KTM SX-F: Motocross Mapping for More Pull
KTM 250, 350 and 450 SX-F (2014–2015) with Keihin ECU: what a motocross map changes, which model years fit and how to order.
October 25, 2026 by Leo Efimow
On a motocross track, throttle response decides. Coming out of a corner you want the engine to drive immediately and cleanly, without a hole and without stumbling, and at the end of the straight it should not run out of breath too early. A KTM SX-F is a competition bike from the factory, yet even here the software is a compromise for riders of every level and fuel qualities worldwide. On the SX-F models of 2014 and 2015, a Keihin control unit sits under the seat, and its maps can be calibrated in a targeted way.
Which SX-F models fit
The SX-F models with Keihin ECU 812.41.031 (KTM part number 81241031100) can be configured online:
| Model | Years | Displacement | Stock (approx.) |
|---|---|---|---|
| KTM 250 SX-F | 2014 | 249.9 cc | approx. 42 hp / approx. 27 Nm |
| KTM 350 SX-F | 2014 | 349.7 cc | approx. 55 hp / approx. 40 Nm |
| KTM 450 SX-F | 2014–2015 | 449.3 cc | approx. 58 hp / approx. 48 Nm |
| Husqvarna FC 250 | 2014 | 249.9 cc | approx. 42 hp / approx. 27 Nm |
The 450 SX-F is included in its Factory Edition too. The 2014 Husqvarna FC 250 uses the same engine as the 250 SX-F.
Important: the SX-F from model year 2016 has a different control unit (79041031000). The configuration does not fit these models. The safe check is the sticker on the ECU: the second line must show a number starting with 812.41.031.
What a motocross map changes
The power increase revises the ignition and fuel maps. With a motocross engine it is less about a single peak figure and more about the curve: how directly the engine reacts to small throttle openings, how cleanly it pulls from low revs and how evenly it revs into the upper range. These are exactly the areas adjusted in the tables.
The file is matched to the read-out original software of your ECU. You choose which fuel: Super 95 is the safe choice if you cannot always get Super Plus. The Super Plus version uses a little more ignition advance and then requires 98 octane every time. Race fuel calibrations are not part of the options.
We deliberately do not quote extra horsepower. On motocross engines the numbers depend heavily on maintenance condition, operating hours, exhaust and air filter.
Sound functions on the track
Two optional functions are added that are above all one thing: loud.
- Pops & bangs: crackling and popping on the overrun as long as the throttle stays slightly open. With the throttle closed it is mostly quiet; at high revs it can still pop. Strength 1 to 5, from quick and light to slow and strong.
- Party mode (hard cut): at the rev limiter the ignition is cut and the timing retarded; fuel keeps flowing. That gives bangs and flames. You set the sound through the hysteresis, from "brrrrr" to "boom boom". The stock cut-off stays above it as a safety net.
Party mode depends only on engine speed. So it is active whenever the engine hits the limiter, regardless of gear or speed. If you only want it some of the time, put it on its own map with multi-map.
Multi-map for training and racing
With multi-map you spread the options over the four map banks. For motocross, for example:
- map 1 stock for heavy, deep ground or beginners riding the bike
- map 2 power increase for normal training
- map 3 power with pops & bangs
- map 4 power with party mode for show runs around the paddock
To switch, you need a map switch. KTM's stock switch (77239974200) works and reaches two maps from the handlebar: map 1 and the one selected on the rotary switch for the base setting. For all four maps directly there are our switches Stealth (rotary switch, not waterproof) and Clean (aluminium handlebar switch, IP67). Both are in development and can be pre-ordered. For motocross with water crossings and pressure washers, Clean is the more sensible choice.
Cost and process
| Variant | Price |
|---|---|
| one option, always on | €150 |
| several options, always on | €200 |
| multi-map, 4 freely assignable maps | €230 |
| map switch Stealth / Clean (with multi-map) | +€40 / +€80 |
You configure in the motorcycle configurator and choose whether you bring the bike to Stödtlen or send in the ECU. On site we read and program it directly. By post it takes about 3–7 days in total including shipping. The model page with all data is available for example for the KTM 450 SX-F or the KTM 350 SX-F.
Stress and maintenance
A motocross engine lives with short service intervals. A software calibration does not change that. Stick to the intervals for oil, air filter and valve clearance; with more power, a worn engine shows its wear sooner. Pops & bangs and party mode mean unburnt fuel in the exhaust. That adds load to exhaust valves, header and silencer, and the packing in the silencer burns out faster.
An SX-F is a pure competition bike without road registration. Still: all functions are intended exclusively for motorsport. On practice tracks with noise restrictions, party mode in particular can cause trouble, so clarify it with the operator first. More in the motorsport notice.
Conclusion
The 2014 and 2015 KTM SX-F has, with the Keihin 812.41.031, a control unit whose maps can be calibrated cleanly. A motocross map aims at direct response and even pull. Multi-map separates the characters so you have the right map for deep ground, training and show. Mind the model year: from 2016 a different ECU is fitted. More on the hard cut in the glossary under hardcut limiter.