400ex no top end

[Dezzle]

I have a 2003 Honda 400ex rejetted it last winter, put a slip on pipe nothing special but after a few weekends of riding it I lost my top end the bike starts and drives but when I give it throttle it bogs way out not sure what to do anyone have any suggestions?? Thanks in advance!!!

[davefrombc]

My  first guess would be  a faulty  accelerator  pump  (hole in diaphragm ?) but  also  look  for  an  air leak, or lean  run  from a  partially plugged  jet.  Try  adjusting the  air bleed  screw.  It  may  have turned out  on its  own.