Your air fuel mixture is off I bet you're not running full airbox and snorkel are you?
These bikes were jetted to run for restrictive airbox and snorkel otherwise that air fuel mix is off you will need to upjet your carburetor if you have any different Airbox/filter or pipe combination then stock .
You need to post your whole set up. Is it kitted? is it stock ? what hp? what pipe ? what carb ? what timing etc.