Some might say that two-stroke dirt bikes are dead and buried, but KTM says “Not Yet!” to that and offers a great model to back up their affirmation – the 2009 KTM 250 SX. This bike is keen on providing the demanding two-stroke crowd with loads of torque, defining a unique powerband as well as sound and smell, all contributing to the unmistakable riding experience.
Because we’re talking about old technology here, there isn’t much to improve, but definitely everything to enjoy. The two-stroke engine is the one providing all the satisfaction and in this case we’re talking about a liquid-cooled 249 cc, single-cylinder unit featuring TVC power valve. The Keihin PWK 36 S AG carburetor needs to do double the work than in the case of four-stroke engines as two-strokes provide a bang each time the piston reaches its highest traveling point so that’s basically a bulletproof unit right there. Two-stroke engines are usually kick started and this one makes no exception. The rider would have to go through the choke pulling and lever actuating routine without forgetting to open the throttle a little bit in order to ensure quick starts each and every time. All this adds a certain something to the bike’s unique character and at it being carried on as a new model year.
While the engine isn’t the latest thing in the domain, the chassis is. In fact, we’re looking at a 2009 SX-F chassis on which another engine was mounted for greater rider excitement. The frame is the same double-cradle-type 25CrMo4 one while the subframe and Renthal handlebars are made out of aluminum. Definitely the best of it are the suspensions – 48 mm WP USD fork capable of 11.81 inches of wheel travel and WP PDS shock absorber offering 13.19 inches of wheel travel. Working with 21-inch front and 19-inch rear Excel wheels, this contributes at making the bike a sweet corner carver and good at jumping too.
KTM does place it in their Off-Road Competition lineup, but this is a veritable motocrosser fitted with five-speed transmission and being very light (only 208 lbs. with no fuel), but still robust and very reliable. The 15.16 inches of ground clearance are more than plenty to work with and this has also much to do with the 38.78 inches high seat, which is this bike’s biggest disadvantage.
Two-stroke dirt bikes are a rare breed nowadays, but, like KTM, Husqvarna still has a decent market to sell these things on so they carry on producing their two-stroke model range where you’ll also find the WR 250 . This bike is very similar to the Austrian one, but features a headlight and it is called an enduro. That’s just not fair!
Among the Japanese crowd, Yamaha is the only manufacturer still making two-strokes and the YZ250 is the corresponsive model in this case. Now this is a motocrosser in all of its aspects so follow the previous link to find out more about it.
KTM offers no Six Days version for the quarter-liter SX, just their base 2009 color scheme on the aggressive bodywork with no features shared with any of its off-road siblings. To begin with, the fenders are mounted high above the Excel wheels, which feature black paint. Being orange, the fenders contrast nicely with the large-diameter dirt spreaders positioned 58.07 inches apart one from the other. While we’re talking about dirt, it’s worth mentioning the black mudguards and that’s pretty much it. Hand guards are available only as an option.
Unlike Husky, KTM mounts a number plate instead of a small headlight in order to enhance the aggressive note of this bike. But it’s not all in the looks. The seat is narrow and the gas tank positioned well down into the frame. Underneath the tank, the two-stroke torque and power supplier is distinguished due to the decently sized exhaust pipe, a characteristic of the respective engine type.
It’s hard not to notice the Renthal handlebars, petal-style discs and long swingarm, but the side plates give that final touch which makes the bike easily recognizable from a first glance.
Although offering better performance than any of the 250 cc four-strokes out there, the 2009 KTM 250 SX starts at $6,598, which is under the pricing range of that motorcycle category.
With the 2009 quarter-liter SX, KTM shows how things can be pushed even further in the case of two-strokes not necessarily with engine performance, but by making use of a modern chassis that is light, refined and makes the bike flick able and allows the rider to get the best out of it both on and off the track.
Engine and Transmission
Engine type: Single cylinder, 2-stroke
Displacement: 249 cc
Bore x stroke: 66.4 x 72 mm (2.61 x 2.83")
Transmission: 5 gears
Carburetor: Keihin PWK 36 S AG
Control: TVC power valve
Lubrication: Mixture oil lubrication 1:60
Transmission oil: Motorex, SAE 15W50
Primary drive: 26:72
Final drive: 13:48
Cooling: Liquid cooled
Clutch: Wet multi-disc clutch, operated hydraulically
Chassis and Dimensions
Frame: Central double-cradle-type 25CrMo4
Handlebar: Renthal, Aluminium Ø 28/22 mm (1.10/0.87")
Front suspension: WP USD Ø 48 mm (1.89")
Rear suspension: WP PDS shock absorber
Suspension travel front/rear: 300 / 335 mm (11.81 / 13.19")
Brakes, front/rear: Disc brakes 260 / 220 mm (10.24 / 8.66")
Rims, front/rear: 1.60 x 21"; 2.15 x 19" Excel
Tires, front/rear: 80/100-21"; 110/90-19"
Chain: 5/8 x 1/4"
Main silencer: Aluminium
Steering head angle: 63.5°
Wheel base: 1475 ± 10 mm (58.07 ± 0.39")
Ground clearance (unloaded): 385 mm (15.16")
Seat height: 985 mm (38.78")
Tank capacity: approx. 8 liters (2.11 gal)
Weight (no fuel): approx. 95.4 kg (208 lbs)