I have 2005 softail deluxe it starts good and runs good and after 5 mins it starts missing and backfiring. any suggestions what it could be?

 

Carb or injected, any recent work or mods?

 

injected no mods

 

Check the voltage when it is running. Should be over 14 volts. Have you replaced your fuel filter and lines? That would be my next place to look.