Custom Built PWC Muffler Help

Discussion in 'DIY Marinizing' started by PHecksel, May 13, 2007.

  1. PHecksel
    Joined: May 2007
    Posts: 1
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    Location: SE MI

    PHecksel New Member

    Ever wonder what happens to a bunch of unburned gas and air in a confined space...and then ignited?

    Managed to do some significant damage to the stock muffler on an old MasterCraft WetJet PWC. Ears are still ringing from that one.

    The stock design was literally a straight pipe in, and a straight pipe out the back 90 deg to the inlet pipe. One of my complaints on this old sled was how loud it is. I hate loud watercraft!

    The cost of a replacement muffler box is significant enough, I want to repair this and possible knock down the noise at the same time.

    The old inlet pipe appears to be schedule 30 PVC, and about five inches long in a 9" square box. The box itself, appears to be mostly intact, but the inlet pipe is history. Can I put in some schedule 40 PVC, the entire length of the box, cap the end, and drill several holes through the pipe, maybe doubling the outlet area of the original pipe? My thought is now I'm forcing the exhaust gases to make several turns before exiting. Not real concerned about back pressure, this isn't exactly a HP sled.
  2. gonzo
    Joined: Aug 2002
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    Location: Milwaukee, WI

    gonzo Senior Member

    Sounds like it would work. Make sure the total area of the holes is at least the same as the pipe.
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