01. ENGINE & EXHAUST

TUNED FOR POWER
EXHAUST
When it comes to power delivery and performance, the exhaust on all 4-stroke models plays a key role and packs a punch that is hard to beat. It features a model-specific header pipe with an advanced resonator called FDH (Flow Design Header), which is a small chamber around the pipe. The design allows the exhaust to be disassembled without removing the shock absorber and also provides better access to the shock. The aluminum sleeve, end cap and internal design of the silencer allow for slimmer ergonomics, making the bike feel narrower, without compromise to regulatory noise limits.

UNRIVALLED POWER
ENGINE
The engine of the 2020 KTM 350 SX-F is neatly arranged in a compact and light (58.6 lbs) construction. It features an innovative clutch system; perfectly geared, durable transmission, and a lightweight DOHC (double overheard camshaft) cylinder head, which all contribute to making it an extremely impressive engine. It also features a new, stronger oil pump intermediate gear, for improved reliability. Fitted with the latest electronic fuel injection system and a useful electric starter, just one push of a button fires up this impressively competitive engine.

CYLINDER HEAD
The cylinder head on the KTM 350 SX-F is the gateway to its excellent power. It features two overhead camshafts with friction-optimized super-fine surfaces, connected to DLC coated finger followers that activate four lightweight titanium valves (intake 36.3 mm, exhaust 29.1 mm). KTM engineers have maximized the flow rate, delivering an optimal power band, with outstanding performance across the entire 13,400 rpm range.

CRANKSHAFT
The KTM 350 SX-F’s crankshaft features a stiff design and utilizes a short, lightweight connecting rod, contributing to the incredibly dynamic and efficient power delivery. The big end bearing features two force-fitted bearing shells, which run directly on the crank pin. This design is a prerequisite for the extremely high engine speed levels and the unrivalled power of the 350 cc. The design also enhances durability, allowing for long crankshaft service intervals, resulting in less effort and cost – and more time spent on two wheels.

CRANKCASES AND ENGINE COVERS
The compact engine cases are manufactured using a high pressure die-cast production process that helps with weight reduction, while retaining strength and durability. The design allows for optimal shaft arrangements close to the center of gravity, resulting in ideal mass centralization and easier rideability. The engine covers feature a smart surface structure that reduces wear caused by the rider’s boots, keeping them looking as fresh as the day you bought it.

TRANSMISSION
The KTM 350 SX-F is fitted with a robust 5-speed transmission. The gear ratios were carried over from its predecessor and are perfectly suited for the MX track. Another highlight of the transmission is the ‘no-dirt’ gear shifter. Similar to the footpeg design, it prevents the build-up of dirt and ensures the next gear is always available, no matter what the conditions.

ENGINE MANAGEMENT SYSTEM
The state-of-the-art KEIHIN Engine Management System, with electronic fuel injection, features a 44 mm throttle body. The injector position guarantees optimal atomization of the fuel and air on the way to the combustion chamber, resulting in instant response and maximum performance when opening the throttle. There are also separate systems for cold starting and idle adjustment. The ECU features maps which have been developed to precisely match the exhaust and cylinder head, with options for regulating traction and launch control. It also provides different maps for each gear, according to the information received from the gear sensor, ensuring maximum power as you shift through the gears.

CYLINDER AND PISTON
The 88 mm bore cylinder houses a lightweight, forged, bridged, box-type piston, made to the highest standards by CP. It has an extremely rigid structure and features a unique crown shape to suit the high-compression combustion chamber. The compression ratio is at 14:1 and thanks to the combination of low oscillating masses, the engine displays extremely lively characteristics.

BALANCER SHAFT
In order to balance the mass forces the KTM 350 SX-F produces, the engine is fitted with a multifunctional counter-balance shaft. It effectively reduces vibration, while driving the water pump and timing chain.

CLUTCH
The DS (diaphragm steel) clutch literally puts the control back in the hands of the rider. It features a durable, one-piece clutch basket and primary gear, made of high-strength billet steel, guaranteeing unbeatable reliability. It is fitted with extremely heat-resistant steel carrier friction discs, which are pre-tensioned by means of a diaphragm spring, ensuring the most effective disengagement of the clutch. This design substantially reduces the operating force required to pull the clutch and is made even easier with the BREMBO hydraulic system.

E-STARTER
The standard electric starter on the KTM 350 SX-F uses a proven starter drive and a strong starter motor made by Mitsuba. It provides quick and reliable starting, saving you precious time and energy when you need it most, always ensuring the strongest possible race finish.

HANDLEBAR MAP SELECT SWITCH
Within easy reach of the left grip on all four-stroke models, is a multifunctional handlebar map switch, which features the innovative control functions; traction control; launch control and alternative power curves (standard <-> advanced). The TRACTION CONTROL is a unique feature that guarantees more efficient traction and better control when accelerating the bike, especially in challenging track conditions. It can be activated on the handlebar map switch while riding. With a simple push of two buttons at idle speed, the rider can also activate LAUNCH CONTROL, ensuring the most effective launch out of the gate. The map switch also gives the rider the chance to select an alternative power map besides the standard configuration, providing him with options during the race.

MAINTAINING THE OPTIMAL ENGINE TEMPERATURE IS CRUCIAL TO ENSURING CONSISTENT HORSEPOWER THROUGHOUT THE RIDE. THE KTM 350 SX-F FEATURES RADIATORS WHICH ARE POSITIONED FOR A LOWER CENTER OF GRAVITY. THEIR DESIGN MATCHES THE SHROUDS PERFECTLY AND OFFERS A GREAT SLIM FEEL TO THE ERGONOMICS. BY USING CFD TECHNOLOGY (COMPUTATIONAL FLUID DYNAMICS) TOGETHER WITH A CLEVER COOLANT CIRCUIT ROUTING, THE INNOVATIVE SYSTEM ENSURES THE OPTIMUM ENGINE TEMPERATURE FOR THE HIGHEST PERFORMANCE, NO MATTER WHAT THE CONDITIONS. THE RADIATORS ALSO FEATURE SPECIAL PROTECTORS THAT SERVE NOT ONLY AS PROTECTION FROM FLYING ROCKS AND DEBRIS BUT ALSO AS A BRACE THAT DISPERSES ENERGY AROUND THE RADIATORS IN THE EVENT OF AN IMPACT.
COOLING
Maintaining the optimal engine temperature is crucial to ensuring consistent horsepower throughout the ride. The KTM 350 SX-F features radiators which are positioned for a lower center of gravity. Their design matches the shrouds perfectly and offers a great slim feel to the ergonomics. By using CFD technology (computational fluid dynamics) together with a clever coolant circuit routing, the innovative system ensures the optimum engine temperature for the highest performance, no matter what the conditions. The radiators also feature special protectors that serve not only as protection from flying rocks and debris but also as a brace that disperses energy around the radiators in the event of an impact.

TUNED FOR POWER
EXHAUST
When it comes to power delivery and performance, the exhaust on all 4-stroke models plays a key role and packs a punch that is hard to beat. It features a model-specific header pipe with an advanced resonator called FDH (Flow Design Header), which is a small chamber around the pipe. The design allows the exhaust to be disassembled without removing the shock absorber and also provides better access to the shock. The aluminum sleeve, end cap and internal design of the silencer allow for slimmer ergonomics, making the bike feel narrower, without compromise to regulatory noise limits.

UNRIVALLED POWER
ENGINE
The engine of the 2020 KTM 350 SX-F is neatly arranged in a compact and light (58.6 lbs) construction. It features an innovative clutch system; perfectly geared, durable transmission, and a lightweight DOHC (double overheard camshaft) cylinder head, which all contribute to making it an extremely impressive engine. It also features a new, stronger oil pump intermediate gear, for improved reliability. Fitted with the latest electronic fuel injection system and a useful electric starter, just one push of a button fires up this impressively competitive engine.