I have a slight knocking on my f4i, i hear it faintly at stoplights when i listen carefully, the bike is usually in neutral at longer stop lights and i hear it then aswell.
this is my...boomstick!
Could it be....the evil cam chain tensioner! Eeek!
Then again, check your oil level. A recent experience I've witnessed has encouraged me to remind people about that.
Well i am putting in a new manual CCT tomorrow and also oil change with synthetic.....it should pur like a kitten!!!!