VOL. 54 ISSUE 22 JUNE 6, 2017 P125
TPI engine through five sensors. The
sensors include intake air pressure, oil
temperature, air pressure, throttle posi-
tion and water temperature. In order to
accommodate the power requirements
of the fuel injection system, like the
ECU, sensors, spark plug, diagnostics
and fuel pump, the TPI models are fitted
with a more powerful generator, rated at
196W. This is the same system that the
EXC-F four-stroke models use, and two-
stroke TPI models also use the EXC-F
voltage regulator.
The 2.4-gallon translucent polyeth-
ylene fuel tank makes it easy to gauge
the fuel level from the outside. The
fuel-pump system, like the four-stroke
design, is located in the gas tank. The
TPI bikes also feature a fuel level sensor
to let you know when you need more
gas. If you ride in hot weather or slow
and technical terrain, adding a cooling
fan is a simple plug-and-go install. The
new ECU controls the fan through temp
sensors so installing a temperature
gauge in the radiator is not necessary.
Chassis changes to the two-stroke
XC-Ws for 2018 include revised suspen-
sion and radiator guards that provide
better airflow. The upper fork tubes on
the WP Xplor have a new taper for im-
proved flex and less stiction. The PDS
shock now has stiffer overall settings.
WATCH OUT
ERZBERG!
We split our riding time at Erzberg
between the 250 and the 300, spend-
ing the first half the day on the 250.
Like a fuel-injected four-stroke, starting
the XC-W TPI only takes a push of the
starter button. There is no gas petcock
to turn, no choke to pull and no cloud
of smoke as the bike warms ups. As a
bonus, the TPI bikes idle flawlessly one
hundred percent of the time, it doesn't
matter what the engine temp is.
The 2017 KTM two-strokes were (and
are) great bikes in spite of their finicky
Mikuni carbs. The Mikunis don't work as
well as the Keihin carbs they replaced,
plus the Keihin carbs have better range
when it comes to altitude change.
But that doesn't really matter much
anymore thanks to TPI. This new fuel
injection provides performance equal
to a perfectly tuned Keihin carburetor,
and it does it flawlessly all the time, no
matter the conditions; something a carb
just can't do without manual adjustment
and tuning. With TPI you can twist the
throttle a lot more at low rpms without
loading up or bogging, conditions that
can cause a carb to dump more fuel
than needed, then surprise the rider
with an unexpected hit. Consistency is
the key word when describing the two-
(L-R) The filler cap for the oil
tank is located between the
fuel tank and steering head,
utilizing a hose in the upper
frame tube to deliver the
oil to hidden oil tank. The
key to the KTM's success is
right here—the Transfer Port
Injection system.
