no gas flow

seems like im not getting any fuel. pours out of the petcock set on PRI. checked the vacuum hose, tube itself looks fine and is not clogged. bike wont start and just sounds like its not getting gas. before i go tearing into anything, what would be the main causes of a lack of fuel flow?
thanks

 

Put a piece of hose on carb 1 or 4 drain oulets & open that drain screw to see if there is any fuel in the bowls. Do them both as I had a needle stick closed recently & that bowl was empty but the other 3 were Ok.

 

put the fuel line from your petcock into a bottle/container, then put another hose on the vacuum port of your petcock and suck on it gently, if fuel flows into the container, your petcock is working, and the problem lies in you carbs

 

i really wish my garage was at my house and i could go try that right now. have to wait till tomorrow but i will try both of those ideas.

 

It is possible that the waffle washer is out of place in the petcock. It is located behind the lever in the petcock. Disassemble the valve and check the alignment of the washer.

 

Fonz, have you checked for spark? What makes you think your not getting fuel? It could be as simple a sticky kill switch or ignition switch. Clue me in if you could, I'd like to help you nail this one.

 

lostboy: brand new OEM petcock installed on friday with an extra fuel on/off switch. old wave washer was shot and the old petcock was in bad shape, seemed cheaper in the long run to just replace it.
Robert: spark is there on all four cylinders. leaning towards a fuel issue after looking over things. battery is good, spark is there and it had started right up and ran for a few minutes then just gave out and wouldnt restart. im still a beginner when it comes to bikes but ive worked on cars before and it just sounds like it isnt getting gas. discussed it with some more knowledgable friends over some beers saturday and they all agree that it sounds like a fuel issue. could be wrong but thats what im leaning toward.
as always, appreciate all the help.

 

Make sure the vacuum line going to the petcock is rated for vacuum use or that the line is not split not allowing the vale to open.

 

its the same hose that was on the bike when i bought it a few months ago and worked fine up until now. checked it for leaks just by blowing into it and covering the other end. didnt seem to have any leaks or cracks.

 

tested petcock by sucking on vacuum line (insert jokes as you see fit) and gas flowed. outside carbs had gas in bowls. took the carbs out and one of the slides or slide pistons was stuck. other three moved up and down no problem but numero uno only went up a little and would stick. im gonna polish them all with some scotchbrite and clean all the jets and everything while i have them out. anything else i should look for while im cleaning them up? may not get to them again until the weekend, sucks but other things to do.

 

still wont start. just cranks and cranks but wont turn over. thinking about trying a new set of plugs but i got no idea other than that. Robert, how would i go about checking for a stuck kill switch or ignition switch?