Just replace the exhaust flappers or shutters on my merc 4.3 Bravo 111 Drive now I notice a banging sound in the exhaust Y pipes that comes on now and then Is this normal.

Hawaii where the Sun always Shine

INTERNAL FLAPPERS???

yes!!!!!!!!!!

Annoying isnt it!!!

rchevelle71 nailed it...internal flappers. drove me nuts when i first installed mine...now I'm used to it

I hated that noise so damn much, I pulled em off, and put on a set of Corsa muffler tips with external flappers. Whenever it was idling, sounded like my Damn motor was coming apart!!!! And of course we have a lot of idle zones on the ICW down here(damn sea cows!!!), so I wanted to quiet it down a little with Mufflers anyway. Still plenty loud when I open it up, but no more headaches from idling.

Yeah tell me about it.....on my first startup with the tips on I was back there with my ear to the engine listening thinking the engine was fixing to grenade.....the I realized it was the internal flappers haha.