not starting

The first time I ever started my motorized bike it wouldn't start with the choke ON so I turned it off and it started but would die if I let go of the throttle, so basically it wouldn't idle. Then I adjusted the idle screw and I was able to get it started and idle just fine, each day I would...

I've had this bike for about 5 months now and it been a nightmare, it has compression has spark and I don't know why it's not starting, it turns over but doesn't start. Help?:-||