If it's a vacuum petcock it has two rubber hoses attached to it. One is usually the larger diameter one that runs to the carbs.mannafanna wrote:
How do i apply vacuum to the petcock?
The other is usually smaller and runs to cylinder head or possibly to the side of one carb.
Disconnect that one at the carb end and suck on it (unless you have a handheld vacuum pump) and see if causes fuel to flow freely out the gas line.
You also should not get flow thru that hose into your mouth (either air or gas). If you can continuously pull air thru it that means the diaphragm is ruptured anh vacuum is not opening the valve to let gas flow.
Other - could you explain more about what is meant by "the carbs were cleaned out."? How? Chemical on the bike? Removed from the bike? By you? By someone who does this all the time? Disassembled? Or just the bowls removed and carb cleaner sprayed?
What I've learned over the years is that often the reason for your current problem is related to the last thing that was done.