What do the 2 vent hoses on the carb. do, and what are the symptoms if one of them was clogged?

The reason I ask is last Friday on my way home my bike started acting like it was running out of gas so I switched to reserve (mine has a raptor petcock) and it didn't make any difference it still died.  So I pushed it to the gas station and when I took off the gas cap I could still see fuel in the tank and it was at a level where the reserve pickup would have been submerged but the bike wouldn't start, I filled the tank up and was able to ride the rest of the way home.  Last night I drained all of the fuel out of the tank first from the on position until it stopped  flowing and the switched to reserve and the tank was pretty much empty, so I took the vent lines off of blew into both of them and one was clogged with some kind of bug.  So would one clogged line cause my bike to not run with low fuel and the tank set to reserve?

I put a rubber boot over one and let the other one vent. If you open the float bowl you will see that it is just two unrestricted passages to allow air in and out or let's it "vent"

So i opened the gas cap and it shot air and gas out as a mist as i was taking it off..not venting? if so how do i allow it to vent with the cap on?? also my bike keeps dieing at a certain rpm...over and over please help meh!

ok real fast before i get blown up....so it was stock when we bought it and it ran fine...buddy road it on the POW-MIA ride awhile back was aloooooong day and aside of it making a VERY loud pop when turned off...it ran fine.
SO since then i put a cone air filter on it and a raptor petcock, 0.55 pilot and 152.5 main(i think) and of course capped the vacuum inlet on the carb...
bike boggs down and dies, can hear fuel gurgling off and on as the bike is OFF and just sitting there...air box was full of gas? only thing going to the airbox is the breather hose from the carbs....and the breather from the cylinder head...anyway so yeah wtf is going on? I dont understand it and am thinking i should revert back to stock!

becca wrote on 07/26/13 at 17:02:40:

Sounds like you might be a bit rich...  I'd try a #150/ 52.5 combo...

As far as the cap... you can try soaking it in carb cleaner, but that's expensive... I'd take it apart and spray clean it...
...(or, if you have a compressor... spray some cleaner in the keyhole, and blast some air through it)...
Best luck...

Yup,... except Cali models... they have a tube going to a filter canister...
So, those caps don't vent...
You in Cali?...

Ooops... sorry Bec,... I missed a part of the post...
Fuel in the airbox...
You had a stuck float... it might not happen again,.. if it does, you can sometimes free the floats by tapping the bowl with the handle end of a screwdriver... if it happens too often,.. you need to pull the bowl and see what's up... They could be sticking, not floating anymore, or the float needle/seat could be dirty or dried out...

I had the same problem with gas in my air box. It was also coming out of my vent Ports on the carb. I got a new float needle (<$30) and that completely fixed that issue.  It might be dying because it's too rich?