Ok so i take it this is the NT speed carb. The red air filter cap one...
My story short..
Had two identical bikes with stock carbs, changed one out to speed carb , ran like **** for about 2 or 3 weeks, then started kicking the other bikes ass.
Bought speed carb for other bike, bike ran like **** for a month and then last night, the other bike couldnt keep up with me. lol
Its just one of those things that your engine will like right away or will take some time getting used too in my opinion. I dont have air leaks.
One thing i did notice is when your throttling off the start and its bogging... pull your choke up just to the point where you feel your engine grab all the power... then as you accelerate put the choke back down when reaching top speed... i do this when racing my bro and i rip by him and he doesnt know why lol. you might have to do this for about ten mins... all depends on the weather right now.. anyways whether its right or wrong, thats my two cents.