Say if i start it up and i let of the choke to early/much so it stalls, just from those 30 secs of running will be enough to cause it not to start again without bump starting it (good job my driveway is on a slope :p), but even then it take a bit to get it going.
It will spin over a few times, then act like the battery is flat turning over very slowely and eventually not atall.

Can anyone think of why it must do this after such a short time?
Everything else is fine (apart from my downpipes :smt013 ), i can't see why it would do this.