vacuum ports on int manifold???

i just put carbs on a kz1000 what are the vacuum ports on the manifolds for????

For the carb sync adjustments. This is how with a running engine the carbs are adjusted to equalize the air flow.

First thing to do is check the valve clearances before any tweaking of the carbs. If a valve is on the "tight" side of the clearance,heat from running may have a valve leak compression screwing up trying to sync the carbs.

thanks mfolks