I am new to this site. Anyways I just removed the fuel vapor unit from the trunk of my bv250. Wow what a difference. This process is described on this site for a bv500 but apparently it doesn't affect a fuel injected system to much. The u.s. bv250 has a carb. My scooter has had this problem since I got it, it stalls at takeoff. Since the mod this problem no longer exists and overall it is a completely different scooter. Acceleration is improved and throttle response, I will test the top speed tomorrow. I have done two mods so far both virtually free. I tore up an old memory foam pillow and stuffed the pieces in the seat and this one.