I'm hoping next weekend to start the manifold/riser replacement on my 311 Formula. (thanks to Too Old). At the same time I am ditching the "bolt on" silent thunder swim platform exhaust box. I am going to go with new thru hull exhaust tips as the stock ones are way to short for my taste. Question is do I want to go with tips with the "internal" flappers. I don't like the looks of the traditional "Salsbury Flappers" but I've heard the internal ones burn out frequently. Who has what and with what success? Feedback please.
Thanks.......

Yes on the flappers, internal may burn up but may not. The external will keep water out when backing up. They help keep noise down also. I would say external at the least. I have both but the ext are stainless (shotgun) exhaust.

external rubber works good, but doesn't look very good
internal, if metal can rattle a lot

I like the cleaner look of the internal (stainless steel). I had slashcut on the Donzi with SS internal flapper and it never gave me trouble. As for the sound of metal noise, no way if your exhaust is throaty. The flapper really never gets a chance to close while the motor is running.

I had the quick and quiets on mine w/ external flapper.....swapped them out for Rex Marine 90degree angle cuts w/ internal flappers. You can hear the internals a bit at idle but it's not really that bad. I like the sound much better with these.

I'd go with BOTH---but then I've been burned by water ingestion--cost me two engines.

The real problem was mechanic didn't put the 3" riser extensions in exhaust and there wasn't sufficient fall in exhaust line. From my experience make SURE you watch that issue.

Poorsche

Troutly, you do realize we are speaking of exhaust tips here.

Our older no burn flaps are a little noisy at idle particularly with large cams. The new Superflappers however are very quiet and offer much more longevity as well. We have yet to lose a set even on blown motors.

I'd thrown some condoms on her!

Speeking of Flap's, I have Gill 4" thru-hulls with the internal flap.
One is shot and the other one aint pretty. Some one has to make replacements,
any one know who to call?

Thanks,
Uncle Ernie