Motorcycle specifications KTM250 EXC TPI 2020 Reaching new heights

engine and silencer

kTM's wide range of 2-stroke off-road competition bikes is a true technological showcase for the brand. Two years after the introduction of the world's first 2-stroke off-road motorcycles to feature electronic fuel injection, KTM is once again causing a stir with its next-generation a new generation of off-road competition engines, featuring a revolutionary TPI system. This proves just how much KTM believes in the future of 2-stroke technology. The advantages are obvious: in addition to the significant reduction in fuel consumption and pollutant emissions, this system eliminates the need for fuel premixing and manual intervention by the rider to fine-tune the bike's carburation. As a result, the engine can deliver its full potential, whatever the circumstances.

cylinder

the cylinder of the 250 EXC TPI, with its 72 mm bore, features a sophisticated exhaust valve control system to ensure smooth power delivery. Injectors are positioned on either side of the cylinder to feed fuel to the rear transfers. Downward injection offers the advantage of excellent atomization with rising air. Combustion is therefore more efficient, resulting in fuel savings and lower emissions. A small tube at the rear of the cylinder is connected to the intake pressure sensor, which communicates the air flow to the control unit. The 2020 version features state-of-the-art exhaust valve control and a sophisticated mechanism for the side exhaust outlets. The new tailpipe configuration contributes to enhanced engine performance. The upper contour of these components has even been machined to ensure ultra-precise timing. Last but not least, the new models allow the use of a more common type of conventional spark plug.

crankcases and covers

the use of high-pressure die-casting has resulted in a relatively compact crankcase that is even lighter, while maintaining its strength and durability. The crankcase design has enabled KTM engineers to move the shaft mounts closer to the center of gravity, so as to better centralize the masses and enhance rideability. Another interesting innovation to keep your EXC's engine as radiant as in the early days: crankcase covers with an elaborate surface structure designed to reduce wear caused by the rider's boots.

gearbox

the 250 EXC TPI is now equipped with a new, more robust 6-speed gearbox, manufactured by PANKL RACING SYSTEMS. The transmission ratios of the previous version have been retained. The new gearbox is made from a stronger forged material, ensuring superior durability and reliability. Another highlight of the 250 EXC TPI's gearbox is the "zero dirt" design of the selector. Designed on the same principle as the footrest, it prevents the accumulation of dust and enables the gearbox to remain operational in all conditions.

engine management

the engine management system (EMS) on TPI models features a control unit located under the seat. Ignition timing is calculated by the ECU. The precise amount of fuel to be injected depends on sensor readings such as intake air pressure, throttle position and water temperature. Ambient air pressure is also taken into account. As the system is designed to compensate for altitude and temperature fluctuations, injection requires no manual intervention on the part of the pilot. Should the rider decide to fit a cooling fan (available in the KTM PowerParts catalog), it will be placed under the direct control of the engine management system (EMS) without the need for an additional thermocontact. An optional map selector can be purchased to change engine modes on the fly and adapt power delivery to conditions.

balancer shaft

numb hands or feet are not inevitable. The engine's design has made it possible to use a side-mounted balancer shaft that helps minimize vibrations. Driving is more comfortable and less tiring.

clutch

the 250 EXC TPI uses a DDS (Damped Diaphragm Steel) clutch developed by KTM. a wear-free steel clutch housing, heat-resistant clutch plates and nitrate-treated steel liners. This clever design is distinguished by the use of a diaphragm spring instead of the usual coil springs, giving the clutch greater flexibility. The diaphragm spring also leaves ample room for a damping system integrated into the clutch hub, to enhance traction without compromising durability. The clutch is activated by a hydraulic system manufactured by Brembo, which plays an essential role in the clutch's progressiveness and flexibility.

oil pump

owners of an EXC TPI can now do without the traditional 2-stroke oil/fuel pre-mix. The 2-stroke oil tank has been redesigned for 2020 models. The mounting system is more flexible than before, for even greater durability and reliability. A sieve has also been added to prevent impurities from entering the oil pump. The oil drawn by the oil pump (mounted beneath the oil reservoir) passes through the injection body, where it is mixed with incoming air to lubricate the piston and crankshaft. Based on engine speed and data from the throttle valve position sensor, the Engine Management System (EMS) central electronic control unit (ECU) determines the ideal quantity of oil to use, according to current conditions. The oil filler cap, located between the fuel tank and the steering column, feeds the oil tank via a hose in the upper part of the frame tube. With an average fuel-oil ratio of 1:80, the tank has enough capacity (0.7 liters) for at least five fill-ups.

injection unit

the TPI injection engine features a new 39mm throttle body developed by Dell`Orto. The amount of air entering the engine is regulated by a throttle linked to a cam (with two cables) controlled by the handlebar throttle. In addition, a throttle valve position sensor communicates air flow to the control unit. On 2020 models, idle speed can be fine-tuned using the bypass screw. The cold-start device opens a bypass circuit to supply the extra fuel required for cold starts. The oil supplied by the electronic oil pump passes through the intake pipe before being mixed with the incoming air to lubricate the engine's moving parts.

tPI alternator

to meet the power requirements of the new engine management system (EMS), TPI models are equipped with a TPI alternator.models are equipped with a voltage regulator and a generator capable of supplying 196 W (the same as on EXC-F 4-stroke models).

cooling

to ensure smooth power delivery, it's essential to maintain optimum engine temperature. To this end, the 250 EXC TPI is equipped with new radiators, 12 mm lower than its predecessor. This position, perfectly matched to the design of the new spoilers, lowers the center of gravity and enhances ergonomics. Thanks to CFD (Computational Fluid Dynamics) and a clever cooling circuit, this innovative system ensures that engine components are kept at the ideal temperature to guarantee the highest level of performance, whatever the conditions. To ensure more efficient circulation of coolant between the cylinder head and radiators, the diameter of the central tube of the exhaust pipe (integrated into the frame wishbone) has been increased by 4 mm, representing a 57% increase in flow cross-section. Special radiator guards not only protect the radiators from stones and other debris, but also distribute the force of impact around them.

muffler

the new exhaust system gives the engine a smoothness and liveliness that are hard to match. The 250 cm3 and 300 cm3 models feature new, ultra-robust exhaust manifolds (with an impeccable surface finish), obtained using an innovative 3D stamping process. These collectors have the advantage of being more resistant to stone impact and considerably reduce noise emissions. The silencer has a new shape and a new end cap. The internal structure has been specifically modified for each model. The muffler's plastic mounting system has been replaced by ultra-lightweight welded brackets. The new shape of the exhaust system has the advantage of being more ergonomic and increasing ground clearance. The use of a perforated inner tube and a lighter insulating material (rockwool) also contributes to improved muffler efficiency and noise attenuation. The overall weight saving is 200 grams.

chassis

to be truly competitive, a 2-stroke enduro bike needs to be light. So it's no surprise that the 250 EXC TPI is one of the lightest, slimmest and most agile enduro bikes in its class.

frame

all EXC models feature a new high-tech lightweight chromoly steel frame, made of hydroformed tubes assembled by automated welding. Engineers retained the competition-proven geometry, but reworked certain parts of the frame to optimize rigidity. The ultimate aim was to improve rider feedback, agility and stability. The lugs connecting the cylinder head to the frame are now made of aluminum. Mounted laterally, they help limit vibration levels and refine the bike's trajectory in corners. The new side frame protectors feature a structured surface for improved grip. They also protect the rider from the heat generated by the muffler on the right-hand side. The 250 EXC's engine has been lowered by 1° in relation to the swingarm axis, considerably improving front-wheel driveability. The rear loop is made of ultra-light, stable aluminum sections, longer (40 mm more) and lighter (900 g less) than before, designed to reinforce the stability of the rear shell.

swingarm

the 250 EXC TPI's new aluminum monoblock swingarm, produced by high-pressure die-casting, has been designed to offer rock-solid strength, while keeping weight to an absolute minimum. The monoblock casting process not only optimizes bending behavior and material weight, but also allows a wide range of geometries.

wheels

featuring ultra-light CNC-machined hubs and top-of-the-range GIANT rims, the wheels on all Enduro models guarantee maximum stability despite limited weight. The aluminum spoke nipples on 2020 models have been redesigned to reduce the frequency with which spokes need to be re-tensioned.

front suspension

all EXC models inherit the latest WP XPLOR USD fork with separate damping circuits (48 mm in diameter), designed by WP and KTM. Although both fork arms are equipped with springs, their functions differ. The left arm handles compression damping, while the right arm handles rebound. To fine-tune each of these settings, simply turn the 30-notch knob above each fork tube. Although this fork is already renowned for its sensitivity and efficiency, it features a perfectly calibrated floating piston for even more even damping on the 2020 model. New fork top caps and new, more intuitive adjustment knobs, with new colors and graphics, are also featured. The rider also benefits from new settings to raise the front axle for greater resistance to bottoming.

rear suspension

an essential component of the proven PDS rear suspension, the WP XPLOR shock absorber is connected directly to the swingarm, without the need for an additional linkage system. In addition to saving weight, this solution reduces the risk of snagging on large stones. To ensure optimum progressiveness of the enduro-specific damping, a second piston is combined with a cup-shaped end-stop and supported by a progressive-action spring. To increase resistance to bottoming without sacrificing comfort on the 2020 model, the second piston has been redesigned, and the sealing and shape of the end stop have been optimized. New XPLOR PDS shock absorber settings, specific to the new frame and front-end configuration, improve damping characteristics. Fully adjustable, including high-speed and low-speed compression, this shock absorber can be adapted to suit track conditions or rider preferences.

brakes

these Brembo brakes, little jewels of technology, are combined with Wave brake discs renowned for their lightness. Rarely has an off-road motorcycle offered such an efficient braking feel.

fuel tank

all EXC models feature a new, ultra-light, ergonomic polyethylene fuel tank. The quarter-turn bayonet cap eliminates time-consuming resealing of the tank. And since the tank is made of transparent plastic, you can see how much fuel is left at a glance. This model features an integrated fuel pump system and fuel level indicator. The 90-degree fuel line connection further protects the tank from damage.

air filter housing

the air filter housing of the 250 EXC TPI has been completely redesigned to optimize flow dynamics. Combined with the new intake snorkels, it ensures maximum power delivery and excellent acceleration. In addition to the obvious performance gains, the new design also protects the air filter from clogging. The rigid support for the large Twin-Air filter has been designed to minimize installation errors. As on previous models, the filter can be serviced in record time and without tools, a typically KTM feature.

ergonomics and comfort

kTM has drawn on its long experience and decades of racing success to perfect the ergonomics of the 250 EXC TPI and create the perfect osmosis between man and machine. This gives the rider total freedom of movement and optimum comfort, whatever the conditions. The rear light has also been redesigned to match the new shape of the rear hull and front cross plate holder.

handlebars

all EXC models feature the same ultra-strong, profiled aluminum handlebars made by NEKEN. These can be adjusted to four different positions. right: an ODI vulcanized handlebar grip available as standard; left: an ODI lock-on handlebar grip that's as comfortable as it is practical, thanks to its glue- and wire-free mounting system. All models can also be fitted with an optional handlebar-mounted map selector to switch between Standard and Advanced power curves.

saddle

the saddle on the EXC 2020 motorcycle range has a more ergonomic shape. It also benefits from even more comfortable foam padding. A long screw on the side secures the saddle to the motorcycle, making handling easier and safer.

styling and graphics

the fairing of the 250 EXC TPI marks a new stage in the evolution of motorcycles, the result of a joint effort by KTM factory riders, KTM R&D specialists and the design agency Kiska GmbH. The shape of the fairing on the bikes in the Enduro range allows the rider to feel at one with the machine. The main focus has been on contact points, to ensure total freedom of movement for the rider and enhanced handling. The special shape of the front and rear shells ensures maximum stability and minimum weight. The rear light has been redesigned to match the new shape of the rear shell and front cross-plate bracket. The new overmolded graphics confirm the bike's sporting intent and the ambitions of the KTM brand.

footrests

sophisticated "zero-dirt" footrests prevent the gear selector from getting dirty, even when riding in deep ruts. To improve ground clearance, the gear selector on Enduro models is 6 mm higher than on SX models. But you're free to change it if you like.

software and electronics

eXC TPI models feature one of the most advanced engine management systems ever designed for a 2-stroke enduro. Ignition timing is calculated by the control unit (ECU). The precise amount of fuel to be injected depends on sensor readings such as ambient and intake air pressure, throttle position and water temperature.

battery and wiring harness

all engines are equipped with the tried-and-tested electric starter, a major off-road asset. To start the engine every time, the starter is powered by an ultra-lightweight 2 Ah lithium-ion battery. The wiring harness has been optimized. Most of the electrical components are grouped under the seat, for easier access and greater reliability.

News and media credits: KTM