Ok i just jetted my buddies 450 and just wondering if its normal from idle if you just mash the gas for it to kinda hesitate for a second then pick up rpms it aint running lean i put 170 mains and 45 pilots with the air fuel screw out 2 turns has hmf carbon fiber exhaust and um air box with no lid just wondering what this could be? and when you shut off the quad it smokes out the exhaust for a minute it has not been driven yet less then 5 minutes on the motor

 

If you check on some of the other Yamaha forums you will find that the hesitation is very common, I did manage to get rid of it on my YFZ (changed to a Lectron 44 carb)

om