I recently purchased a used 2004 Yfz 450 that hasnt been run in a couple years. I put a new wiring harness and battery in it and atempted to start the engine. Although i managed to get the engine to fire I could not get it to idle or run smoothly. I had the carb apart and checked the jets, they are all clean and in place, I have been told to check the fuel mix screw at the bottom of the carb but i do not no how many turns to turn it back out. The bike has a Sparks exhaust on it and pro-flow air filter. Any help would be greatly appreciated.

Turn the screw all the way in the turn it out 1.5 turns

Sometimes for me when I get a used bike that has been sitting for a long long time, one carb cleaning does not do it.  That old fuel just does a number on the jets and passageways all through the carb.  I would take it off, go through each jet and passageway again very carefully.  Sometimes new jets do it and they are just a few dollars each.  I also blow compressed air through all passageways.  Use a good grade of cleaner on the carb but try to keep it from getting on your carb rubber parts or you could have additional problems.