w.o.t. carb problem

[skull2002]

just last couple rides, i have noticed that whenever i go wide open on throttle, it starts to sputter and miss really bad, and almost dies altogether. i was wondering if needing valve adjustment could be part of the reason. carb was jetted dead nuts and ran great before. i have pre filter on k&n, but run sand and water a lot too, so thought maybe main might be plugged, or possibly vibrated loose. i do get a few puffs of smoke from exhaust also when it cuts out. have w/brothers rev box, so i know im not tappin rev limiter. has to be the carb im thinkin. anyone have this problem b4?

[F-16Guy]

Your filter may be clogged, causing the air/fuel ratio to be overly rich. I had a dirty filter and went riding in the mountains, and the combination made it run like crap. Once I knocked the majority of the dirt and mud off (didn't have stuff to clean it right at the time), it ran much better. Cleaning the filter would be my first step.