i am trying to jet a trx250x which is running lean. it will run for about 4 or 5 minutes and then stall and will restart in a few minutes. the plug did not appear white but the pipe was red near the jug. i went form 128 main to a 133 and got some improved performance and a slightly red pipe but it still stalls after a few minutes. is the stalling due due to the lean condition? also when i changed the needle clip to make it richer i lost the idle. it is as though the idle speed screw is gone. if i turn the screw up it cause high idle until you snap the throttle once and it will drop off and stall. what did i fail to put back together right? appreciate any help
thanks dan

 

very possible its not a carb prob, but a faulty stator which creates your spark, only real way to know is with a manual and ohm meter

 

The funky idle sounds like a vacuum leak.Most common is the seal on the crank behind the magneto.