Thanks guys for all the help. And for those interested to know what it was... here's the story LOL :

I was pretty sure it was a faulty stator, because the battery wasn't working (the idea was to swap the stator). Well, I have a spare F4 engine, so I took all the bolts out, took the stator out. Then I proceeded to take the fairing off the left side of the bike, took off all the bolts out from the stator on the bike, then tried to unplug the cable of the stator... and guess what?! It was tucked in where it was supposed to but it was unplugged all this time. So my bike was running straight on a battery before!! And all this unneccessary work kind of sucked... but at least now everything is good. The bike runs like new!!

 

good stuff!

 

Right on man! Have safe rides this summer!

 

Yea that was going to be my suggestion. when you have the choke on when the bike is warming up or whenever you hold the rpms above about 3k, the battery should be reading about 14v because the stator is charging it... Good diagnostics and congrats on solving your problem