I recently put a mivv slip on the bike, The slip on removes the the flapper valve. They told me that I don't need to modify the fueling or change the ecu. When I start the bike in the mornings the bike fires up good but then 5 sec after it starts it dies. I never had this issue before putting the slip on. At first I thought it was the battery but the battery is fine. Is it possible that not having the flapper valve can create this issue?