More than just lightning fast
4-stroke rivals, beware: this tool might just be the sharpest in the shed. It’s hard to find a better power-to-weight ratio in the world of Enduro. If you want torque by the bucket loads, a top-end to die for and a lightweight chassis ready to rise to any occasion, give this 300cc lightning bolt a go.
The engine of the KTM 300 EXC has been known and respected for being the most powerful 2-stroke engine in its class. 2-strokes really do have a future at KTM. Their outstanding power-to-weight ratio, low cost and simplicity see to that. The KTM 300 EXC engine has been optimized for mass centralization, comes with a twin-valve controlled power valve, a balancer shaft for less engine vibrations, a 6-speed transmission and a hydraulically operated DDS clutch. This compact powerplant lays down the law in terms of 2-stroke power and torque and is the right choice for lovers of low purchase and maintenance costs. Oh, and of course don’t forget that 2-stroke symphony when you’re on the pipe.
This compact cylinder with a 72mm bore features a cutting-edge power valve unit with a sophisticated mechanism for the lateral support exhaust ports. Matched to a twin-component cylinder head, it is KTM’s secret to all-round grunt. The layout of the water jackets in the cylinder and head guarantees efficient heat dissipation when the going gets tough.
These die-cast crankcases allow the implementation of a balancer shaft. So your ride will be as relaxed as it is rapid. Plus, your new favorite engine will keep looking as fresh as the day you bought it: its engine covers feature a smart surface structure in order to reduce the wear caused by the rider’s boots.
A robust 6-speed transmission, its gear ratios perfectly in sync with the 300’s power band. An advanced ´No Dirt´ gear shift lever design prevents mud and sand from blocking the joint of the lever and guarantees trouble-free shifting.
Say goodbye to numb feet and hands. This engine design allows the implementation of a lateral balancer shaft in order to keep the vibrations to a minimum. You know what that means: more comfort, bigger smiles, less fatigue, more miles.
The KTM 300 EXC employs the KTM-developed DDS clutch (damped diaphragm steel) with a wear-free steel basket, extremely heat resistant clutch plates and new, nitrated steel liners. This clever design employs a diaphragm spring instead of the usual coil springs, making for considerably easier clutch action. A diaphragm spring also leaves sufficient space for a damping system to be integrated into the clutch hub. The goal is traction, but durability is as well. Light operation and telepathic amounts of control are standard with this hydraulic Brembo actuated clutch.
The KTM 300 EXC is fitted with a MIKUNI TX carburetor. This 38mm flat slide carb lives to provide smooth and controllable power all the way up to the rev limitation. With a new intake manifold the carburetor is turned 7° in order to reduce the overflow of fuel. And it’s less sensitive to different altitudes and temperatures, so you can pin it wherever, whenever. It gets a new setting too, improving power delivery and rideability.
The engineers meticulously tuned the pipe for maximum torque and power, so this little screamer is as tough as it is strong.
All 2-stroke models feature a new CDI control unit with an advanced hardware which improves the starting behavior of the engine. The ignition curves remain unchanged.
KTM engineers just love dropping weight year after year. The result: the 2018 KTM EXC models are the slimmest, lightest dirt bikes out there.
The high-tech, lightweight chrome-moly steel frame has a knack for easy handling, outlandish rideability, precise cornering and excellent stability. You can also count on high torsional rigidity and low longitudinal stiffness. This results in better absorption of the energy created from the front and rear suspension sucking up jumps and bumps. In short: more comfort and less rider fatigue. Laterally attached, lightweight engine head stays (the connection between cylinder head and frame) contribute to a reduced vibration level. Two threaded inserts in the lower cradle tubes allow for safe fixation of an optional skid plate. The engineers could pull off all that, while making their frame a big fat kilogram lighter than that of the lightest competitor on the market. In addition, it is easier to maintain, easier to work on and supplies more space for the tank and other components. The bike also features an extra-light subframe made of stable aluminum profiles, which tiptoes the scales at less than 900g.
Sophisticated ´No Dirt´ footpegs prevent smudging up the pegs, even when digging in deep ruts. The pegs on the Enduro models are 6mm higher than the ones used on SX models, which benefits ground clearance. But you can swap them at will.
Air filter box
The air filter box design offers maximum protection of the air filter against soiling, while ensuring maximum airflow. The large Twin Air filter is mounted in a stiff cage, which at the same time holds the system in place. This design is so simple, you could still pop a fresh one in with a face full of mud. Without tools. In seconds.
KTM engineers know how to handle handlebars. This tapered unit, made of high-strength aluminum by NEKEN, features a throttle assembly with a robust aluminum body and easy free-play adjustment. An ODI volcanized grip sits on the right, while on the left side of the bar a comfortable ODI lock-on grip requires no glue or wire to secure it.
The cast aluminum design offers low weight and a perfect flex behavior. The single-component casting process eliminates any inconsistencies and inherent weak points created by welding. It’s better looking too.
A lightweight polyethylene tank with a capacity of 9.5 liters. You will always be able to see how much fuel there’s left at a glance, thanks to the see-through plastic. By pushing the orange release button in the center of the fuel tank cap, the bayonet mechanism makes refueling quick and easy.
The EXC wheels feature lightweight, CNC machined hubs and high-end Giant rims guaranteeing maximum stability at minimum weight. The wheels are fitted with MAXXIS tires – perfect for surefooted performance off-road and stability on-road.
KTM’s proven cooling system routes the coolant from the cylinder head through the frame triangle, directly to aluminum radiators made by WP. Thanks to flow optimized internal circulation and CFD-calculated ventilation, the system is superbly efficient. In addition, new radiator protections improve heat dissipation. Especially in the mud. They are also integrated into the front part of the shrouds to protect the radiators in a crash.
KTM R&D, KISKA Design and all our factory riders had their say in shaping the plastics with one goal: complete harmony between rider and bike. Perfect ergonomics and contact points provide maximum comfort in movement on the EXC. The I-beam structures of the front and rear fenders guarantee maximum stability and a low weight thanks to well thought-out construction and mounting. They also stay cleaner for longer.
A new, tailor-made kit and a Factory orange frame. Because in this sport, champs deserve to look the part regardless of the dirt.
The PDS is kind of a KTM trademark where the shock absorber is directly connected to the upper side of the swingarm. This setup boasts the best possible mounting geometry and provides amazingly progressive damping. The shock absorber is mounted close to the centerline, which means nearly symmetrical loads for the swingarm and frame and more space for the exhaust system. A second piston works together with a closed cup (instead of a needle) towards the end of the stroke and is supported by a progressive shock spring for exceptional bottoming resistance. Various machined and anodized components and a distinctive WP color trim make this a valuable, high-end product compared to the less refined shock absorbers of the competition.
The WP Xplor 48 upside-down fork is a split fork developed by WP in close collaboration with KTM. It is fitted with a spring on both sides but features separated functions for each fork leg: compression damping is fitted on the left side, while rebound is on the right. The forks can easily be adjusted for compression and rebound with the twist of a dial on the top of the forks. New outer fork tubes and a reworked setting make for more sensitivity, improved damping behavior and a reduced weight. In addition, a sealed hydro-stop guarantees excellent resistance to bottoming-out. Due to high-quality materials and a state-of-the-art production process, the new WP Xplor 48 fork – with approx. 300mm of travel – has outstanding response and damping characteristics. A comfortable preload adjuster can be retrofitted and allows for a simple spring preload setting in three steps without tools (standard, +3mm, +6mm).
Fitted with forged triple clamps with an offset of 22mm, ensuring a solid grip of the fork and precise handling. The handlebar is adjustable forwards and backwards over 4 positions, so the EXC will fit you like your favorite gloves.
These high-tech Brembo babies are combined with lightweight Wave brake discs. You couldn’t brake any harder, better, faster or stronger.
Battery & Wiring harness
A strong lithium ion battery breathes life into the engine and contributes to low vehicle weight. The lightweight battery and wiring harness are centralized in a compartment above the air filter box, allowing the mechanic to remove the subframe without getting in conflict with the electronics. A happy mechanic is a good mechanic.
1-cylinder, 2-stroke engine
Kick and electric starter
Secondary gear ratio
Wet, DDS multi-disc clutch, Brembo hydraulics
Chrome-molybdenum steel central-tube frame
WP Xplor PDS shock absorber
Suspension travel (front)
Suspension travel (rear)
Front brake disc diameter
Rear brake disc diameter
Steering head angle
1482 ± 10 mm
Tank capacity (approx.)
Weight READY TO RACE (without fuel)
The illustrated vehicles may vary in selected details from the production models and some illustrations feature optional equipment available at additional cost.
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