KTM introduced their 250 EXC TPI and 300 EXC TPI off-road competition motorcycles as part of the brand’s 2018 model year lineup. The Austrian brand's revolutionary Transfer Port Injection (TPI) is the world’s first serial production fuel injection system for 2-stroke motors. The game-changing development is seen as part of Europe’s ongoing increase in environmental regulations; TPI has successfully made the 250 and 300 EXC enduros Euro 4 compliant. The 250 EXC TPI is expected to make its official race debut at the Erzbergrodeo 2017 to be held on June 15-18.
KTM insists that TPI technology drastically improves fuel efficiency, further cleans up exhaust emissions, and eliminates the demand for re-jetting. The advanced electronics avoid having to constantly make manual readjustments, in spite of any changes in altitude or weather conditions on race days. The need for pre-mixed solutions of fuel and oil is negated as well, since TPI’s automatic engine lubrication is managed from a separate oil tank via an electronically controlled oil pump. Throttle position and engine speed are read by sensors to determine and administer precise amounts of oil at any given time. KTM claims that this new oil injection method reduces exhaust smoke by up to 50%.
The TPI bikes utilize electric starters with ultralight lithium-ion batteries, while a cold start device opens a bypass for a supply of extra air. They feature the most modern engine management systems (EMS) for 2-stroke bikes to date. Constant monitoring of sensor data afford optimal injection of appropriate fuel amounts and ignition timing. Compensation for environmental factors (such as elevation and temperature) is automatic, and idle speed can be set on the TPI engines with an adjustment screw.
The KTM 250 EXC TPI is powered by a 249cc 2-stroke thumper nestled within its chrome-moly steel frame, while the square 300 EXC TPI (72 x 72 mm bore and stroke) bumps up displacement to 293.2 cc. Both use enduro-specific 6-speed transmissions with advanced No Dirt gear shift levers to prevent mud blockage. They each get a 260mm wave brake disc in front and a 220mm one in the rear, care of Brembo. Suspension is taken care of by WP Xplor 48mm inverted front forks with 300 mm of travel, along with a WP Xplor rear mono shock with 310 mm of travel solidly mounted to KTM’s Progressive Damping System (PDS) swingarm. Each motorcycle’s fuel capacity is measured at 9.25L, dry weight at a light 103 kg, and seat height at 960 mm.
In KTM tradition, both the 250 and 300 EXC TPI will come in special-edition Six Days versions donning special graphics for 2018 — offering top-of-the-line performance upgrades to celebrate the brand’s success at the FIM calendar’s oldest off-road race, the International Six Days Enduro (ISDE). The next ISDE is scheduled for August 28 to September 2 in Brive-la-Gaillarde, France. Some exclusive parts for the 250 and 300 EXC TPI Six Days are carbon pipe guards, adjustable suspension, map select switches, floating front brake discs, solid rear brake discs, a Supersprox Stealth 2-component rear sprockets, and engine guards. The Six Days editions include an additional front axle puller for easier front wheel removal. KTM’s iconic orange color carries over onto the Six Days’ frames, high-end CNC machined and anodized triple clamps, and chain guide.