Nice, first inserts I've seen that are made w/ a jam nut rather than drilling through the exhaust! I'm not about to drill through my jacketed, extremely loud, dry exhaust!

Talk to Graham about sizing for your app. He's great to deal with and can make you anything you need. I've done some dyno testing with them and think BobL on here has as well. They're excellent all around.

Gibson clamp-ons if you really need to quiet it down. Don't get the inserts, you need the big clamp on ones. I have a pair but never use them because I love the sound of the unmuffled 525.

These: http://www.gibsonmarine.com/bullet1.html They work very well and do not rob power.

I dont care what anyone says, nothing is as quiet at idle as Gibson Turn Downs (or any turn downs really), other than captains call. The exhaust is 8" or more underwater at idle, and fully open once on plane, so there is no restriction and zero power loss.

I took mine off because it was TOO quiet at idle for my tastes.

Totally dry, probably not. They do have a rubber seal in them that might burn up with totally dry. I also have dry pipes but bored a 1/4" hole in the inner sleeve towards the end of the pipe. This let's just enough water into the pipe to keep the seal cool. You can see how little water in the video below. The majority of the water still goes out the dedicated dumps!

http://www.youtube.com/watch?v=DiFKbLrRfjs

I have used several sets of GGB's in the past and can't say enough good things about them. You can't go wrong with them.
Eddie

Thanks for the info, but, that was a shot taken at a close friend of mine who used to own a very loud boat. Hence the use of language and emoticon.

I thought it was a two part reply, my mistake!

What an azzhole that guy was!

no worries