Choke problem?

[Fazer99]

I get a similar thing happen to mine every now and then. I've found that if I have to put a little choke on while the engine is running I have to give the throttle a little blip otherwise it stalls (I think it's because it can't handle the sudden extra fuel intake and just gets strangled, so a little blip pushes it through) if I put the choke on before starting up then it has no issues. When it starts sounding abnormal from this issue, I do like fazersharp stated and give it a good thrashing and so far that has sorted it.