01. Engine & Exhaust
Combining compact dimensions with immense power output, this 449.9 cc fuel-injected SOHC powerplant is the most powerful and refined on the market. Its class-leading power delivery is available throughout the entire rev range and with its low weight of only 29.2 kilograms, it's also one of the lightest 450 cc mills out there.
The KTM 450 EXC-F engine is fitted with a compact SOHC cylinder head for optimal mass centralization. The head configuration promises efficient power delivery and unrivaled performance. A single overhead camshaft also ensures optimal gas flow, with low-friction rocker arms and timing chain guides guarantee consistent performance throughout the rpm range.
Located in an ideal position close to the center of gravity, The KTM 450 EXC-F crankshaft contributes to easier handling. It utilizes a short connecting rod, which makes for an overall compact and lightweight engine. The engine's pressurized lubrication system provides the necessary oil feed for the big end bearing. This design has a direct benefit for the crankshaft with extended service intervals. So just pin it, all day long.
Crankcases and engine covers
A lightweight engine case design allows for a very centralized shaft configuration while contributing to an efficient centralization of mass. Additionally, the engine covers feature a smart surface structure that reduces the wear caused by the rider's boots, keeping them looking as fresh as the day it rolled off the production line, while a reinforced clutch cover and engine guard mean the engine case is more robust.
The KTM 450 EXC-F features 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. All four-stroke engines are fitted with a gear sensor, giving the option of different engine characteristics for each gear.
Engine management system
The state-of-the-art Keihin Engine Management System, with electronic fuel injection, features a 42 mm throttle body with separate systems for cold starting and idle adjustment. The throttle cable mount also allows for easy access and a smooth routing of cables for crisp throttle response, every time.
Cylinder and piston
Inside the short 95 mm bore cylinder is an extremely lightweight, box-in-box type piston made by König. In conjunction with the light but extremely durable piston pin, it is a major contributor to the engine's high performance, low vibrations, and speed. The compression ratio of 12.75:1 delivers exceptional engine performance and reduces the risk of engine knocking. Additionally, the top of the piston is optimized for highly efficient fuel combustion.
The multifunctional side-mounted counter balance shaft masterfully balances all the oscillating forces, while also driving the water pump. It effectively keeps engine vibrations to a minimum, resulting in the smoothest ride even at the highest engine speeds.
The KTM 450 EXC-F is fitted with the extremely durable, KTM-developed DDS clutch (damped diaphragm steel), with a wear-free steel basket and heat-resistant clutch plates. It uses a diaphragm spring instead of the usual coil springs, which results in considerably easier clutch action. Additionally, the Brembo hydraulic system provides easy and precise clutch modulation throughout the entire operating temperature range.
The standard electric starter on the KTM 450 EXC-F uses a proven starter drive and a strong starter motor made by Mitsuba. As demonstrated time and time again, it provides quick and reliable starting, saving you precious time and energy when you need it most.
Keeping the engine cool when the going gets tough comes courtesy of a pair of radiators, mounted close to the center of gravity. These make use of CFD technology (Computational Fluid Dynamics) and clever coolant circuit routing, achieving optimum engine temperature for the highest performance, in all conditions. Above all, the delta distributor, integrated into the frame triangle, features a large center tube for highly efficient coolant flow, as well as radiator fans as standard on all 4-stroke models.
Packing a punch and delivering an unmistakable engine note, all 4-stroke KTM EXC models feature an easy-access two-piece header pipe that can be disassembled easily to allow access to the rear shock. An aluminum muffler sleeve has a short and compact profile.