MOrons keep asking, when will we see the return of the modern two-stroke? It might be looking right at us in KTM’s new 250 XC-W TPI. Granted, the new XC-W (Xross-Country, Wide-ratio trans) remains a decidedly off-road only motorcycle (depending really on where you live). But its all-new Transfer Port Injection system marks the most radical departure back toward clean-burn two-stroke motorcycle tech since Honda’s Radical Combustion tech failed to launch 20 years ago.


KTM’s release says:

KTM’s 250cc engine is known to be the most powerful and most competitive 2-stroke engine in the world. And now things get even better. The 2018 KTM 250 XC-W TPI boasts a newly developed and patented TPI (transfer port injection) fuel injection system – a truly unique feature when it comes to 2-stroke race bikes. The patented EFI system with two injectors into the transfer ports of the cylinder makes the engine much smoother to ride and reduces the fuel consumption drastically, a global game changer in terms of technology. Gone is the hassle of jetting, premixing gas and difficult starting. It was time to give a new push to 2-stroke technology and prove 2-strokes have a bright future. The KTM 250 XC-W TPI is leading the charge as the most advanced READY TO RACE 2-stroke.

All that’s being sucked in by the 39mm Dell’Orto throttle body is pure air. Only after the piston has ascended past its exhaust ports is fuel introduced into the cylinder via a pair of injectors in the transfer ports. That should result in, as the PR says, greatly reduced fuel and oil consumption. It could also possibly result in a motorcycle that will qualify for a California Green Sticker – kind of a big deal for KTM sales, which allows the bearer to ride year round in the Golden State instead of only in the wintertime.


The bike’s new engine management system controls ignition timing and fuel delivery based on information from five sensors reading intake and ambient air pressure, throttle position, and oil and water temperature. An electronic oil pump feeds oil from a 700cc oil tank into the intake to mix with fuel for an optimum mix under any conditions, while reducing smoking by 50%; that 700cc (about two Bud Lights) should be enough for up to five tanks of fuel.

KTM says the new XC-W with TPI weighs in at 227 pounds without fuel; meanwhile the Mikuni carburetor-equipped version weighs 220. There’s also a 300 XC-W, but that one’s not coming to America. The 250 TPI, KTM says, won’t be here till late Fall, and only then in very limited numbers. Price indeterminate at this time.