The bike idles at 1300rpm and when you pull the choke it quickly dies down to 1000rpm and then slowly rises to 1600rpm, it should go to 3000rpm. But when you rev the bike and release the trottle it fall to 3000rpm where the choke should be. As you push the choke in it falls to the idle revs of 1300rpm and when you pull the choke out again the same thing happens, it quickly dies down to 1000rpm and then slowly rises to 1600rpm. I have cleaned every part of the carby and used fresh fuel. When the bike is idling I have used compressed air down the choke passage of the carby and the revs increase.