01. Engine & Exhaust

Engine
The KTM 250 XC-F engine is known to be the strongest engine in the 250 cc class. It screams at the top of its lungs at 14,000 RPM, but is equally happy producing tons of torque and power across the rest of the rev range. Its compact architecture contributes to an excellent mass centralization, supporting the rideability of the bike. And it only weighs 47.6 pounds. That's including the incredibly beneficial E-starter.


Cylinder head
The centerpiece of the compact DOHC (double overhead camshaft) engine is the cutting-edge cylinder head. It features two overhead camshafts, which activate the titanium valves via super-light cam followers with a hard DLC coating.


Crankshaft
The KTM 250 XC-F's crankshaft utilizes a short connecting rod, which makes for an overall compact and lightweight engine with a snappy power delivery. A plain big (bottom) end bearing with two force-fitted bearing shells runs directly on the crank pin. The necessary oil feed for this bearing is ensured by the engine's pressurized lubrication. This design is a decisive benefit in terms of the crankshaft service interval, which can be lengthened due to the plain bearing. So just pin it, all day long.


Crankcases and engine covers
The design of the die-cast crankcases allows for minimal weight and a very centralized shaft configuration. This makes the engine short and compact, while contributing to an efficient centralization of masses. The engine covers also feature a solid surface structure, which reduces the wear caused by the rider's boots. This way, your XC-F will keep looking better longer.


Transmission
The engine is fitted with a smooth 6-speed semi-close PANKL transmission made of new and stronger materials. An advanced ´No Dirt´ gear shift lever design prevents mud and sand from blocking the joint of the lever and guarantees trouble-free shifting. All 4-stroke engines are fitted with a gear position sensor, giving the option of different engine characteristics for each gear. The transmission shaft features a C4 bearing that has a bigger overlap and guarantees better reliability even at extremely tough operating conditions.


Engine management system
The state-of-the-art Keihin engine management system with electronic fuel injection features a 44 mm throttle body. Thanks to its unique injector position, the engine's response is instantaneous. And to make life even easier, separate systems for cold starts and idle adjustment await you. The lightweight control unit features a unique traction and launch control system for lightning-quick response when the gate drops.


Cylinder and piston
Inside the short cylinder, with a bore of 78 mm, thumps a box-type piston made by CP. Its crown geometry is adapted perfectly to the high-compression combustion chamber, where its rigid structure and low weight shine. Thanks to the low oscillating masses, the engine is as snappy as it is strong.


Balancer shaft
The side-mounted balancer shaft does double duty also driving the water pump. Thanks to its perfect balance and low oscillating masses, engine vibration is kept to a minimum.


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 hydraulic Brembo system.


E-Starter
The KTM 250 XC-F is fitted with a unique E-starter as standard, which is a clear advantage when it comes to crunch time in the heat of battle. A strong starter motor made by Mitsuba will fire time and time again at the push of a button. Even under extreme conditions, thanks to its more heat resistant O-ring.


Cooling
KTM's proven cooling system routes the coolant from the cylinder head through the frame triangle, directly to aluminum radiators. Thanks to flow optimized internal circulation and CFD-calculated ventilation, the system is superbly efficient. In addition, radiator protections improve heat dissipation. Especially in the mud. They are also integrated into the front part of the shrouds to protect the radiators from impact.


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.
