uneven feul flow from petcock outlets

[plankspanker]

Hi everyone. After 3 years of restoration on my 1964 CB77 I am very close to kicking her over and am trying to ensure that all is in order before doing so.
In attempting to check the fuel flow to the carbs, I thought I'd run a test using mineral spirits to 1) flush out any small particulates and 2) avoid gasoline since I am working in my basement!
I put some of this solvent in the tank to a level that allows only the reserve position to dispense (level not high enough to allow "ON" position to flow). Both fuel lines are simply emptying into a container (not attached to carb inlets) so that I could observe the flow.
When I turn the tap to "RES", fuel only flows from ONE LINE. If I shut it OFF and the turn it ON again, fuel now flows only from the other line. I can get the flow to alternate in this way every time I turn the tap on and off and on again.
Does this make sense to anyone? Does this demonstrate 1) that the "fuel' is flowing properly or 2) anything?
If not, can anyone suggest a better way of testing flow without hooking up the lines to the carbs (if possible)?
Thanks!

Scott

[mike in idaho]

It's OK, the gas(or solvent) will always flow out the hole with less resistance. Cover up that hole and it will flow out of the other one.

[plankspanker]

Thanks Mike. Should I assume, then, that when the lines are attached and the bowls are filled that there will be equal resistance between the two - resulting in either 1) equal continuous flow to both carbs or 2) flow to either carb when it is needed?

[davebern]

That's correct. The required flow will never be as much as an open petcock, so both carbs will get plenty of fuel when the lines are connected.