Carb Tweaking '03 XR400

I just put a Big Gun Race full exhaust system on my XR4 and changed the jetting to 60/160 needle clip in the second slot, 2 1/2 turns out on the screw, pulled the snorkel and installed the Uni. I just fired the bike up for the first time since the install and I must say that these mods made an enormous difference. The bike seems to be very strong all the way thru the throttle, and it idles perfectly. My question is when I blip the throttle there is some hesitation...maybe this is normal and just never noticed it on the stock set-up. Is there a way to minimize this or should I just accept it and live with it til I can afford a pumper carb?

I have an XR4 at sea level. I have done all the gordon mods and put on a white bros e-series with six discs. Right now I am running a 62/160 set up with the needle in the 1st clip, needle as high as possible, and 2 1/4 turns out on my mixture screw. The bike runs awesome from 2/5 throttle and up, but I too am experiencing a hesitation and bog when I whack the throttle at low rpms. It always did this before, but I really can't tell if it is better or worse now. The exhaust noise makes it more difficult to compare engine speed from before and after. It is definitely much stronger than before though!

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