so my buddies bike starts and runs with choke on but as soon as you turn choke off the bike dies. it will run for a few seconds on half choke but eventually dies. I took the carb apart and cleaned everything and it make no difference. I was assuming the pilot jet was clogged. When i got into it the jet appeared to be clogged but i just blew it out and reinstalled it. Is there anything else that could cause this?