- Single cylinder, 2-stroke
- 6 gears
- Keihin PWK 38 Carburetor
- 143.6cc L
- Top Speed:
- 110 mph
The tract is its middle name as it was born there and it is also where it likes to spend most of its time. The 2008 KTM 144 SX is small, agile, a real powerhorse from KTM, and manages to effectively deliver its power to the rear wheel and blow away the competition.
KTM is famous for delivering impressive performing two-stroke motorcycles, but this is very often more than riders expected. The 144 SX is characterized by its awesome power output and superior handling which always combine in the most effective way and have this two-stroker rev its way first to the finish line.
Success won’t come at a cost as the maintenance costs are reduced to a minimum by the rewarding Austrian manufacturer.
Given to its type of engine and its displacement, the KTM 144 SX is hard to be put up against a direct competitor because nobody on the market offers diversity at the level that KTM does.
You will find it easy to compare it with the usual Japanese two-stroke 125cc motorcycles (Honda CR125R, Yamaha YZ125, Suzuki RM125), but that’s where the KTM 125 SX enters the scene and claims its fair share of competition so where could the 144 SX head? I would definitely love to see KTM’s competition eating dirt, but who’s that competition? I guess this bike will only compete in the AMA amateur MX Lites race class.
It might be positioned in a class of its own by the 144cc motor, but this bike looks like the motocrosser you’ve always craved about. Its front end is being dominated by the Orange fender and number plate which are stylish and aggressive and create an impressive visual contrast with the black Excel rims, fork and mudguards.
The handlebars occupy a high position and are orientated towards the rider for a better feel and control over the bike and offer a relaxed riding position. Also for that purpose, the seat is narrow, positioning the spoiled rider in the best and recommended spot on the bike’s saddle.
What definitely determines people to call it beautiful is the sharply-styled side panels covered in Orange decals and the white “KTM” writing on both sides. Things keep the same rhythm all the way to the bike’s rear end which is dominated by the high rear fender and the lateral number plates.
The 144 SX seems practically like a bigger bore and stroke 125 SX (56 x 58.5mm bore and stroke, instead of 54 x 54.5 on the 125) so you would expect the bike to perform virtually the same with a little bit more power all the way up and down its powerband. But the 144 SX was built for the competition and KTM made no concessions when it came to this single cylinder, two stroke engine which is what comes different from the 125SX. A different cylinder, piston, crankshaft, centrifugal power valve, CDI unit and exhaust pipe all contribute to do the trick on this brand new model.
What immediately strikes you when getting on a KTM 144 SX and twisting is throttle is the incredible power available, especially in the mid-range. This was the key when KTM tuned the engine as a wide powerband results in a more potent mid-range for fast passing competition on the motocross track.
No lacks of power will make your ride feel weak because al across the powerband, the bragged two-stroke motor has an ace in its sleeve and it shows it every time you challenge a 250cc four-stroke bike on the track. I had it put up against the Yamaha YZ250F and the torque did the trick from down low while the power proved effective in the mid-range and top-end, leaving the 250 behind and eating two-stroke smoke.
The Keihin PWK 39 carburetor and the TVC power valve aren’t waist as they have much to do with the constant power and the feel when the throttle is wide open. Also, what contributes at the continuity of the ride and at the fact that the rider can pick the needed gear whatever is the riding type that it prefers, is the six-speed transmission. Smooth, reliable and easy to use, the gearbox is the 143.6cc engine’s best friend as the power developed by this last unit reaches the rear wheel and gets put to the ground in the most efficient way possible.
Maneuverability is also the key to this bike’s success as it can be easily directed everywhere on the track with great accuracy. You will notice that although it weights just a little more than 200 lbs it is very easy to handle and extremely responsive. Finding the best line around the track is just a think of visualizing it, not trying to make the bike go where you will like it to.
What also keep the SX competitive and reassuring are the WP suspensions offering 11.8 inches of travel through a 38mm front fork and 13.2 inches of travel from a compression and rebound adjustable monoshock. The fork, which is taken right off the 125 SX, offers strong bottoming resistance so it will inspire confidence even when the landing ahead looks tricky. The rear suspension will need a bit of getting used to as the right trace on the track won’t be hit from the first time, but afterwards, it will all be a kid’s play.
Brakes on this thing are top notch! I wouldn’t expect at anything else from a pair of Brembo discs, 260mm and 220mm, which proved effective on the smaller version, the 125 SX, also. Together with the griping motocross tires, you will have no problem getting this little two-stroke monster to a complete stop. Also effective before tight curves, these units will become your best friend on the 2008 KTM 144 SX. Good luck!
Well worth the MSRP of $5,798, this SX is a true demonstration of power coming from the Austrian manufacturer and going straight towards the AMA amateur MX Lites race class and planning on occupying the first place every time you’ll get it racing. It won’t disappoint you if that’s what you’re afraid off and it makes the bucks well worth.
Fine tuning the products is KTM’s base rule, but it seems that with this model they had everything sorted out from the start as it was based on 125 SX’s experience and nothing could go wrong. Everything that KTM had to do was to take an already impressive product in its lineup and have it radically upgraded and called some other way due to its displacement increase.
Engine and Transmission
Engine type: Single cylinder, 2-stroke
Displacement: 143.6 cc
Bore x stroke: 56 x 58,5 mm (2.20 x 2.30")
Transmission: 6 Gears
Carburetor: Keihin PWK 39
Control: TVC Power Valve
Lubrication: Mixture oil lubrication 1:40
Transmission lubrication: 15W50
Primary drive: 23:73
Final drive: 14:50
Cooling: Liquid cooled
Clutch: Wet multi-disc clutch, operated hydraulically
Ignition: Kokusan digital Magnet CDI
Chassis and Dimensions
Frame: Cental double-cradle-type 25 CrMo4
Subframe: Aluminium 7020
Handlebar: Renthal Aluminium Ø 28/22 mm (1.10 / 0.87")
Front suspension: WP USD Ø 48 mm (1.89")
Rear suspension: WP Monoshock PDS
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"; 100/90-19"
Chain: 5/8 x 1/4"
Main silencer: Aluminium
Steering head angle: 63°
Wheel base: 1471±10 mm (57.91"±0.39")
Ground clearance (unloaded): 390 mm (15.35")
Seat height: 925 mm (36.42")
Fuel capacity: approx. 7,5 Liter (1.98 gal)
Weight (no fuel): approx. 90,8 kg (200.2 lbs)