Replacing gas line and filter

[NorazDad]

This is an 81H with the stock Mikunis. PO had installed a clear fuel line with a plastic fuel filter. Due to the crazy configuration of petcock and the position of that dual fuel connection for the carbs, there was a small kink in the line. When I opened the petcock, I always saw gas flow.
I bought and installed a new clear reinforced gas line and glass filter. But when I opened the petcock, no gas would enter the line. Do I need to bleed the line by draining the carbs?
What is going on? Will the carbs and engine start the fuel flow when I try to start the engine? How long will that take? I'd hate to exceed the 45 seconds allowed for the Pamco, EAdv and the high output coil.
Should I just keep cutting back the new line and testing it till the gas flows?
This should have been simple.
Thanks for your help guys.

 

[XSLeo]

On the 81 it has a vacuum operated pet cock. Is has no off position, it has an ON, RES and PRI. In the on or reserve position gas only flows when the engine is running. In PRI or prime position gas flows even without the engine running. This position is used to ensure the carbs are full of gas when starting. Mostly after the bike hasn't run for awhile. Once running move to on.
It possible that the stock petcock was changed to a standard petcock with OFF, ON, RES.
Most bikes won't show much fuel flow without the bike running. When the bikes not running and the float bowls are full, the float closes the float valve a tries to stop the flow of fuel. So no fuel flow. Don't worry about it until you start the bike, Even then you might not see the fuel filter get completely full.
Leo

 

[NorazDad]

Thanks
I was freaking out a bit.
I'll just try it with the new set up
Peace, Bro

 

[gggGary]

Even petcock on prime air will stay trapped in the line till after you run the motor, SOP. The gas will flow past the air bubble, it's just not visible in the murky line. The air bubble is trapped by small passages and screens in the petcock, shaking will let it escape when the motor runs.

 

[NorazDad]

Thanks
Got it.
May have had too much line at first.
Runs great and looks cool too.
I can't thank you guys enough.
Rob