What is your approach to starting the bike? Do you use the choke? Do you leave throttle closed, open or somewhere in between? I find the choke and no throttle needed until you sense its firing then open throttle a bit.

Is your battery fully charged? You might be seeing a spark, but it might be weak.

Have you looked to see if plugs are wet or dry after kicking it over but not starting? If very wet you are flooding the engine. If dry you may have a clogged idle jet.