I have a 1992 GSF250 Bandit. Having trouble starting, battery charged, petrol full- attempts to kick over after a couple of goes put on choke and still wont start. Starts sometimes and not others.

You may have flooded the engine by now, leave the choke off and wind the throttle wide open. Wind the engine over to clear the fuel out. Then turn off, and back on again shut off the throttle. Try to start it without the choke or without opening the throttle. If it doesn't start turn it off and check your air filter make sure it isn't clogged.
Then check your carbs if it has them, slightly tap them on the bowls. Then find the screw on the bottem of the float bowl that lets the fuel out normally an allen head. Unscrew it and allow fuel to run out, then shut it off. Do the same for other carbs. Now try to start it again, if it starts then it was a faulty needle and seat and you might want to look at changing those. If you have a fuel tap make sure it is turned on, make sure you have plenty of fuel in the tank.

Failing that it is a spark issue.