the fi2000 only adds fuel, it cannot subtract it. the vtx is tuned rich at rpm's above 2000 to 2500. it is lean at the lower rpms for emission purposes. typically the unit is put on to eliminate the low rpm decell pop. if you intend to keep it on the bike, set the first dial at 1 and the rest at 0. the only area that needs a touch of fuel is the low range anything else and you're just wasting gas. good luck and ride safe.