04 600rr problem help!
 

I have a 2004 CBR600rr and I bought it used about 10 months ago. It was in my garage all winter only started occasionally and had stabilizer in it. I was at college so I was unable to run it frequently. Every time I ride I am unable to take it past 10k rpm or it will bogg down extremely hard. Never had a problem stalling but as I ride it just gets worse sometimes allowing me to 6k rpm only. Sometimes it runs better when I fill it up with gas even if its not low. I use high octane and performance stabilizer in it. Someone please give me suggestions or help me understand whats wrong - my first bike. Thank you.