200X Carb question

[85 200X]

I have a 85 200X with a UNI filter and a Cobra aftermarket exhaust. Ever since I've owned it if I punch the gas hard it will miss and sometimes stall. It does this if the engine is cold or if I have been riding for a hour. It is not too bad on the trails but sometimes it does miss if I really hammer on it. When it is sitting and idleing is when it is really bad. I have tried adjusting the jet needle and the air screw a number of times and it never gets and better. The engine runs great and the plug is nice and brown with a little black on the edges. Does it need jetted, if so what size? Or is it something else? Thanks

[BLAZERONE22]

I just spent all day messing with mine its an 83 I put a Dg pipe and a unifilter on and it would'nt idle without the choke on, TimSr on the board told me my Slow jet was plugged and it was. I rejetted mine today with a 112 main up from the 110 the 115 was a little much, but it sounds like yours running fine as far a color on your plug, my needle is set in the middle groove. If you have it apart you might check the slow jet, I think its a 40 main costs about 5 bucks. Hope this helps good thing it only takes a minute to pull the tank and the carb. Have fun! :D

[BLAZERONE22]

oh and set the air screw on the right side of the carb I think thats what dials it in when you blurp the throttle.