I just replaced the factory mufflers on my Baja272 with some simple straight tips with the internal rubber flapper from Hardin. I was shocked at the clanking even with the rubber flappers, and it sounded like the motor was coming apart into empty coffee cans. I put the Salsbury flaps on and that helped a lot, but you can still hear a good deal of clanking through the engine compartment even with the hatch closed.

Is this typical?

I have seen where some of that junk will even trigger you knock sensors.

Yes, it is typical. Yes, it is annoying as hell. No, they won't stop. Yes, they will drive you crazy. Yes, you will think that a connecting rod is about to make a surprise entrance into the cockpit.

They are about the only ones that won't burn out the first weekend. In order to be that tough, they are primarily all SS. Others are mostly rubber, and they don't last. All of that SS makes noise. Personally, I try not to use them if at all possible. If you can run the Salisbury flappers (don't have a slash cut tip) then you don't need the internal ones. You can remove them as you only need one or the other. Most guys that use the internal ones are using slash cut (bologna cut) tips that won't accept a Salisbury flapper.
Eddie

Thanks, Eddie,

I got the straight cut ones so I can use the end flaps. The angle tips look cool, but it's under the molded swim deck anyways. If those are adequate I'll be pulling those internal flaps out. Good Lordy.

Looks like that cruise must of recharged your batteries...lol

I'm a new man. It's amazing what a few days in the sun and some fruity umbrella drinks will do for your attitude.

And lots of lobster.......that's always helps.

Bought my my old cat and started sounding funny, thought I had major issues. ..turns out one flew out the pipe and I was just hearing the odd canker thud of the one side. Cheapest fix in the world! Pull the other side out! Of course my exhaust was way above the water

The external ones are certainly sufficient. Pull the others out and enjoy some quieter boating.

I want to get rid of the rubber flappers and get something more appealing. Thought about just taking them off and leaving them off but my boat sites a bit low in the water.[IMG][/IMG]
this was taken when we where leaving to go to the starting spot for a poker run

just saying currently for the black engine side Mercruiser is recommending both internal and external exhaust flapper. One of the big reasons is the catalyst.

Just as curious - Would have to check to see if that also applies (flappers internal & external) for the 520, 540 and 565 Merc race apps. Not sure about that one currently, heck I forgot to ask that question about Merc's position with those apps as well.