Engine & Exhaust

Exhaust

When it comes to power delivery and performance, the exhaust plays a key role and packs a punch that is hard to beat. The 250 cc and 300 cc models feature HD exhaust pipes (heavy-duty) made by using an innovative 3D stamping process which produces a ribbed surface finish. This makes the pipe much stronger, with better resistance against rocks, while also helping to reduce noise drastically. The silencer features a compact shape and end cap with internal designs individually developed for each model, while it is mounted using an aluminum mounting bracket. In addition, the exhaust’s shape provides slim ergonomics and more ground clearance, while a perforated inner silencer tube works with lighter damping material for efficient and durable noise reduction.

Engine

A legend in its own right, the KTM 300 cc 2-stroke engine has long been a favorite when it comes to enduro weaponry. This is largely down to its exceptional power, low-down torque and overall lightweight. Thanks to state-of-the-art engineering, innovative 2-stroke design, and revolutionary TPI fuel injection technology, this powerplant has become a truly refined unit.

Cylinder

The KTM 300 XC TPI cylinder has a bore of 72mm and is fitted with a state-of-the-art power valve, which provides really smooth and controllable power characteristics. For the EFI application the cylinder features two lateral domes that hold the fuel injectors supplying fuel into the rear transfer ports. The downstream injection guarantees excellent atomization of the fuel with the upstreaming air. Thus the loss of unburnt fuel is minimal for fewer emissions, a more efficient combustion and reduced fuel consumption. A little tube in the back of the cylinder is connected with an intake pressure sensor, which supplies pressure data to the control unit.

Crankcases and engine covers

The compact engine cases are manufactured using a high pressure die-cast production process which 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 ride-ability. The engine covers feature a smart surface structure which reduces wear caused by the rider’s boots, keeping them looking as fresh as the day you bought your XC TPI.

Transmission

A robust 6-speed semi-close transmission features gear ratios perfectly in sync with the 300’s power band. An advanced ´No Dirt´ gear shift lever design prevents mud and sand from jamming the joint of the lever and guarantees trouble-free shifting.

Balancer shaft

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, less fatigue, more racing.

Clutch

The KTM 300 XC TPI employs the KTM-developed DDS clutch (damped diaphragm steel) with a robust steel basket, extremely heat resistant clutch plates and new, nitrated steel liners reducing the wear. 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.

Throttle body

The TPI engine is fitted with a 39 mm throttle body made by Dell`Orto. The airflow is regulated by a butterfly connected with a twin-cable throttle cam, which is operated by the handlebar throttle assembly. A throttle position sensor provides airflow data to the control unit, while a bypass screw allows the regulation of the idle speed. The cold start device also opens a bypass supplying more air. Via an oil intake tube oil supplied from the oil pump is mixed with the incoming air to lubricate crankshaft bearings and cylinder/piston etc.

Engine management system

The engine management system (EMS) of the TPI models features a control unit located below the seat. The ECU defines the ignition timing while the amount of fuel to inject is based on several sensor readings such as intake air pressure, throttle position and water temperature plus a new additional ambient air pressure sensor. Thanks to altitude and temperature compensation the rider does not need to worry about fiddling around with the jetting anymore. Should the rider decide to mount a radiator fan from the KTM PowerParts program, it will be controlled directly by the EMS without needing to add an additional thermal switch.

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.

Chassis

Airbox

The air filter box design offers maximum protection of the air filter against soiling, while ensuring maximum airflow, and together with the intake snorkels, results in optimal power and throttle response. The large Twin Air air filter is mounted on 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.

Frame

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 precisely calculated stiffness of the frame. 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 aluminum engine head stays (the connection between cylinder head and frame) contribute to more precise cornering and a reduced vibration level. The engineers were able to pull off all that, while making their frame 2.2 pounds 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 aluminum, which tips the scales at less than 2 pounds.

Swingarm

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.

Wheels

The XC-W wheels feature lightweight, CNC machined hubs and high-end Giant rims guaranteeing maximum stability at minimum weight. The wheels are fitted with Dunlop AT 81 tires – perfect for surefooted performance offroad.

Front suspension

The lightweight WP XACT front fork with AER technology, a 48 mm USD air-sprung fork developed by WP in close collaboration with KTM, is a split fork with separate functions for each leg. That means damping functions are on the right side, whereas the air spring is in the left. This left leg features a 2-chamber system with a capsuled air cartridge to prevent loss of air pressure. Should the outer seal start to leak, the internal cartridge pressure will keep the bike in position. The air spring is easy to adjust to any rider weight via a single air valve. No extra special tools are required; the fork air pump is supplied with the bike. The right fork leg integrates a damping cartridge that tailors to all your damping needs. It can be adjusted to the track conditions and the rider’s preferences with a twist of a dial (compression from the top, rebound from the bottom, 30 clicks each). Right off the dealer floor, this fork (with reworked damping characteristics and new piston) is more comfortable and more sensitive than ever. But you can still hammer the hell out of it.