I have a 2008 trx 700xx and I just put on a motoworks pipe and a fmf efi unit. I went cruising up the mountain and was fine but when I got to the trails and rode hard and slowed down for somethings and would down shift and get back on it it would sputter and cut off. Only happened 3 times but I didn't adjust the unit so not sure if its off or what. I was thinking it was dumping fuel in the motor and when I grabbed throttle it would do it but other than that it ran like very nice. Then heading down the mountain it was fine also. If anyone has any ideas I would love to hear them and maybe settings if anyone has had the same issue. I do plan to race a little too and don't need it dying on me.