XNATEX,
I'm in the midst of building a F2 also. I've not ran mine yet, but have read a few opinions on how to callibrate your bike. I'm going stock engine, K&N filter in airbox and likely Mac or modified Mac exhaust. Have 115s in for the start.
If you're running pods on your bike, you'll need to go up 1-2 sizes. After market exhaust another size. Elevation can also play a factor,(Higher up is thinner air-less gas needed, drop 1-2 sizes...lower elev. opposite applies). I would start with a 120 and work to a 115. If you can find one, there's a 117.5 available that might be just what you need. Also if your top end is good, but you lack midrange punch, try adjusting your needle jet clip. If it's adjustable, move the clip down 1-2 steps. This will have the needle jet up higher out of the jet opening allowing more fuel to flow. Hope this helps.