New to (muffler) mods

[NormK]

New to saw mods. Would any of you guys have any links to any good muffler mod videos? I have 3 saws and I am wanting to see if I can get at least a modest boost from a muffler mod. I have a 40cc Craftsman, a Husky 350 and a Jonsered 2255. Thanks!

 

[cuinrearview]

Search "Matthew Olson" on youtube for a bunch of vids on your 350

 

[NormK]

Search "Matthew Olson" on youtube for a bunch of vids on your 350

I belive I have watched all of his videos on the 350 along with Walt at afleetcommand, but I don't recall seeing any how-to vids on muffler mods. I will look again. Thanks

 

[cuinrearview]

An easy way to do a 350 is just to enlarge the factory opening under the deflector. Take a big flat head screwdriver and lift up the deflector. Then you can get a burr or drill in there to open it up. Just make sure to keep it under the deflector or you'll burn a hole in the top cover. When finished, bend the deflector back down with pliers or tap it back down with a hammer.

 

[Brent Nowell]

I personally use steel tubing for a pipe and use a hole saw for the hole.
The mufflers on husky’s stock are pretty thick gauge and hold up to a hole saw fairly well. However if you want to do it a cleaner way get a diamond hole saw instead and take it slow. Less aggressive and no chance that it will oscillate.
Pick a hole saw size that is the same size or just smaller than the steel pipe OD you wish to use. If it happens to be smaller then slowly dremel the circumference until your pipe fits snug.
Brass with bronze flux coated rods, you will need oxy acetylene or a B tank in order to get it hot enough. Cherry red and it will melt the bronze rod. practice on old steel stock of similar gauge until you get the hang of it.

maybe your done the best way to remove the left over flux is with a wire drill brush wheel, a stiff one will make short work of the glazing.

finally sand with whatever you wish to make it look pretty, or go straight to the degreased (brake clean and paper towel.

paint with engine heat paint of the Desired colour, choose one that is good for 450-700 degrees that doesn’t require a primer. couple coats and let dry for 12-24 hours.

put her in the vice and apply a heat gun right to the flange end and start pumping hot air through. When it smokes it’s starting to cure, continue for a couple more minutes then stop.

you will end up with a muffler that looks pretty decent with a nice round much larger port than stock that will be as strong as the muffler itself. The paint will hold up to the abuse that a saw receives.

 

[NormK]

I personally use steel tubing for a pipe and use a hole saw for the hole.
The mufflers on husky’s stock are pretty thick gauge and hold up to a hole saw fairly well. However if you want to do it a cleaner way get a diamond hole saw instead and take it slow. Less aggressive and no chance that it will oscillate.
Pick a hole saw size that is the same size or just smaller than the steel pipe OD you wish to use. If it happens to be smaller then slowly dremel the circumference until your pipe fits snug.
Brass with bronze flux coated rods, you will need oxy acetylene or a B tank in order to get it hot enough. Cherry red and it will melt the bronze rod. practice on old steel stock of similar gauge until you get the hang of it.

maybe your done the best way to remove the left over flux is with a wire drill brush wheel, a stiff one will make short work of the glazing.

finally sand with whatever you wish to make it look pretty, or go straight to the degreased (brake clean and paper towel.

paint with engine heat paint of the Desired colour, choose one that is good for 450-700 degrees that doesn’t require a primer. couple coats and let dry for 12-24 hours.

put her in the vice and apply a heat gun right to the flange end and start pumping hot air through. When it smokes it’s starting to cure, continue for a couple more minutes then stop.

you will end up with a muffler that looks pretty decent with a nice round much larger port than stock that will be as strong as the muffler itself. The paint will hold up to the abuse that a saw receives.

Are the mufflers just a hollow "box" with some slits under a cover or something? I have not seen the inside yet. I ordered a kit for my 350 that comes with a muffler and a bracket like goes on a 346XP to try and keep the muffler from coming loose, though to date the muffler has never been loose.

 

[Deleted member 149229]

Are the mufflers just a hollow "box" with some slits under a cover or something?

Depends on each saw, some are cans, some have baffles and some have catalytic converters.

 

[NormK]

Catalytic converters?!?!?! I don't think I have one of those saws...

Depends on each saw, some are cans, some have baffles and some have catalytic converters.

 

[Brent Nowell]

Husky products indicate a cat with a green fuel cap. These are actually the engines you want to look for in my opinion. It denotes a non strato design which is easier to port and generally easier to tune especially when your dealing with low end Chinese carbs.

to remove the cat there’s no easy way, get some snips or a grinder and cut the perimiter lip off and it should come apart. Sometimes they are also held together with the bolt sleeves, but at that point it’s easy to pry apart.
These muffs also have a baffle system which is incredibly restrictive and requires even more work to remove.
I had a craftsman saw I bought 6 months ago that had one utilizing a red max engine non strato. The end gains for the work was well worth it.

 

[svk]

Depends on the construction of the muffler, and your tools/abilities.

I do not have the stuff to braize/weld so I do "swiss cheese" mufflers on my homeowner grade saws and send out my pro saw mufflers (or those with cats) to one of a couple different members on here to do the work.

See post 78. This significantly woke up the saw over stock.
https://www.arboristsite.com/community/threads/husqvarna-130-first-look.336558/page-4

 

[cuinrearview]

Catalytic converters?!?!?! I don't think I have one of those saws...

 

[Brent Nowell]

On another note I did this to my cat 325

View attachment 793394

That looks like a lot less work to remove than the craftsman I worked on!
Those are makita/dolmar mufflers yes?

 

[cuinrearview]

Those are makita/dolmar mufflers yes?

Indeed. You can drill/punch the cat out through the inlet, but you still have the restriction from the plate in there. I like to open the can and drill/cut the spot welds for the entire plate. Then what you wind up with is a completely open can and the stock opening on the outer shell is actually very healthy. I like modding the later mufflers better than the older silver 5100s cans that a lot of people prefer.

 

[NormK]

Indeed. You can drill/punch the cat out through the inlet, but you still have the restriction from the plate in there. I like to open the can and drill/cut the spot welds for the entire plate. Then what you wind up with is a completely open can and the stock opening on the outer shell is actually very healthy. I like modding the later mufflers better than the older silver 5100s cans that a lot of people prefer.

So, basically the idea is to take the muffler apart, remove any baffles or internal "stuff" and then put a piece of 3/4" pipe in a hole in the muffler at an angle so it blows toward the top of the chain and then weld it in and re-install the muffler. I assume that after the exhaust is opened up the carb will need to be adjusted to allow more fuel.

 

[cuinrearview]

So, basically the idea is to take the muffler apart, remove any baffles or internal "stuff" and then put a piece of 3/4" pipe in a hole in the muffler at an angle so it blows toward the top of the chain and then weld it in and re-install the muffler. I assume that after the exhaust is opened up the carb will need to be adjusted to allow more fuel.

Every muffler design mods differently

 

[Brent Nowell]

So, basically the idea is to take the muffler apart, remove any baffles or internal "stuff" and then put a piece of 3/4" pipe in a hole in the muffler at an angle so it blows toward the top of the chain and then weld it in and re-install the muffler. I assume that after the exhaust is opened up the carb will need to be adjusted to allow more fuel.

The position of your pipe and angle can have an impact on the saws performance. When I say this I mean that if you position the pipe poorly you will be shooting exhaust dead on to wood when you are bucking straight up against logs. This causes a restriction and adds to heat to the engine not a good idea. The stock port usually comes out on top of the muffler but about an inch away from the front of the muffler slightly shooting up. This allows for exhaust to breath when your right up against a log.
I’ve found the corner is a good spot to shoot the pipe away from.

 

[henry r]

Straight forward facing exhausts also present a fire risk + the sound can bounce off the timber.

If you are pointing the exhaust out the rhs i would aim it over not at the chain. I can't say for sure that the heat of the exhaust would have a negative effect on the chain/chain oil but if the exhaust misses the chain it is one less thing to worry about.

If you cut (well buck) mainly right handed, aiming the exhaust out the rhs also puts it at the furthest point from your ears and aims the noise away from them.

 

[NormK]

The position of your pipe and angle can have an impact on the saws performance. When I say this I mean that if you position the pipe poorly you will be shooting exhaust dead on to wood when you are bucking straight up against logs. This causes a restriction and adds to heat to the engine not a good idea. The stock port usually comes out on top of the muffler but about an inch away from the front of the muffler slightly shooting up. This allows for exhaust to breath when your right up against a log.
I’ve found the corner is a good spot to shoot the pipe away from.

Okay, my replacement muffler, bracket, gasket and screws just came in. The new muffler is hollow. Nothing but an empty box with the tubes inside to prevent the screws from crushing it. Out of curiosity, I took the muffler off of my 350 and saw that it is the same way. Hollow box. Took a look at my piston through the exhaust port. Nary a mark on it except for a little from when the piston was turned. I guess that is an indication that this saw has very little use on it. Anyway, I am gonna mod the new muffler to look much like the one in the photo you posted. Must it be round? Can I use an oval shaped "pipe"? How big is too big? How small is too small?
Thanks!