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Muffler Mod

Post in 'The Gear' started by mikefrommaine, Sep 4, 2013.

  1. Here's how I did my latest muffler mod.

    I have been using the husky deflectors to add a second port. But they are expensive,and I'm cheap. I used a piece of 1/2" aluminum electrical conduit as the deflector.

    I saw mastermind and others using silver solder instead of brazing but I had an oa torch and have been looking for an excuse to learn brazing. The idea of a pipe outlet in front of the cat was 'borrowed' from mastermind :). Sure beats trying to cut or drill out the cat.

    .. So here goes, questions, comments and concerns?

    I used sketchup to measure the area of the exhaust port. I also made a template of the deflector and used that info to make a template the exact size and shape I wanted.

    [​IMG]
    [​IMG]

    Here's the template, exactly .47 square inches, which when added to the existing outlet gives me a total of 85% of the exhaust port.

    [​IMG]
    Last edited by a moderator: Sep 4, 2013

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  2. You can see how choked up this muffler is
    [​IMG]
  3. My first attempt at brazing
    [​IMG]
    [​IMG]
    [​IMG]
    ScotO and smokinj like this.
  4. A little paint does wonders
    [​IMG]
    smokinj likes this.
  5. On the saw
    [​IMG]

    [​IMG]
    clemsonfor, ScotO and MasterMech like this.
  6. Michael Golden

    Michael Golden Member

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    May 17, 2012
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    Cambridge, Ohio
    Looks stock! Nice job.......
  7. StihlHead

    StihlHead Guest

    I do shark gill slits and rivet on a Husky deflector over a screen (need that here for fire season). No torch needed.

    But nice job! Wojo wants $125 for mufflers re-welded like that on Ebay.
  8. That is a downside to this style muffler mod... Next time I'm going to extend the pipe a little and pick up a pipe spark arrestor like on the stihl cut off saws.

    [​IMG]

  9. I hadn't seen that:

    http://www.ebay.com/itm/Custom-Stih...736?pt=LH_DefaultDomain_0&hash=item35cb50d048
    Up for auction one 361 custom dual port muffler. What is very unique about this is that all the steel that is added to the cover is stainless steel. I made this myself and it is all welded. A very complicated welding process where steel wire is introduced to stainless steel pipe.



    So complicated it took me, who has never welded anything, ten minutes to figure out how to get a pipe to stick to the muffler LOL. Total cost, about 35 cents.
    Last edited by a moderator: Sep 4, 2013
    ScotO likes this.
  10. MasterMech

    MasterMech Guest

    Sounds like a MIG gun or TIG, or Gas welding to me. TIG would do a real nice job on the muffler for sure. Not that complicated but the equipment is very expensive compared to brazing.

    What kind of torch did you use Mike?
  11. clemsonfor

    clemsonfor Minister of Fire

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    2,273
    Loc:
    Greenwood county, SC
    Nice
  12. DexterDay

    DexterDay Guest

    I have a "round" cone type screen if you wanted one? Took it out of a small 2 stroke Genny.

    Nice job though. Is that on the 254xp? Or 359?

    I have a couple I'd pay for you to port? With paint, that's a fine looking job. In my opinion.

    Oh, and I need no Screen. 99.9% of all my cutting is on my property now. ;)

    Again, nice job....
  13. NortheastAl

    NortheastAl Minister of Fire

    Joined:
    Dec 30, 2012
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    676
    Loc:
    Putnam, NY
    Nice clean work on that mod.
  14. I've got a harris Oxy/Acetylene port a torch. Picked up cheap on CL a few years ago. I picked up a #0 welding tip for it; probably would have been better off with a #1.

    [​IMG]
    Last edited by a moderator: Sep 5, 2013
    ScotO, MasterMech and DexterDay like this.
  15. It's on a 359. I'd stick a pipe on the side of a muffler for you but the cost of shipping both ways it might not be worth it? Silver solder seems to be popular over on AS and all you need is regular propane or MAPP torch.
    Last edited by a moderator: Sep 5, 2013
  16. smokinj

    smokinj Minister of Fire

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    Nice work and good touch on the SS.
  17. clemsonfor

    clemsonfor Minister of Fire

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    Heck u van put it in a padded envelope for what $8 each way?
  18. Tinder

    Tinder New Member

    Joined:
    Jan 12, 2012
    Messages:
    37
    Loc:
    Howell, MI
    While cutting that portion out of the muffler makes sense, why choke it using the 1/2" EMT? Assuming 1/2" is the ID, 3.1459 * (.25")^2 = ~ 0.1966"^2.
  19. I was wondering if anyone would catch that ;em

    I had been planning to use an old broom handle I had. But at the last minute I chickened out because it is very thin wall and I was worried I'd burn through it. I guess I'm not very good at mental math and never double checked the area of a 1/2" pipe

    Oh well I'm going see about make the original port a little bigger or cut off the pipe and use a bigger one.

    This one looks better anyways

    [​IMG]
    Last edited by a moderator: Sep 6, 2013
    DexterDay likes this.
  20. The enemy of good enough is perfection :confused:

    I had the new piece all done and should have stopped but wanted to make it flow into the muffler a little better... Ended up overheating a section and all the filler flowed out leaving a big gap !!! . In my attempt to fix it I burned through the pipe<>

    Ended getting it all filled in and was able to fill the hole, but its definitely not easy to fill gaps when brazing a thin wall pipe to the muffler. Definitely easier to do it right the first time.

    Here it is almost ready for paint.[​IMG]

    [​IMG]
    Last edited by a moderator: Sep 6, 2013
  21. The magic of flat black paint :rolleyes:
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    [​IMG]
  22. This is the first time I actually calculated the optimum exhaust size. In the past I drilled a couple holes and covered it with a deflector... Hadn't realized how big the outlet really needs to be. This pipe is about 70% of the exhaust port. Can't wait to try it out.

    [​IMG]
  23. infinitymike

    infinitymike Minister of Fire

    Joined:
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    Loc:
    Long Island, NY
    Pretty cool mike.
    Like they say " paint will make it what it ain't "

    Did you try it out yet? What about re-tuning it.

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