Hey everyone got a problem with my brothers bike. He asked me to do some work, fork seals, chain sprockets etc but then decided to tell me it wasn't running properly. It would only run on the choke and wouldn't tick over, as soon as you touched the throttle it would cut out. I drained the carbs and removed them and gave them a quick clean made sure the jets were all clear. Refitted them and couldn't get it running. After leaving it overnight it fired straight up and revved really high for 2 seconds then wouldn't fire again. If you leave it for a period of time it will start or attempt to start for a couple of seconds then nothing. It does turn over and spark fine it's just not getting fuel.  The float chambers are full of fuel. Any help much appreciated .