I'm also having this problem, my bike has always ran good but the past few times I tried to ride it I just gave up.
My engine was also "turning over" but it never seemed to spark and give power, I also noticed that it is hard to get the fuel filter to fill with gas, only a lil.
My guess (for me) is that the kit filter that goes in the gas tank might be clogged and that is what I will search for tomorrow.
Good luck with you're problem man, I want to hear what it is not cranking you're bike.