I'm sure this has been asked a 1000 times, so will lay out the setup first:
2005 crf 50 with TB 88 Kit, Race head, 20 mm chinese carb that came with kit, foam filter that came with kit, TB cdi box, pro circuit t4 exhaust.
Bike idles great, and has wicked top end.
Sputters (not bogs) when...