my dad has a 2001 rancher that is running like crap. i have taken the carb apart many times and cannot figure it out. backfires on decell and backfires through the carb occasionally AT idle. What could this be? i have tried adjusting th eidle air screw to no avail thanks

 

check valve timing and specs. could be a valve spacing out of adjustment or worn cam lobes.

 

Sounds like you are lean on the bottom, and that is typical of a clogged pilot jet. Most folks "clean" the carb, but neglect the pilot. Just replace it if necessary....

 

i cleaned all the jets and took out every screw in the dang thing. i am pretty sure this wheeler does not even have 600 miles on it so i doubt the worn lobes. It ran good beofre it sat for about a year and now it runs like crap. i replaced the bowl gasket and o-rings.

 

This is classic....it sat for a year, so the fuel dried up and gummed up the pilot. You may think you cleaned it well, but I have my doubts. Just replace the pilot with a new one, and then readjust the fuel screw....