Installing new petcock

[snakemeister]

 I'm about to install a new petcock on my '97 Valkyrie tourer.It's about to turn 100,000 and I've been doing lots to head off a breakdown[fuel lines, brake pads and brake fluid,headlight bulb,rear tire,ect.]
   Anyway, I know the carb bowls are empty as is the gas tank and has been for about ten days.
When I put that new OEM petcock on it what's the best way to prime the carbs without grinding on the starter?

[98pacecar]

Do ya have a mityvac?   

https://www.google.com/webhp?hl=en&btnG=Google+Search#hl=en&q=mityvac

If so, you can just hook it to da petcock vac line, pump it ta open da petcock,,,   

wait a lil bit,, n' start her right up.. 

[fordmano]

I wouldn't worry about priming the carbs too much, they will fill up fast enough as to not hurt anything.

[longrider]

These ladies don't pull a lot of vacuum until they are running.  When I drain for the winter and the bowls are dry I always pull a vacuum on #6 either with the brake bleeder for a minute or so.  doesn't take much to open it.

[9Ball]

It takes very little vacuum to open the valve.  Just draw a little suction as if you're drinking through a straw, then clamp (or fold) the tubing....this works well and will get the carbs primed.

[salty1]

I wouldn't worry about priming the carbs too much, they will fill up fast enough as to not hurt anything.

+1   Also as 9Ball said, it doesn't take much vacuum to pull open the petcock diaphragm.