aRacer RC Mini X ECU – Honda Grom SF 125 / MSX SF 125 2016–2020

The SF-generation Grom is still one of the cheapest race bikes you can build; this is the previous-generation Mini for it, at the same price as the Mini XX.

The aRacer RC Mini X is a full-replacement programmable ECU for small-displacement EFI singles. It plugs into the factory harness in place of the stock ECU — it is not a piggyback — and opens up the fuel and ignition maps the factory unit locks away. Tune from your phone over Wi-Fi with the aRacer X-Tune app, or go deeper on a PC with SpeedTuningX through the PRO-LINK adapter.

Every ECU starts with a Quick Burn: it pulls the latest base calibration for your bike from aRacer’s database in about a minute, with free calibrations for the common bolt-ons (exhaust, intake, big-bore kits). Stock and lightly modified bikes run well on that alone. Add an AF2 or AF3 wideband module and the ECU can AutoTune and run closed-loop on your actual engine.

What it does

• Full replacement of the factory ECU; plug-in installation on the stock harness
• Open fuel and ignition maps with rev-limit and start/idle control
• Wi-Fi tuning from the aRacer X-Tune app (iOS / Android) or SpeedTuningX on PC
• Quick Burn base calibrations and free bolt-on calibrations from the aRacer database
• AutoTune and wideband closed-loop with an AF2 / AF3 module
• Real-time engine monitoring in the app
• Works with the R Button, DG2 gauge and Sport D display

Fitment

Fits the 2016–2020 Honda Grom SF 125 / MSX SF 125. Not for the 2013–2015 first-generation bike or the 2021+ five-speed. The ECU connector and calibration are specific to the model and year, so send us your year and VIN if you are unsure.

Setup and tuning

Plug the ECU into the factory harness, connect to it over Wi-Fi with the free aRacer X-Tune app and run Quick Burn to load the base calibration for your bike and mods. For full map access on a PC you need SpeedTuningX and the PRO-LINK USB adapter (sold separately). Heavily modified engines should be finished on a dyno by a tuner; aRacer’s U.S. team can also remote-tune from logs.

Works with

• aRacer AF3 Wideband AFR Module
• aRacer PRO-LINK USB Communication Adapter
• aRacer DG2 Multi-Function Display Gauge
• aRacer R Button
• aRacer Sport D Racing Display
• aRacer Hi Power MAX Spark Coil

Specifications

• Part number: PA-CX088A0
• Platform: aRacer RC Mini X
• Application: Honda Grom SF 125 / MSX SF 125 2016–2020
• Type: Full-replacement programmable ECU (plug-in, not piggyback)
• Connectivity: Built-in Wi-Fi to the aRacer X-Tune app; PC via PRO-LINK
• In the box: ECU with activation details for the X-Tune app (keep them with the bike)

Product images are aRacer’s renders and may show the same ECU housing as a related model.

Closed-course competition use only. aRacer ECUs and race electronics are sold for closed-course competition, off-road, dyno and development use. They are not CARB-approved or EPA-certified for pollution-controlled vehicles on public roads. You are responsible for complying with the laws that apply to you.

Dealer support

Mala Racing is an authorized aRacer SpeedTek dealer. Orders ship from California, and U.S.-based technical support, calibration help and the aRacer calibration database are available through aRacer ECU R&D of America. Not sure about fitment or which accessories you need? Email malaracingllc@gmail.com with your bike, year and mods before you order.

California Proposition 65 WARNING: This product can expose you to chemicals including lead, which is known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov.