The Ole YZ400 Idle Problem

So I have read and searched and read many posts about a problem I am having but I have not yet figured out what I need to do....

Problem:Bike has never held a good idle or would hang at a high idle and then die down and stall..I recently replaced valve seals and when I was in there saw my valves were way tighter than Spec. called for. I shimmed them back into spec thinking this was my problem and get it back together and same thing. High hanging idle and erratic running. I have messed with the fuel air screw on the bottom and cleaned the carb,checked for ANY air leaks and no good...I am getting frustrated the more time I spend on it :smirk: and I am trying my best to get it right...I unplugged my TPS this morning and it did alot better than it had.The problem now is it will idle and after a little bit(approx 30 to 45 seconds) it will die on down and stall...I am no mechanic but I still cant figure what the problem is,I wanna think it is the TPS but it still will not idle very long(although better than it was)Has anyone had this problem and resolved it?

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