Dont listen to Bozo sorry i mean bonzo

thanks for the warm welcome, problem being fueling i think, bike starts ok, when up to temp, blip the throttle nothing there for slit second then revs pick up, also when in traffic on the very littlest of throttle the engine rev's are fluctuating bewteen 1000 & 2000 revs, wont hold a steady engine speed, it's got the cable connected in the top [air filter] & no servo other end, also as an after market silencer on, make unknown, new to all this stuff so be gentle breaking me in to this, rick, sorry if this is posted in the wrong place,rick,