-usa