INSIDE KTM’S 2018 FUEL-INJECTED
250XC-W TPI TWO-STROKE ENGINE
Because of the Euro- 4 pollution regulations in Europe, KTM
is finally ready to release the fuel-injected two-stroke they have
been working on for the last decade. The most significant
thing about KTM’s design is that it uses transfer port injection
(TPI) fed by injectors on each side of the cylinder. Unlike four-
stroke fuel injection where the fuel is injected into the combus-
tion chamber via the intake ports, KTM’s two-stroke version
feeds fuel directly between the bottom end and combustion
chamber through the transfer ports. The fuel-injected 250cc
two-stroke engine will only come on the 2018 KTM 250XC-W
TPI offroad model. When we get one from Austria, we will tell
you what it’s like to ride it.
(Left) KTM’s TPI fuel-injection
system means no rejetting for
altitude or premixing of fuel.
Additionally, fuel consumption
will be reduced, as will emissions.
(Right) Replacing the 38mm
Mikuni TMX carb is a 39mm,
throttle body. The throttle body
has nothing to do with the fuel
supply, it only controls air flow.
The only fuel-injected KTM for 2018 will be the
250XC-W TPI. You don’t have to run pre-mix in
the fuel-injected two-stroke. Oil injection is controlled by a pump that feeds oil from the 700cc
tank. The oil tank is located in the frame. The oil
cap is in front of the gas cap.