359 with a catalytic muffler/ changed it out

Thanks Mm
Best pictures & explanation I've seen for a muffler mod.

I'll think about it.

My thoughts are :
it was manufactured to meet "x'" specs & the muffler matched (tuned) to a particular saw.
If that's modified much, do you risk exceeding the specs & shortening the life of the saw.
No doubt about thee more power & RPM.
If ran for a while at higher rpm than it was engineered for, will that cause problems.

I'm not saying any of it has amy factual basis or merit, just my thoughts.

Growing up, a few buddies were hot rod / gear heads.
Faster & more power , bigger carb, headers, cranks ... ...
but seemed to be under the hood working a lot on their rods.
I drove a VW Beetle , LOL

I worry that making more power & speed can cause stress on some components,
& over the long haul,
shorten the life of the saw.

Why not just buy the next size up saw ?

My last new saw, 1982 Husqy 61 lasted me 30 years.

Got near $500 in the 359, hard for me to get in there & tweak on it much with the the above
thoughts rattling around between the ears.

Now :
Feel free to shoot holes in my thoughts & logic.
Not gonna hurt a dumb ole hillbillies feelings, comfortable in my skin.
And
I understand you guys who make hot rods, lots of great fun &
I admire the skills & knowledge it takes & the pride felt in doing it well.

 

You won't shorten the life of your 359, as a matter of fact, it will likely increase the life of it. That muffler holds a lot of unnecessary heat in the engine. Letting that heat out is a good thing. Just watch that you get it tuned correctly after opening the muffler.

 

I second what mastermind said. Especially with that factory catalyst in there your retain g a lot of heat right on that cylinder. Allowing it to get the exhaust out faster keeps it cooler as you dont have it bouncing g around as kong in the muffler as well as reducing the back pressure which also decreases temps.

 

Some sound logic.

Got me thinking about who I know that could weld the deflector on.
Your pics are modifying the catalytic one?
(Exit port & deflector on the top , you just leave it alone? )
Haven't looked inside the muffler to see how it's different than the posted picture of the cat one.

Lots of noise level increase ?

Changed the cat muffler out last year

OP:
"Changed the cat muffler on my 359 after the warranty ran out.
http://www.baileysonline.com/Chains...st/Husqvarna/Muffler-Assm-357-359-Non-Epa.axd"

Pictures are of the original catalytic muffler
The one on the saw now is the factory non catalytic, same one that's on the 357xp

Took the screen out of the one on the saw last night.
So have made a few small modification steps already.

 

If you can
Post some step by step pictures.
I'm getting real curious.

 

Your saw has a limited coil in it. You can't rev beyond what it will allow. It will just cut out and start to burble (4 stroke). So you are not going to hurt it at all, in fact, you will only be getting the rpm's it was designed to run at before the almighty EPA got its greasy mitts all over it.
Go forth, mod your muffler and be happy!

by the way, I have over 400 cord through my 359, still running like a banshee!

Ted

 

Most 359s don't have a rev limited coil. Are you sure?

 

mine does. It had the cat muff on it.
Ted

 

I see. What was it limited to?

 

I just went out and checked. Mine has the blue coil, which IIRC, is the limited one, no?

Ted

 

You modify the muffler on your saw ?

How to look to see if I have the rev limited coil ?
You know what RPM is it limited to ?

EPA, am I headed for jail for making good modifications to a saw
LOL

 

Geez, Randy, your the MM, not me! I don't know what it is limited to!

Ted

 

Yep, the blue one is limited. Thing is that the blue coils range from 13,000 - 14,100 rpm though.

 

so, what would I gain if I put the non rev limited one on? That range sounds good to me, no?

Ted

 

No what I mean is that there are several different blue coils. I've got them that limit rpm to 13,000, 13,300 13,600, 13,900, and 14,100.

As long as you can tune the saw properly, I see no reason to change to an unlimited coil.

 

oh okay. When I first came on The other site, everyone said to get rid of the cat muffler and the limited coil right away, of course a muff mod was mandatory and for sure port it or it would never be a good saw!

What I really needed back then was the metal clamp on the boot and the zama carb and I was fine. Put the non cat muff on last fall, and just last week put the Walbro back on after tree monkeys work on it. One day, maybe, I will have it ported when it needs a rebuild? Who knows!

I do not know what the limit is on my coil. For some reason, and I don't know why, but 13,100 seems to stick in my head. Could be wrong, for sure!

Ted

 

Mm
On the last picture, I don't see the top exhaust port, the original factory port.
Did you hammer it flat or is the angle of the picture just not showing it.



can see it here on my muff & the one on the saw.

 

They leave them in place usually so its a dual port for more exhaust flow.

And yes modding a muffler is louder to answer a previous question. My ms659 with the dual port and internal barrel cut out is still pretty loud with muffs on. I turn the radio feature on to drown it out when I dont want to hear it anymore. But I admit I like how it sounds.

 

That is a NOS 359 and the owner wanted it to stay pristine. We removed the top outlet completely so it would never discolor, or melt the top cover.