01. Engine & Exhaust

Engine
Thanks to state-of-the-art engineering, innovative 2-stroke design and revolutionary TPI fuel injection technology, the 150 cc 2-stroke powerplant is more refined than ever before, delivering class-leading power throughout the entire rev range. The benefit to this compact, lightweight 2-stroke, is reflected in the highly effective power delivery and easy rideability, making it a great option for those looking to delve into more extreme action.


Cylinder
The KTM 150 EXC TPI cylinder has a bore of 58mm and with the aid of a sophisticated power valve, provides really smooth and controllable power characteristics. For the EFI application the cylinder features two lateral domes which hold the fuel injectors that supply fuel to 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, resulting in less emissions, a more efficient combustion and reduced fuel consumption. A small tube in the back of the cylinder is connected with an intake pressure sensor, which supplies pressure data to the control unit. The cylinder features a power valve unit with a sophisticated mechanism for the lateral support exhaust ports. The exhaust port layout increases engine performance, while the upper contour of the exhaust port has been machined to ensure more accurate port timing. The cylinder, with TPI technology, produces outstanding performance over the entire rev range with impressive torque.


Crankcases and engine covers
Lightweight, die-cast crankcases featuring a high crankshaft and clutch shaft position, located close to the center of gravity, which results in optimal mass centralization and outstanding rideability. In addition, the engine body is extremely lightweight and compact, while still able to house an E-starter. And because looks matter, the engine covers feature an advanced surface structure in order to reduce the wear caused by the rider´s boots.


Transmission
The KTM 150 XC-W TPI is fitted with a robust 6-speed transmission made by PANKL Racing Systems. The gears are made of a strong, forged raw material, ensuring the highest durability and reliability level. The gear ratios are perfectly in sync with the 150's power band. The latest production technologies allowed for compact dimensions and minimal weight. Keeping safety in mind, an advanced ´No Dirt´ gear shift lever design prevents muck from blocking the joint. Because even dirt lovers hate mud when it's in the wrong places.


Clutch
The 150 EXC TPI is fitted with a DS (diaphragm steel) clutch. It features a one-piece clutch basket and primary gear made of high-strength billet steel. Its compact rivet-less design guarantees unbeatable reliability. The clutch is fitted with extremely heat-resistant steel carrier friction discs which ensure excellent disengagement of the clutch and are pre-tensioned by means of a diaphragm spring, substantially reducing the lever force required by the Brembo hydraulic system.


E-Starter
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.


Engine management system
The engine management system (EMS) of the TPI models features a control unit located below the seat. The control unit determines the ignition timing and the amount of fuel to inject is based on several sensor readings such as intake and ambient air pressure, throttle position, oil and water temperature. Thanks to altitude and temperature compensation the hassle and time of jetting a 2-stroke is no more.


Oil pump
Pre-mixing 2-stroke fuel is a thing of the past for KTM XC-W TPI owners. The 2-stroke range is fitted with an oil tank featuring flexible mountings, which greatly improve durability and reliability. In addition, a mesh filter helps prevent dirt getting into the oil pump. Mounted below the oil tank, the oil pump delivers the lubricant directly to the throttle body, where it is mixed with the incoming air to lubricate the piston and crankshaft. Using engine speed and throttle position sensor data, the engine management's precise electronic control of the oil pump ensures that the ideal amount of oil for any given conditions is used. The filler cap assembly for the oil tank is located between the fuel tank and steering head, utilizing a hose in the upper frame tube to transfer the oil to the storage container. With an average fuel-to-oil ratio of 1:80, the oil capacity of about 0.7 liters is sufficient for at least five tanks of fuel.


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.

TPI Alternator
To accommodate the power requirements of the upgraded engine management system, the TPI models are now with a powerful 196 W alternator and a voltage regulator. The same as can be found on the EXC-F 4-stroke models.

Cooling
Maintaining the optimal engine temperature is crucial to ensuring consistent horsepower throughout the ride. The KTM 300 XC-W TPI features radiators which are mounted close to the center of gravity and match the design of the shrouds perfectly, in order to achieve perfect ergonomics. The additional KTM PowerParts radiator fan is regulated by the EMS control unit for easy installation. Thanks to flow optimized internal circulation and CFD-calculated ventilation, the system is superbly efficient. In addition the radiator protectors 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.


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 pipe is produced with the latest 3-D stamping technology and has an optimized shape. It works perfectly with the TPI engine, producing excellent enduro-specific performance with impressive bottom end power. 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, a perforated inner silencer tube works with lighter damping material for efficient and durable noise reduction.
