I have a slight sputter when I'm just going up and down my street at in between barely any throttle and 1/4 throttle. You know just cruising at around 5-10 mph. Any theories?? I know its a carb issue and a slight one at that. My carb setup is airbox with no lid. K&N with plate, 170/175 mains, 25 pilots, screws turned out 3 full turns each.