Need help with a muff mod! Can't get a Husqvarna muffler uncrimped.

[ANewSawyer]

So I am working on a muff mod for my Husqvarna 125B in preperation to doing my Husqvarna 435. I need some help though. I can't get the muffler uncrimped with my propane torch. I did an other muffler but have had no success with the Husqvarna. Now what I am thinking about doing is grinding the edge of the crimp off all the way around the muffler. Then getting somebody to weld the two pieces back together. It is possible or am I better to keep trying to uncrimp her?

Thanks in advance.

 

[hills bay performance]

I think those mufflers are seam welded not crimped . If you do get it apart the likelyhood of being able to effectively put it back together with out welding is very slim. Cutting and welding would probably be the easiest. I would see if anyone who more familiar with that model has a way of porting it with out disassembly of the muffler.

 

[spindrift7mm]

Sounds like you just need it alittle hotter, is it getting red ? If not use MAP gas. Ken

 

[spindrift7mm]

Yep I aint familiar with that model.

 

[ANewSawyer]

I think those mufflers are seam welded not crimped . If you do get it apart the likelyhood of being able to effectively put it back together with out welding is very slim. Cutting and welding would probably be the easiest. I would see if anyone who more familiar with that model has a way of porting it with out disassembly of the muffler.

I am mainly doing this for fun. I could do some work now though. Is it possible to tell seam welding just by looking? I can post a pic if need be.

I am trying to find somebody local to weld it but I am not sure if I will.

Sounds like you just need it alittle hotter, is it getting red ? If not use MAP gas. Ken

No, Ken, I am not able to get it red hot. This just a simple propane torch where the torch screws onto a small cylinder. I hold it by that cylinder. Sorry, I am low tech.


This what you are referring to, correct? Edit: The map gas will NOT work with my torch. I will need another torch.
http://www.autozone.com/test-scan-a...ies/worthington-pro-fuel-cylinder/166064_0_0/

 

[hills bay performance]

I think that saw is a stratocharged engine were it injects air into the cylinder along with the fuel . If its the same as a 460 its a bit involved to do a successful mod . I dont know if just doing the muffler is gonna make enough difference to justify it.

 

[ANewSawyer]

Jughead has done done some work on the 435 I think. I may drop him a line. Thanks for the help. I didn't realize my 435 was a strato.

The 125B that I am also working on does not appear to be strato and the muffler is full of cat.

 

[Chris-PA]

I think that saw is a stratocharged engine were it injects air into the cylinder along with the fuel . If its the same as a 460 its a bit involved to do a successful mod . I dont know if just doing the muffler is gonna make enough difference to justify it.

Strato engines respond to muffler mods just fine, it's just that they are usually not as choked up as they do not blow as much raw fuel out the exhaust, and so they don't need cats and such. However sometimes they are restrictive just to reduce noise.

 

[hills bay performance]

Thats good to know might have to try one on my 460

 

[Big_Wood]

the seam is likely brazed as well. i totally lost patience with splitting mufflers so just do what i can without splitting it or buy a hollow AM can to start with if available.

 

[ANewSawyer]

Strato engines respond to muffler mods just fine, it's just that they are usually not as choked up as they do not blow as much raw fuel out the exhaust, and so they don't need cats and such. However sometimes they are restrictive just to reduce noise.

Good to know. I will check the muffler on my 435.

the seam is likely brazed as well. i totally lost patience with splitting mufflers so just do what i can without splitting it or buy a hollow AM can to start with if available.

I don't think I will find a AM muffler for two so small engines. I think in the long run, I will find that a splitting isn't practical. The more I think about it, the less I like it.

 

[Chris-PA]

There are other ways that can work with some muffler designs - I often drill a hole from the outside and use a die grinder to open internal baffles, and then close it with a cover. Here is a muffler for a GZ4000/400 saw:

 

[towingace]

Good to know. I will check the muffler on my 435.



I don't think I will find a AM muffler for two so small engines. I think in the long run, I will find that a splitting isn't practical. The more I think about it, the less I like it.

Don't you just hate it, when a plan doesn't come together?

 

[ANewSawyer]

There are other ways that can work with some muffler designs - I often drill a hole from the outside and use a die grinder to open internal baffles, and then close it with a cover. Here is a muffler for a GZ4000/400 saw:

View attachment 415031
View attachment 415032
View attachment 415033

On the 125B I could probably do this with drill bits and my Dremel. I will want to do that outside! Newb question: What kind of screws did you use and how did you get them to stay in? I think the red stuff is some kind of sealant or adhesive.

Don't you just hate it, when a plan doesn't come together?

I mean, I could still split it by cutting. But I don't think it is going to be easy getting it welded back together. More accurately, finding someone to weld it will be a pain. S'all right.

 

[Chris-PA]

What kind of screws did you use and how did you get them to stay in? I think the red stuff is some kind of sealant or adhesive.

On that one I used some stainless steel square drive sheet metal screws we use at work. The cover is a sheet of low grade stainless steel from the cover of an old microwave oven. The sealant is Permatex Ultra Copper. I've used Ultra black too.

 

[spindrift7mm]

I am mainly doing this for fun. I could do some work now though. Is it possible to tell seam welding just by looking? I can post a pic if need be.

I am trying to find somebody local to weld it but I am not sure if I will.




No, Ken, I am not able to get it red hot. This just a simple propane torch where the torch screws onto a small cylinder. I hold it by that cylinder. Sorry, I am low tech.


This what you are referring to, correct? Edit: The map gas will NOT work with my torch. I will need another torch.
http://www.autozone.com/test-scan-a...ies/worthington-pro-fuel-cylinder/166064_0_0/

Looks like your getting good info, I'm not familiar with that model. Yes map gas is kinda the next step in torches/heat. I found it when having trouble soldering a leaking water pipe with a dibble running through which drew all the heat. A plumber friend suggested the change to map and I've used it ever since. The extra heat makes most work faster and smoother. Higher cost is offset by less gas used for the same job. Good addition to your tool box. Ken

 

[KenJax Tree]

I did the 125B at work and i didn't split the muffler, i just used a drill bit and drilled all the crap out....pics tomorrow.[emoji6]

 

[lasmacgod]

On my 125B and 327ldx, I took a bench grinder to the outside edge of the seam, pulled it apart, cleaned up the sharp edges, opened up the outlets within the limits of the deflectors, reassembled (minus the cat), and brazed it all back together. It's not the prettiest, as I am a bit out of practice with brazing, but the mufflers on both are covered and not readily visible. Be careful when brazing or welding these mufflers as they are galvanized. The 125B has wonderful throttle response now, and restarts much easier. The 327ldx would get hot when working it hard with the edger attachment. It would not stay running unless it was at full throttle, and would not restart easily unless it cooled off for several minutes. With the cat gone, it runs flawlessly and restarts easily.

Both are much louder as well, but sound great.

 

[rmh3481]

Remember all muffler mods require more fuel, open the H jet.

 

[shorthunter]

I am not familiar with the 125 but you may consider a fish gill opening. Simply cut a portion of the muffler and open it up with a screwdriver. I use a die grinder with a cutoff wheel to cut my opening, then pry it open with a flathead screwdriver. The best thing about this style of opening is that you can fine tune the backpressure by closing the fish gill back down a bit or by opening it up a little more