The op has already stated that he will be fitting hoses to the nipples. Fine and dandy. However, I disagree with you. The vents are not only to allow fuel to flow into the bowls, but also to exert atmospheric pressure on the fuel in the bowls. The differential between this and the venturi pressure is what forces the fuel through the passageways, into the carburetor throat. If enough wind blows across the ends of the nipples, yes, a vacuum can be induced. In their isolated position between the carburetors, though, I don't see how enough airflow will develop to affect their operation, never mind "suck the fuel" out of the float bowls. I had the vent nippple turned down on an ex500 for years, no problems, and it's much more out in the open than on the Connie. In fact, the stock location of the clear vent tube on the ex500 has been known to cause this exact problem under certain conditions, so among owners of that particular bike it's accepted practice to remove the hose and turn the nipple down. I don't see any such problem with the Connie, though, since the hoses are tucked away behind the side covers.
well, I guess we can agree to disagree.
this ain't an EX500. I have no clue about what works or doesn't on them.
I think I have seen every permutation of what someone deemed as "ok" as far as carbs on a ZG goes, over the last 13 years... and have fixed the ones, that people thought were "ok"/ but they had issues....
short of Bubba Steve, I don't think anyone around knows more about ZG/Kehein combo issues, and even Steve will sit and talk with me about mysteries on these carbs. We just live them. Plain and simple.
with that said, and not trying to be a smartazz, I'll just ask you to go out, pull those hoses off your ZG, turn the fittings as close as you can to upside down, and ride it.
Then come back, after going thru 2 tanks of fuel, (approx 500 miles) and tell me it ran no different, or even better...than it did with the hoses attached, and correctly routed... oh, and make sure out of that 500 miles, at least 100 of them was driven on a freeway at 70mph, drinking from a firehose in a torrential down pour.
Thanks for your input.
the hoses need to be in place.
and routed up and behind the side covers.
and yes, when in position they are located up high under the side panels, but if the hoses are removed, the side covers act as a funnel' and introduce turbulent air all around the carbs, and rear of the head, that is why when a carb clamp is loose, it it VERY evident there is a problem.. lots of air in there, swirling...
telling someone to do what you "think" is ok, ain't gonna cut it.
sorry.