Pro Bike: KTM Pro Racing’s fuel injected 125 two-stroke
Yes you read that right, a fuel injected KTM 125 two-stroke exists and it’s racing in the EnduroGP World Championship care of the KTM Pro Racing Sport team. Enduro21 takes a closer look…
The first EnduroGP of the 2023 season showcased a fresh batch of factory bikes across the sprawling paddock in San Remo. Wearing our paddock spy hat, coat and carrying a camera, Enduro21 scoped the race tents and awnings on the Friday before racing began and came across this little gem of a 125 in the KTM Pro Racing Sport camp.
The Pro Racing Sport Team is the junior, or second arm if you like, of the official Farioli factory team (spot a Farioli sticker on the front headlight and you know it’s a sweet bike). Andrea Verona and Josep Garcia, plus Billy Bolt at this GP as well Mani Lettenbichler and the KTM, Husqvarna and GASGAS factory teams in Hard Enduro World Championship all run under that overall management.
This Pro Racing Sport Team has plenty going on in terms of talent with Mikael Persson racing the 2024 300 two-stroke Husqvarna and young Manuel Verzeroli on this 125 fuel injected two-stroke in the Youth class.
The link to the KTM Group factory in Austria is a strong one and often these bikes under the radar testing and developing the production bikes we’ll ride next – plus, the factory boys Garcia and Verona have moved to 2024 machines already.
But this bike is something special, a 125 without a carburettor no less which the team were more than happy for Enduro21 to photograph but weren’t able to talk openly about some of the parts fitted. So some of this Pro Bike walkaround is with the help of the team but some parts – mainly the engine – is us talking no them!
KTM Pro Racing Sport 125 Enduro special in detail
The team use the Cone Valve forks with SKF seal and dust covers. The whole fork is set quite soft, and the rider, Manuel Verzeroli uses his own setting with 3.8 springs because he’s really light and likes a really soft feeling. “Even for enduro it’s quite soft compared to others” explain the team.
The forks are mounted on Geco Special Parts triple clamps which have the same off-set as standard (22mm). The CMD handlebar mounts are on Geco clamps which are also as low as possible (30mm) with Renthal grips and a Domino throttle housing for extra strength.
Based on the SX 125
This enduro bike is based on the 125 motocross model, so the rear suspension is a linkage type not a PDS set-up as you’ll find on EXCs.
The WP Trax shock has a 39Nm spring and a “specific setting for the rider” which is like the forks and “really soft”.
Eagle-eyed readers will have already spotted the handlebar has a map switch. This bike has an ECU with two maps installed developed specially for this bike, to make the bike richer or leaner.
“We use fuel mix right now at a 3% because Verzeroli likes an engine which is suffocated” they explain.
The exhaust header is the standard one in the motocross bike with the saucy, stubby Akrapovic silencer.
They use the standard radiators and fuel tank from the SX model also. If the enduro race has a long transfer between refuelling points they can fit a clear EXC tank if needed.
The seat is also quite soft, but when asked they explained it was just like the standard one really.
KTM Pro Racing Sport fit the Rekluse clutch cover with the same oil capacity but it’s stronger than stock part. The clutch isn’t an automatic one by the way, they use the manual Rekluse internals.
The stator and the flywheel are special for this bike to make lights work etc. “We fit a special electric wiring system for this bike that came directly from the factory in Austria.”
“The flywheel is a bit heavier than the motocross one and the weight of the stator is additional also, you really need these special parts to make this bike work.”
What about that FI engine then?
The engine is completely standard they tell us, “we just pulled it apart and build it back together with special care on the process and making the tolerances lower.”
The most important things are the crankshaft which is built with minimum tolerances, “it has an almost perfect balance.” The exhaust valve also has been carefully worked to minimize the tolerances.
Quite obviously the engine is very special part in itself though. Fuel injected 150 two-strokes we’ve seen before now but a fuel injected 125? This is new from KTM.
Under instructions from the boss, Fabio Farioli, and the KTM factory, we weren’t able to get anyone to tell us much detail but Enduro21 could see the throttle body was standard, with two injectors and clearly not a TPI-type.
All of which means, without too much detective work, we can expect a throttle body fuel injected 125 as a production bike soon. Obviously they exist in the larger capacity SX and EXC ranges but we take this as big news that KTM is honing in on a new, carb-free 125 two-stroke for racing and therefore more compliant with emissions restrictions and homologation. The 125 is not dead!
The team fit the KTM Powerparts skid plate plus the brake lever, gear lever and footpegs are standard from the motocross bike.
The front wheel uses the A60 Excel rim with the anti-mud profile with stronger spokes to make the wheel stronger. Intec brake discs in both front and rear are the same size as standard but the front rotor is floating and the rear is slightly thicker than OEM.
It’s the same at the rear with an A60 Excel rim with the anti-mud shape and spokes. The rear brake disc is the same size, just thicker and with a different design which improves power.
The rear sprocket is from Superprox and from the Powerparts catalogue with a Regina chain and an Acerbis chain guide. They run a 13-52 final gear ratio, “we sometimes change to 51 and go shorter than standard”.
The KTM Pro Racing team counts Acerbis as a sponsor and partner but all the plastics come from the Powerparts catalogue at the moment Acerbis can’t produce the new kits for these bikes.
“We already have the license plate holder from the 2024 bike, because this is the bike of the future!”
Other unique details include the welding of a plate to the chassis to accommodate the side stand. It’s the one you’ll see in the 2024 EXC bikes they tell us but so far no frames exists with it fitted.
On that note, KTM already told Enduro21 when we tested the 2023 SX models that the overall plan is to use common frames across all machines, homogeneous production and all that.
The plan is to produce some of these 125 special editions for customers, “around 20-30 so it can be sold to the guys who want a latest generation KTM enduro bike”.
Contact KTM Pro Racing Sport for more on that one.
Photo Credit: Future7Media