quad runs bad

[BKo]

my quad started to run bad and got worse so i changed the spark plug solved nothing when i get on it it just cuts out and backfires if i slowly get on it it will go but as so as i start get into it it cuts out and runs horrible i pulled the carb out and cleaned it then but it back to gether idels great but still runs bad. not sure what to do any help would be great
my quad is 2001 400ex 440, hot cam 1, cs x-6, k&n,


thanks

[400exrider_88]

mine kinda has the same probelm, people said it might be the jetting, running on too rich of fuel

[Honda#4]

might be time for a rebuild