15-16 HONDA TRX500FORE: HMF Gen 3 Optimizer With technology changes, most engines that are release these days have an electronic fuel controller system. With the use of an electrical fuel controller, you are able to accurately pinpoint the perfect settings for your motor. HMF Fuel Controller uses the latest GEN III technology and is pre-programmed with the best settings for your engine. If you need to make adjustments according to your riding style, simply use the fuel controller to make your changes. Pre-programmed with the best settings for your HMF exhaust.