So I just bought a 2006 kfx 400 and took it out about three times so far and now something seems to be going wrong the quad will start and run fine for a few minutes and then just die. I checked and changed out spark plug, checked air filter (fine) but as I was messing with the trunk coming off the carb noticed when I pulled that off Atv ran fine, as soon as I put it back quad died. There’s also a smaller vacuum line that goes to a black box that also goes to top and bottom of motor well when I disconnect it quad runs also. Any help or suggestions would be awesome, also does anyone know what it’s called????
please please help.