Originally Posted by 10x

Use the Drew Marine Shotgun mufflers. I used them for years and they were fine. Plus, when you want to make some noise, like from open exhaust, I cut a little short piece of plastic hose, like 1/8th" stuff, just as long as the plunger that goes in and out of the spring loaded cylinder.
When you hand open the flapper, the plunger comes out of the cylinder, and it's spring loaded to shut when you let go, or at idle when there's little pressure. While it's open, just measure the length of the little rod sticking out of the cylinder, cut a piece of 1/8th" clear plastic hose, take a razor and cut a slot all the way down one side. That way you can open up the hose, and push it onto the plunger, and the plunger won't go back into the cylinder, thus keeping the flap at the back wide open.

I would do this once we left the dock and exited the harbor. Then I had complete open exhaust. If we came into the harbor late in the evening, I would shut off the engines outside of the harbor, and take off the 4 plastic hoses on the mufflers, and it would be quieter again. :D

If you're interested in that set up, give me a pm, and I'll send you my phone # and I'll explain how it works. You can have the best of both worlds, quiet at the dock, well they're really not THAT quiet, but a little quieter than open headers, :rolleyes: and open exhaust out on the lake while running.

Frank

Originally Posted by SMITHBOY

Sent you a pm, thanks!

Originally Posted by Pantera28-650HP

Here's the new CMI Muffler picture:

Ateco will need your exhaust size and HP.

Originally Posted by Wild Card 09

I´ve run the CMI Sound Eliminators this season on my 525EFI in a 25 Outlaw. They are really good at taking the sound level down and taking the sharpness off the tone at idle. They open up between 2500 and 3000 rpm, as the boat comes on plane, so the really agressive sound cuts in as the acceleration starts. I´ve run the boat with and without and reckon that there´s maybe a loss of 50 rpm if at all. I hit the 5350 rpm revlimiter more readily without them and at over 80 mph gps. I love them. I think the boat sound better with them, at full throttle and under hard acceleration. They look good and are easy to keep clean.
Only one complaint - they rattle at idle - producing a noise that doesn´t sound so good, but disappears once over 1000 rpm. I´m working on that one.