Sorry for the late reply!! It has got a khien carb on it!! I have lifted the needle up a setting and still hasn't changed!! Also I'm using rock oil in the bike I have changed to putoline to try that and still makes the noise!! I think next step is to take the carb off and see if the jets are clean. How far out should the air screw be (how many turns)? I havent touched this yet but think its one of the nests steps I do us normal fuel not high octane so I shall also have to change the fuel is there anything else it could be?
Thanks to everyone that sent a reply.