Two-stroke and fuel-injection lovers, the massive day has come! KTM’s 250 XC-W TPI is right here. And to point out the orange engineers weren’t afraid to throw this bike (and a handful of journal take a look at riders) at among the hardest driving on earth, the bike intro was held on the residence of probably the most excessive off-road competitors: Erzberg!
KTM has spent greater than 10 years growing two-stroke EFI expertise for the off-road market as a result of it knew the significance of the bike working completely earlier than it was launched into customers’ palms. Effectively, Large Orange achieved it—the FI two-stroke engine is superior.
The corporate has a 250 XC-W TPI that will probably be out there in the USA this fall. Additionally, along with the 250 XC-W TPI, 250 and 300 EXC TPI fashions can be found in Europe as 2018 fashions. Let’s maintain our fingers crossed that KTM makes a 300 XC-W TPI out there in the USA for 2019…or a 2018.5 mannequin.
The KTM 250 XC-W TPI system begins with the highly effective and confirmed counterbalanced 250cc two-stroke engine. After years of two-stroke FI growth, KTM discovered good efficiency, reliability, and (important in Europe) the flexibility to fulfill Euro four emission requirements with the patented “Switch Port Injection” (TPI). The system begins with a 39mm Dell’Orto throttle physique outfitted with an idle adjusting screw and a separate cold-start gadget that opens a bypass to permit in additional air. Oil is equipped from the automated oil pump and injected via the throttle physique with the incoming air. The Dell’Orto throttle physique doesn’t home a gas injector, as KTM discovered mounting two gas injectors downstream into the rear switch ports offers wonderful atomization of the gas with upstream air. The result’s extremely environment friendly combustion and decreased losses of unburned gas.
Figuring out when and the way a lot gas to inject is all managed by KTM’s engine administration system (EMS). This technique makes use of a newly developed digital management unit together with 5 sensors that decide not solely how a lot gas but in addition how a lot oil to inject. You’ll acknowledge these sensors as: throttle place, coolant temperature, consumption air temperature, consumption air stress, and ambient air stress. Thanks to those sensors and the EMS, there is no such thing as a longer the necessity to manually modify the jetting for temperature or altitude situations.
The 2018 250 XC-W TPI comes with a six-speed wide-ratio transmission, electrical starter, lithium-ion battery, and a extra highly effective generator to fulfill the necessities of the upgraded EMS. Constructed into the EMS is the choice to mount an adjunct radiator fan from the KTM Energy Components catalog that’s managed by the engine administration system.
We began our day at Erzberg at about 2,700 ft above sea degree and headed straight into some tight woods. I used to be stunned our KTM information left us little time for the bikes to heat up. Nonetheless, they ran completely after solely a minute or two of idling whereas I strapped on my helmet and pulled on my gloves.
These trails had been fairly tight, and if this was my private bike, I’d need to minimize down the bar 10mm on every finish simply to offer me a little bit bit of additional clearance. On the plus aspect, KTM has among the greatest hand guards in the marketplace, and I actually put them to the take a look at. I used to be unsure what to anticipate from the engine, as usually FI makes an engine really feel a little bit smoother. I did really feel like this bike was just a bit flat off the underside. There have been areas the place the wide-ratio transmission form of made me need a barely taller first gear or perhaps a barely decrease second. Within the tight stuff, I primarily left the transmission in second and used the clutch extra. This was not an issue, as KTM’s hydraulic clutch is bulletproof. As a lot as I used it, the clutch by no means modified its really feel or hook-up.
From there we started to climb some steep hills with enjoyable switchbacks. I used to be impressed by how simple it was to show this bike up the hills. The TPI engine’s capability to run at an unusually low rpm made navigating some very tight switchback turns simple. One other nice characteristic of the low rpm was stopping and beginning on a hill. Whenever you would usually assume you had been caught or perhaps needed to roll backward, you possibly can simply sit again to get a little bit additional weight on the rear tire and lug the engine up the hill. Wheelspin was very controllable. Additionally spectacular within the tight woods was how this engine frequently appeared to run at low temperature. Our slower tempo within the tight woods didn’t permit for a lot airflow via the radiators, however at no level did the bike appear to be overheating. I’m assured if I had ridden a 250 four-stroke, the coolant would have been boiling.
We popped out of the woods just a few hundred ft above our start line onto a highway main into our first hill climb—Erzberg’s Water Pipe. This was actually a giant climb, however there was no cause to not make it. On my first try, I approached the hill a little bit cautiously in second gear. At concerning the midway mark I used to be pondering I picked too low of a gear, as I believed I’d run out of rpm. I simply saved the throttle pinned and this bike actually stunned me at how effectively and the way far it revved. It pulled me up no downside. We spent a little bit extra time climbing Water Pipe, and I attempted it in third and even fourth gear; third was undoubtedly most well-liked for this hill. We used a reasonably steep part to descend between climbs, and I felt very snug with the chassis. The bike is effectively balanced and steady, and it gave me confidence even because the setting and obstacles tried to take my confidence away. Letting the KTM free-wheel was not a difficulty, and after I was starting to go a little bit too quick, KTM’s 260mm Brembo entrance brake was there to gradual me down.
From there we headed into flowing trails lined with tree roots and smaller rocks. Standing up and pushing my tempo within the woods was simple. The engine felt higher in these trails, as we had been principally in second and third gear. The KTM WP Xplor 48mm fork soaked up the rocks and nonetheless had good hold-up after I was laborious on the brakes. Accelerating over the roots and rocks was snug, because the WP Xplor PDS shock soaked it up with little or no destructive suggestions.
These trails opened up into an space the place KTM laid out a little bit little bit of a enjoyable moto “particular take a look at” part. This was not a motocross monitor; it was extra of an open space single-track with some small rolling mounds the place I might really feel a little bit extra of the suspension motion. Take into accout we’re in the course of an iron ore mine—they don’t have a lot in the best way of enjoyable, quick, sand whoop sections. I did discover in a few of these “particular checks” sections the suspension was a little bit smooth and would have benefited from a little bit extra management. This moto part additionally uncovered a little bit little bit of a flat spot within the engine if the rpm isn’t saved up. And for these occasions once you need to experience it a little bit extra aggressively, the engine might use a little bit extra roll-on torque off the underside.
KTM laid out a enjoyable course via a rock backyard that was perhaps a quarter-mile lengthy. The rocks diverse in measurement from bowling ball to drugs ball. I’d say this is among the sections the place the bike actually shined. I entered in second gear and solely had to make use of the clutch to hold the entrance wheel in just a few spots. The fork handled the sharp-edged rocks with out deflection, and the rear wheel adopted proper alongside with out bouncing out sideways. KTM engineers have the chassis dialed for a majority of these situations. The following particular take a look at part, Dynamite, was arrange for us as a down and again. Simply dropping into Dynamite was intimidating. I used to be actually getting snug on the KTM 250 XC-W TPI; Dynamite was actually difficult, however the bike undoubtedly made it simpler, because it was in its factor.
We visited just a few different well-known sections like Machine after which Carl’s Diner. I believe we might have tried these, however then once more I’d nonetheless be there at the moment making an attempt to make it up, and I knew KTM needed the bike again on the finish of the day. We continued to the summit of the mountain for a fast break, a drink of water, and some photographs. Earlier than we started heading down, I began to consider how effectively this bike was working. Usually, a two-stroke engine is extra affected by adjustments in altitude than a four-stroke. I’d say that at three,500-plus ft of elevation, a typical two-stroke can profit from some carburetor changes and the issues will grow to be much more noticeable each 1,00zero ft from there. The EMS was doing its job your entire means, and as a lot as I’d let the bike idle or lug it, there was no want to wash it out with a fast twist of throttle. Naturally, the engine did lose a little bit energy as we approached the summit (which is anticipated regardless when you have a two- or four-stroke), however it was not even near as a lot as what I anticipated.
Simply once we thought the journey was over our information knowledgeable us we had been happening Elevator. As soon as once more I used to be glad the 250 XC-W TPI was simple to experience. The brakes had been good and the suspension was very forgiving. These had been among the steepest, rockiest, longest downhill switchbacks I’ve ever ridden.
On the finish of the day I’d ridden this bike for about 5 hours and climbed from 2,700 to four,700 ft and again down. At no level did the TPI system do something however run flawlessly. The bike by no means overheated through the 75-degree day. I abused the clutch and it by no means pale, and because it hit big rocks the pipe was nonetheless in excellent form. I’d say this can be a huge step in bridging among the gaps between two-stroke and four-stroke bikes. KTM’s laborious work has helped enhance a number of of the two-stroke weaknesses. It gave up little to not one of the two-stroke advantages and integrated among the options I like concerning the four-strokes. This inventory bike managed the Iron Large rather well.
As for Erzberg, it was eye-opening. I take pleasure in driving and racing and revel in a problem. I’ve a newfound respect for the riders who end the Erzberg Rodeo. It’s on my record of high 5 locations I want to return to, however as for racing there, no means. Belief me after I say that place is not any joke.
- No must jet the bike or combine oil
- Constant really feel of the engine and throttle response no matter altitude
- Very simple, mild, and nimble to experience in tight trails
- No want to hold premix oil on lengthy weekend rides with fuel station fill-ups
- Engine is a little bit flat off the underside
- Suspension is a little bit smooth on greater hits
- The 300 isn’t coming to America this yr
This text was initially featured within the August 2017 print version of Dust Rider.