do you have to turn the key off then back on before it starts? my old 600rr did this to me. i would ride a long just fine and when i stop and idle or just take off, it would die. it wouldnt restart unless you turned the key off or hit the kill switch, then turned it back on. i tried everything and no luck. finally i removed my pcIIIusb (not as easy to get to as a busa). that solved my problem. i called dynojet and they told me to sent it in. about a week later a new one showed up and it never happened again.