# Muffler Mod



## mikefrommaine (Sep 4, 2013)

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.








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.


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## mikefrommaine (Sep 4, 2013)




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## mikefrommaine (Sep 4, 2013)

You can see how choked up this muffler is


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## mikefrommaine (Sep 4, 2013)




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## mikefrommaine (Sep 4, 2013)

My first attempt at brazing


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## mikefrommaine (Sep 4, 2013)

A little paint does wonders


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## mikefrommaine (Sep 4, 2013)

On the saw


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## Michael Golden (Sep 4, 2013)

Looks stock! Nice job.......


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## StihlHead (Sep 4, 2013)

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.


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## mikefrommaine (Sep 4, 2013)

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.


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## mikefrommaine (Sep 4, 2013)

StihlHead said:


> Wojo wants $125 for mufflers re-welded like that on Ebay.




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.


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## MasterMech (Sep 4, 2013)

mikefrommaine said:


> ]very complicated welding process where steel wire is introduced to stainless steel pipe.



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?


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## clemsonfor (Sep 4, 2013)

Nice


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## DexterDay (Sep 4, 2013)

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....


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## NortheastAl (Sep 4, 2013)

Nice clean work on that mod.


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## mikefrommaine (Sep 5, 2013)

MasterMech said:


> What kind of torch did you use Mike?


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.


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## mikefrommaine (Sep 5, 2013)

DexterDay said:


> 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?
> 
> ...


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.


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## smokinj (Sep 5, 2013)

Nice work and good touch on the SS.


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## clemsonfor (Sep 5, 2013)

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


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## Tinder (Sep 6, 2013)

> 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.


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.


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## mikefrommaine (Sep 6, 2013)

Tinder said:


> 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.


I was wondering if anyone would catch that 

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


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## mikefrommaine (Sep 6, 2013)

*The enemy of good enough is perfection 
*
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.


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## mikefrommaine (Sep 6, 2013)

The magic of flat black paint


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## mikefrommaine (Sep 6, 2013)

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.


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## infinitymike (Sep 6, 2013)

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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## mikefrommaine (Sep 6, 2013)

It's a full rebuild... Haven't had a chance to run it yet.  Started it up after the first muffler mod -- needed to open the low end a bit to get it to idle. Just got the bar today so hopefully I can get some time this weekend try it out.  I did a little grinding on the cylinder (this saw was a pure cad purchase). I hope to embarrass my buddies stock 357xp.


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## infinitymike (Sep 6, 2013)

Hey, no hard feelings with that song last week 
I know I won't be the next American idol, but ya gotta say  it was pretty darn funny.

I want to mod my Sthil.
I really like the way that looks.
I can borrow a small mig welder.


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## MasterMech (Sep 6, 2013)

infinitymike said:


> Hey, no hard feelings with that song last week
> I know I won't be the next American idol, but ya gotta say  it was pretty darn funny.
> 
> I want to mod my Sthil.
> ...


Careful with that MIG Mike.  They can leave spatter partially stuck inside the muffler (if you weld it on the inside) that could come loose later and wind up inside the cylinder.  Braze or TIG is preferred here.


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## mikefrommaine (Sep 6, 2013)

infinitymike said:


> Hey, no hard feelings with that song last week
> I know I won't be the next American idol, but ya gotta say  it was pretty darn funny.
> 
> I want to mod my Sthil.
> ...


No problem, all in good fun.


What stihl do you have? A lot of them can be opened without the need for welding or deflectors.


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## infinitymike (Sep 6, 2013)

MasterMech said:


> Careful with that MIG Mike.  They can leave spatter partially stuck inside the muffler (if you weld it on the inside) that could come loose later and wind up inside the cylinder.  Braze or TIG is preferred here.


Good to know. Thanks.


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## infinitymike (Sep 6, 2013)

mikefrommaine said:


> No problem, all in good fun.
> 
> 
> What stihl do you have? A lot of them can be opened without the need for welding or deflectors.



Ms311


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## mikefrommaine (Sep 7, 2013)

I think the 311 is pretty much like the 361 muffler.  You can weld a pipe or use a husky screw on deflector.


http://www.arboristsite.com/chainsaw/63926.htm

Definitely worth doing


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## ScotO (Sep 8, 2013)

Was the pipe you brazed onto the muffler stainless steel or aluminum conduit?  The first post said aluminum, I was wondering how you got that to stick to steel with brass brazing rod......

Welding stainless steel to steel isn't complicated at all, with a mig or tig, IMO.   I've done it a lot over the years.
I'll be doing some "dual exhaust" soon on the 051, the 372XP, and the MS046 (which is also gettin' a big bore kit this winter).

Nice job Mike!


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## mikefrommaine (Sep 8, 2013)

The first pipe was a piece of electrical emt conduit... I was thinking it was aluminum (I even had it in my aluminum scrap pile) must not be since the bronze stuck to it.  Shows what I know about brazing and gas welding 


I had an a hour this afternoon to play with the saw. Spent the first 45 minutes trying to tune the saw.  I would think I had it but I just couldn't get it to idle right.  It would run fine and accelerate great and then all of I sudden it would die if I let the saw idle for more than 10 seconds or so.  I swapped out the carb with another one and the saw started  on the third pull, idles well and sounds great.

It has a brand new piston and rings but it is already noticeably stronger the my ms361. Pulls a 20" 3/8" chain like a saw should. I was trying to take it easy while it breaks in, but you can really lean on it with chain buried.


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