A couple muffler mod questions

[StoneyMeadowMaple]

I am getting a 372xp soon, I see a lot of pipes and big bulky mufflers that look like a recipe for broken cylinders, some that come out the front, what I don't see much of is enlarged factory openings, why? Surely there would be some gains? Does the deflector negate the benefit? I wouldn’t mind a little more breathing ability, but I would rather not get exotic with a muffler mod. Any suggestions?

 

[thompsoncustom]

removing any baffle inside and enlarging the opening works just fine you don't have to do anything fancy if you don't want to that parts more for looks than anything else. The part that matters is the size of your exhaust port and the exhaust opening.

 

[singinwoodwackr]

I am getting a 372xp soon, I see a lot of pipes and big bulky mufflers that look like a recipe for broken cylinders, some that come out the front, what I don't see much of is enlarged factory openings, why? Surely there would be some gains? Does the deflector negate the benefit? I wouldn’t mind a little more breathing ability, but I would rather not get exotic with a muffler mod. Any suggestions?

the stock 372 can be opened up by bending the top flap up to get better access to the little hole inside. Then, grind out a rectangle about 80% of the volume of the cylinder side port with a Dremel or or other small hand held.
Another way I have done these is to leave that alone and add a 2nd port to the front left side facing at about 45*. drill a 1/2-5/8" hole and weld on a 3/4" section of pipe cut at an angle. I'll find some pics later...

 

[StoneyMeadowMaple]

Should I still be able to adjust the carb within the range of the limiters? Or will they have to go?

 

[Marley5]

I prefer a clean muf mod, no butchering here.
Like to disassemble the muffler, remove baffle and drill out " clean " , return baffle for structural integrity, open up exhaust port 70 - 80 % and open up deflector.

Every saw I own has a muf mod and required a Re-tune and limiters removed.
In my case it's usually the low jett that needed richened up beyond what the limiter allowed.

 

[StoneyMeadowMaple]

I prefer a clean muf mod, no butchering here.
Like to disassemble the muffler, remove baffle and drill out " clean " , return baffle for structural integrity, open up exhaust port 70 - 80 % and open up deflector.

Every saw I own has a muf mod and required a Re-tune and limiters removed.
In my case it's usually the low jett that needed richened up beyond what the limiter allowed.View attachment 1237536View attachment 1237537View attachment 1237539

Do you have a picture of a completed muffler?

 

[Mad Professor]

I prefer a clean muf mod, no butchering here.
Like to disassemble the muffler, remove baffle and drill out " clean " , return baffle for structural integrity, open up exhaust port 70 - 80 % and open up deflector.

Every saw I own has a muf mod and required a Re-tune and limiters removed.
In my case it's usually the low jett that needed richened up beyond what the limiter allowed.View attachment 1237536View attachment 1237537View attachment 1237539

I've done similar modifications to my 038 Stihls. In those cases no need to remove the baffle from the inner case to drill it out. The inner case gets matched to the cleaned up ex port outlet too. The dual port outlets get enlarged as much as possible while still retaining both spark scree.

I love my old Stihls, no limiter caps and fully tunable carbs.

 

[Marley5]

Do you have a picture of a completed muffler?

Here's a couple, Stihl and an Echo.
On the Echo I removed the restrictor tube from behind the deflector plate as well.
On the Stihl I heated the crimp with torch to open.

 

[RedneckChainsawRepair]

372 should be hollow can.

I did simple no cost out the front with screen and some others like putting pipe. Some deflectors.

Ones I seen coming in.

 

[JimR]

Should I still be able to adjust the carb within the range of the limiters? Or will they have to go?

Remove the limiters.