Kawasaki KX 250 Top Speed, Specs and Features (Explained)

For years, the Kawasaki KX 250 has been one of the most dependable workhorses and motocross racing leaders. Light and fast, the KX 250 is built to take on all terrain, and it stands out on the track with its race-bred suspensions and aggressive geometry.

With dual compression adjustability, knobby tires, and racing-grade wheels from Kawasaki’s factory racing team, the KX 250 is geared towards dirt-racing enthusiasts. And in testament to its reliability, the bike reigned supreme in motocross, winning the world championship a whopping ten times.

But is the latest KX 250 as good as it always has been? Is it still worthy of its legendary reputation for its unsurpassed handling, or is it time for a change? As we explore these questions in this article, we’ll look at the KX 250 at length, discuss its key specs and features, and common queries that tag along.

About Kawasaki KX 250

Kawasaki’s KX 250 has been around since 1974, and it’s one of the best-selling small motocross bikes in the United States. It is one of the most loved bikes in the motocross world, even today, thanks to its lightweight, powerful four-stroke engine and phenomenal handling.

Notably, the KX 250 has a reputation for finishing races on top and winning championships at every level. In fact, it has won two AMA Supercross and Motocross championships.

Dirt riders frequently praise its excellent handling, mainly because of its frame geometry, which is exceptionally rigid yet remarkably lightweight due to its single backbone design and high-tensile steel. Consequently, it allows you to make quick transitions through bumps and corners, something that can’t be said about many other motocross bikes out there today.

Engineers at Kawasaki have tweaked the engine over the years with new features added in each model year for more power or better reliability (or both).

These changes include reed valve spacer plates that help airflow into the cylinder and reshaping exhaust ports for better low RPM torque. They also added fuel injection in 2004 to help keep emissions down and an ignition system that can adjust timing based on the rider’s RPM and throttle position sensor inputs.

Kawasaki KX 250 Specs and Features:

Kawasaki’s KX 250 has seen several versions over the years, each adding one or more new features over the previous model. Below is an overview of the key features of the KX 250’s latest baseline model.

Engine

The 249cc liquid-cooled DOHC 4-stroke engine produces smooth power across the rev range, with a power output ranging from 6,300 rpm to 13,000 rpm and maximum rear-wheel torque of 18.38 lb-ft at 9,440 rpm. The engine features a piston skirt coating for better durability, a connecting rod for increased strength and reduced weight, and an improved lightweight piston.

Ignition

The KX250 features a digital CDI ignition with a digital AC-CDI system that delivers more consistent and powerful sparks. Digital CDI systems also allow for smoother revs and improved combustion efficiency, which gives the rider a better throttle response. The system is also more reliable, as a digital CDI box is less prone to damage from water than its analog counterpart.

Transmission and Drivetrain

The transmission on the KX250 has a five-speed cable-operated gearbox. This bike’s clutch consists of a wet multi-plate design that allows smooth shifting and easy operation. The cable-operated system has six friction plates and two steel plates for better heat dissipation. The KX250’s final drive uses a 520-pitch, 120-link chain.

Brakes

Both front and rear brakes on the KX 250 are disc brakes. The front disc consists of two hydraulic discs in contrast to the rear’s one.

Two independent hydraulic circuits actuate the front brakes with an anti-lock braking system (ABS) as standard equipment. The ABS monitors wheel speed, and if it detects that one wheel is about to lock up under braking, it automatically reduces the brake pressure for that wheel to allow it to turn again.

Suspensions

Its front suspension is a 48 mm inverted Showa cartridge fork with 16-position compression damping adjustment and 12-position rebound damping adjustment. The rear’s New Uni-Trak shock has dual compression adjustability with rebound damping and spring preload via the linkage system.

Wheels and Tires

The KX250 wheels are lightweight and robust, with a front hub 15mm smaller in diameter than its discontinued predecessor. The rear hub is also smaller and lighter, and the spokes were changed from two- to three-cross. The aluminum alloy rims are made by Excel, the same company that manufactures hubs for Kawasaki’s factory racing team.

The KX250 comes standard with Dunlop D756 tires. These knobby tires are 2.75 inches wide in the front and 4.5 inches wide in the rear and designed for off-road racing but also suitable for street use.

Dimensions

The Kawasaki KX 250 sets itself apart from other motocross bikes for its 85.8 inches overall length. The bike’s height is 49.8 inches from its bottom to the top of its handlebars. It measures 32.3 inches wide and has a wheelbase of 1,485 mm. The ground clearance is 13.2 in, and its turning radius is 3.8 m. The seat height is 37.4 inches, its dry weight is 226.4 lbs, and it has a fuel capacity of 1.64 gals.

Exterior

The new KX 250 features an all-new frame and swingarm for improved handling and straight-line stability. Its stiff, rigid structure features a reinforced steering head tube, broad front section with tapered edges, upsized main-spar cross-section, gussetless design in the lower cross member, and increased thickness in the central perimeter spars.

Dual Injectors

The KX250F features two injector settings and is the only production motocross bike with this technology. Using this technology, you can use a richer or leaner strategy for different riding conditions by switching the fuel injection mapping. This feature helps deliver optimum performance from the Keihin DFI 44mm throttle body.

KLCM (Kawasaki Launch Control Mode)

New for 2014, the KX250F features a Launch Control Mode that maintains engine revs at 9,000 rpm during starts. By controlling the engine output during take-off, the KX250F rider can concentrate on finding traction from the rear wheel. After reaching the second gear, the Launch Control Mode is canceled, and the engine returns to its normal operating mode.

ERGO-FIT Chassis Management Technology

The KX250 motorcycle features three adjustable footpegs positions, four ergonomically-positioned handlebar positions, and three easily adjustable handlebar mount positions. This wide range of adjustability options allows riders of all sizes to optimize the fit of their racer.

Kawasaki KX 250 Top Speed

The Kawasaki KX 250 is considered a high-revving motocross bike with a top speed of around 87 mph. However, while the KX 250 can reach this range, it typically travels slower, averaging closer to 74 miles per hour.

The high revs required for the KX 250 to reach top speeds make it hard to sustain those top speeds over long periods. Besides, it can fluctuate depending on several factors, including the rider’s weight and how much gas is in the tank at any given time. The latter is often the case since the fuel tank doesn’t hold much.

If you’re an average-sized person and you tend to ride on flat surfaces or with a full tank, then it’s likely that your top speed will be somewhere in the 71 miles per hour range. However, if you weigh more than 200 pounds or ride uphill often with little fuel remaining, you can expect to see lower speeds in excess of 62 miles per hour.

Overall this bike is a good option for beginners who don’t need anything fancy but still want fun. It’s not as flashy as some of Kawasaki’s newer models, like their KLX 450R or KX 450F in terms of speed, but it runs well enough that most dirt riders will be satisfied with.

How to Increase the KX 250 Top Speed?

The KX 250 is intended to be light and fast, enabling it to perform well at high speeds. However, your KX 250 may feel underpowered when you are not on track.

But you can increase the top speed of your KX 250 through a few different methods without sacrificing too much performance or spending a lot of money. Here are a few practical suggestions.

Alter the Gear Ratio

If possible, change the gear ratio on your rear sprocket by adding one or two teeth to it. Doing so will increase acceleration and allow you to shift into higher gears sooner. If you have already increased the number of teeth on the sprocket to its maximum amount, try an aluminum sprocket rather than steel, as aluminum is lighter and will reduce rotating weight.

Add a Turbocharger

Turbocharging your KX 250 will definitely increase your top speed, but it can be expensive and time-consuming (and possibly void your warranty). If you’re handy with tools, you can try adding a turbocharger yourself.

A turbocharger works by compressing air before it enters the engine intake manifold. Meaning more air can enter the cylinders during each combustion cycle in the engine, which results in more power and speed. However, this technique is very energy-intensive, so you need to be careful not to destroy it by overloading it.

Replace the Stock Muffler

Replace the stock muffler with an aftermarket exhaust system that offers less back pressure than stock systems. More back pressure slows down engine performance and decreases top speed; reducing back pressure by installing a different exhaust system will increase engine efficiency and boost your top speed.

De-Restrict the CDI Unit

The CDI unit (capacitive discharge ignition) on your KX 250 limits the engine’s revs and reduces the available power from the engine. By de-restricting this unit, you will obtain more power from your machine, allowing it to reach a higher maximum speed.

Remove the CDI unit from the bike and take it apart. Inside you will find a green wire typically used for speed limiting. Snip it and replace the CDI unit without the limiting feature. This mod can give you about a five mph increase in top speed.

Install a More Aggressive Chain

A stock chain on a KX 250 should meet most riders’ needs and situations, but it won’t give you maximum acceleration or top-end speed. You can improve both by installing a more aggressive chain with less friction. The best way to make this change is to buy a new chain and sprocket kit that matches the needs of your bike and riding style.

Kawasaki KX 250 – Pros and Cons:

The KX 250 is a great bike that fits the bill for many riders, but it is not without its faults. Let’s look at some pros and cons of this widely-used motocross dirt bike.

Pros

  • Unmatched Handling: KX 250’s updated frame and suspension provide an unsurpassed solid feel on the track. Its aluminum perimeter frame is lighter and more rigid than the previous edition, and the inverted Showa cartridge forks are plusher with better bottoming resistance. The rear shock is also new for 2015, tuned to be slightly softer than previous versions.

The minor differences in the suspension setup make a big difference; you can hammer into turns harder and faster than before, knowing that if you mess up your line, you won’t get thrown off balance from the bump.

  • Rider Focused Ergo-Fit Chassis: The KX250 is Kawasaki’s answer to being more ergonomically friendly to the smaller rider. The Ergo-Fit chassis is a new subframe, footpegs, handlebar, seat, and radiator shrouds that all combine to give the bike a smaller feel. In short, the purpose is to make it easier for riders of all sizes to maneuver the bike.
  • Engine and Tuning: The KX250’s 250cc 2-stroke engine boasts four titanium valves. As far as tuning goes, you have adjustable compression damping and rebound damping on the forks and shock absorbers. You also have triple clamp offset options and a choice of triple clamps for an authentic enduro feel.
  • Launch Control Mode: Launch control mode can help riders maintain traction during hard starts, particularly on slippery surfaces. The system is concealed within the bike’s ECU and can be activated through the handlebar switch while pushing the start button. Once activated, it will limit engine rpm to approximately 9000 rpm until the rider shifts into second gear.
  • Updates Galore: Kawasaki had done a thorough job refreshing its flagship motocross machine for the new decade. More than 50 percent of the bike was redesigned, with the most significant changes being the chassis. The frame is all-new, with an aluminum subframe replacing steel. Furthermore, the engine received new cylinder heads, pistons, crankshafts, and more—a true delight for loyal KX 250 enthusiasts.

Cons

  • Powerband: The KX 250’s new engine makes more power than ever before, but it’s challenging to find a smooth powerband in any of the six gears. There are three modes—soft, medium, and hard—but none of them offers a sweet spot where the motor pulls strong without being jerky or peaky. You end up feeling like you have to wrestle with the throttle all race long to get anything out of it.
  • Wear-Prone Chain Roller: The chain roller on the 2006 KX 250 tends to wear down more quickly when used in dusty environments, causing it to need replacement more frequently than other parts on the bike. Hence, if regularly used, this can be an expensive problem.
  • Noise: The bike is loud, like several other bikes in its class. It has a high decibel level throughout the entire rpm range, unforgiving of rider errors as it does not absorb track imperfections well.

FAQs.

How much does a KX 250 cost?

The cost of a KX 250 is approximately $7,799. The price can change depending on the year of manufacture, but the cost has remained around $7,500 in recent years.

Is a Kawasaki KX250 a 2-stroke?

No, the latest KX250 is a 4-stroke. Kawasaki discontinued the 2-stroke design after 2008.

Is the KX 250 a good bike?

The Kawasaki KX 250 is an excellent bike for beginners and professional racers. It has impressive power and feels great on the track or in the woods. The KX has a smooth power delivery with easy-to-use controls.

What does a 2021 KX250 weigh?

The official curb weight of the 2021 KX250 is 226.4 pounds, which can go up to 237 pounds with fuel.

Does Kawasaki still make KX 250 dirt bikes?

Yes, the Kawasaki KX 250 is still in production. However, the original 2-stroke version has been no longer available since 2008.

What are the height and weight of KX 250?

The bike’s height is 49.8 inches from its bottom to the top of its handlebars. Fueled up, the KX250 can weigh 237 pounds, but its official curb weight is 226.4 pounds.

Conclusion

Is the KX 250 worth a purchase now, or is it time to make a change?

The fact is, it’s hard to say. The KX 250 holds a lot of prestige and is backed by proven performance. Its dependability and durability are unparalleled in the motocross race world.

However, we can look forward to some changes in 2022 and beyond. Right now, the Kawasaki KX 250 looks like it could stick around for another five years or more.

Yet, even today, it stands out as the go-to choice for novice and mid-level riders who want the best of the best.

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