01. Engine & Exhaust
The 2022 KTM 250 SX-F FACTORY EDITION is powered by a 14,000 rpm powerhouse, that weighs a mere 57.5 lb (26.11 kg). The engine has been rotated 2 degrees backward, resulting in a 3 mm lower front sprocket position, along with a reduced engine height of 8 mm for improved mass centralization, lower weight, and improved anti-squat behavior. All major components and shaft arrangements have been carefully engineered to best suit the performance and handling characteristics of the overall package, once again making this the 250 four-stroke to beat.
Featuring a completely redesigned DOHC cylinder head, the 2022 KTM 250 SX-F FACTORY EDITION is a true 14,000 rpm performance monger. With the cylinder head featuring DLC coated finger followers, titanium valves - 32.5 mm intake, 27.5 mm exhaust - and an all-new, lightweight valve cover with fewer screws for easier service, this is a new benchmark in the 250 cc class.
Cylinder and piston
At the heart of the KTM 250 SX-F FACTORY EDITION is an all-new 81 mm bore and 48.5 stroke cylinder housing a forged bridged-box-type piston made by CP. Both the cylinder and piston are engineered from high-strength aluminum resulting in outstanding performance and reliability, while an increase in compression to 14.5:1, adds more torque and mid range power to the mix.
The KTM 250 SX-F FACTORY EDITION has a rigid crankshaft and a connecting rod that features a plain big (bottom) end bearing with two force-fitted bearing shells running directly on the crank pin. This design was essential for the extremely high engine speeds and unrivaled maximum power of the 250 cc 4-stroke engine. The design also enhances the engine's durability, allowing for longer crankshaft service intervals, which is a huge benefit in terms of time, effort and cost.
Crankcases and engine covers
All-new engine cover designs feature a textured surface for greater wear resistance and a slick new look thanks to its black finish. A high-pressure die-cast production process keeps the overall weight to a minimum, but optimizes mass-centralization and increases efficiency. A new steel oil pump gear and repositioned oil jets increase the overall oil pressure, resulting in improved overheating resistance and durability.
This new 5-speed transmission by Pankl Racing Systems is designed to be extremely light and durable while featuring a 250cc specific ratio of 24:72. A redesigned shift shaft and shift forks with a low-friction coating make for smoother, slicker shifting. But for really fast up-clicks, a new Quickshifter sensor allows clutchless upshifts and can be toggled on or off via the new QS handlebar switch. A new gear shift lever design also prevents dirt build-up and keeps the lever tip in its original position even in the toughest conditions.
Engine management system
A state-of-the-art KEIHIN engine management system, with electronic fuel injection and 44 mm throttle body, ensures fuel is used as efficiently as possible with maximum power as a result. The injector position guarantees optimal atomization of the fuel and air on the way to the combustion chamber, resulting in instant throttle response and thanks to the repositioning of the air filter box, more mid-range grunt too.
To balance the mass forces the KTM 250 SX-F's engine produces, it's fitted with a multifunctional balancer shaft, which effectively reduces vibration, while driving the water pump and timing chain. Now that's multitasking.
The 2022 KTM 250 SX-F FACTORY EDITION features an updated DS clutch, a single diaphragm steel pressure plate instead of traditional coil springs. The clutch basket is CNC milled from a single block of steel that allows the use of thinner steel liners and is a major contribution to the compact engine design. The benefits? Better traction and durability, improved clutch cooling, reducing clutch fade and heaps of gains in the trophy department.
The standard electric starter on the KTM 250 SX-F FACTORY EDITION uses a proven starter drive and a strong starter motor made by Mitsuba. As demonstrated time and time again, it provides quick and reliable starting, saving you precious time and energy when you need it most. A new, combined start/stop switch on the right side of the handlebar allows for easy and intuitive firing up.
Just like a championship contender, a high-performance race weapon also needs to stay cool under pressure. Thankfully, a set of radiators ideally positioned for a lower center of gravity, ensure this machine keeps it's cool. By using computational fluid dynamics technology together with a clever cooling circuit routing, the innovative system ensures the optimum engine temperature for the highest performance, no matter what the conditions.
When it comes to power delivery and performance, the exhausts on all KTM SX-F FACTORY EDITION models feature a model-specific header with an advanced Flow Design resonance chamber and a short, compact aluminum silencer that stays well within noise regulations. The header joining position and new, standardized mounting points and screw lengths across the 4-stroke exhaust systems design also allows the exhaust to be disassembled without removing the shock absorber, saving time in the pit lane, and gaining it out on the track. In this case, we'll let the sound do the talking.