I am new to the fuel injection system. Do you have to get a powercommander or something like that? when you add a full exhaust, air filter kit and a 15t sprocket or can you add this stuff and be done with it. I dont understand what it does thanks.
Yes, you need to modify the amount of fuel when you modify your engine with exhaust, intake,cam,head work, etc. Most people get a fuel controller that they can adjust when your get new stuff. Or you can get a Yamaha dealer to change it also.
Basically the fuel injection on the raptor only reads air temp and density (altitude), and compensates the fuel delivery for that. If you add an intake and or exhaust it doesn't recognize that there is much greater volume of air and won't compensate for that. So lots more air + same amount fuel = LEAN. Tried to make this as basic as I could to help you understand.