Ok, I have a 1996 CBR600F3. Ordered a petcock for it as the previous was leaking. (This bike has been sitting for a few years, btw). The fuel tank has two hose nipples coming off of it. The smaller as I understand it is the vent from the cover.....bowing air backwards, that seems correct. The larger is the tank vent.....also seems correct. The fuel pump has two lines coming off of it - no issues there. But there is a small nipple coming off the side of the fuel pump, and also one coming off the side of the petcock.....what do these connect to?

I accidentally connected the smaller vent line to the petcock nipple, and it ran for a while until it created too much vacuum to run. Now it seems that it isn't getting any fuel, although the fuel pump is clicking when bypassed.

Do the petcock and fuel pump nipples need connected together perhaps?
Thanks in advance...bought her in poor running condition, and she has obviously been bubba-ed a bit.

 

Small line off your petcock is for vaccum to open it - it usually goes into the head somewhere. Small and large vents off the tank, one is a drain line for the space around the fuel filler, the other is the air vent so the tank doesn't create suction as the fuel is pumped out. Both just go to free air usually behind the swingarm.

The small hose on the pump itself is another vent and should exit out behind the swingarm.

 

Awesome, that has to be what I am missing as al the other pieces are in play.
Thanks!