I just bought a used 2002 Ninja. It takes a while to start up. And when it does start up, I need to use the choke or the engine will die. It does this everytime I start the bike. And when I closed the choke, the bike died. Then it would not start at all. I can hear a clicking noise and I need to wait about 30 minutes before the bike can start again. What do you guys think the problem is?

 

first start with the simple things, is the idle adjustment correct? (14-1600 rpm)
if that doesn't do it, check the throttle grip play, if that doesn't do it, check the choke cable to see if it is adjusted correctly, then the carb snch. If none of this does it you may have a jet or valve issue.
How many miles are on it and do you know what maintenance has been performed?