Tune It or Flash It? What's the difference

A fuel tuner is a device that is installed between the engine's fuel injection system and the ECU (Engine Control Unit) to adjust the air/fuel ratio and other engine parameters. It essentially modifies the signals sent to the ECU, allowing the engine to operate more efficiently and produce more power. Fuel tuners are often used for simple modifications, such as changing the exhaust or air intake system.

An ECU flash, on the other hand, involves reprogramming the ATV's ECU directly. This requires specialized software and hardware to access and modify the ECU's programming. ECU flashing allows for much more extensive modifications to the engine's performance, including changes to the fuel injection, ignition timing, adjusting fan on/off temperatures, and much more. It can even be used for more complex modifications, such as installing a turbocharger.

Overall, while both fuel tuners and ECU flashes can improve an ATV's performance, the main difference is the level of modification that each allows. A fuel tuner is generally used for simpler modifications, while an ECU flash is required for more extensive changes.