Just recently installed CMI ETOPS on a 496 MAG HO. While in neutral exhaust water only comes out the starboard exhuast. I'm told by "others" that this is normal while in neutral. Can't get CMI to answer my emails. Would really appreciate any insight. Thanks!

restrict the side the water is coming out..or you may have a weak impeller.

is the water being shifted to the starboard side only?

That doesnt make sense - how is the exhaust getting cooled on the side water isnt coming out.
It is not correct...

+1 whoever told you it's not suppose to be coming out both sides is feeding you BS.

agree, water can't mysteriously move to just one side with no crossover on the headers... BS on that.

i installed a set on a customer's 277 islander and at idle in neutral i had good water flow through both pipes, definatly check the impeller also check to make sure the collecter tube hoses aren"t pinched off.
port side fit ok starboard on the other hand was a nightmare due to the cool fuel module being in the way
i had this problem while installing them ,had to make my own, so much for a bolt on kit!