Muffler mod 441cm

[josh1981]

I want to muffler mod my 441cm tronic. Just enlarge the opening on muffler.whats the best way to do this? What tools do I need? I assume the computer will compensate for it correct?

Thanks

 

[StihlyinEly]

I want to muffler mod my 441cm tronic. Just enlarge the opening on muffler.whats the best way to do this? What tools do I need? I assume the computer will compensate for it correct?

Thanks

In the 441CM bologna thread, someone said they muff modded their 441CM and the autotune compensated for it. Since I may pick up a 441CM myself pretty quick, I'm interested in the replies to this thread as well. I'd really like to see what muff mods have been done on this saw.

 

[Officer's Match]

Nothing complicated - just enlarge the hole.

 

[josh1981]

How much power gain can I expect what tool do I use to enlarge the hole...

 

[Stihlman441]

I have done afew of these and have found a nice increase by just doing a muff modd.
There is two ways to go depends on if you wont the spark screen or not.
1 If you do enlarge the hole as much as possible.
2 If you dont care about spark screen,take it out enlarge hole and grind away the track the spark screen sits in.
3 Or then add another slot under as in pic.

I use and air grinder but a Dremmal would do the same thing,the tool i use is a 1/4 dia carbide ball and then a die grinder with a small stone in it to take the burrs off.Being stainless it a bit on the tough side to work with.
The slot under i have made a fixture to hold the muff and machine the slot with a carbide end mill in a milling machine.

Stock

Modd 3

 

[Stihlman441]

After you do any muff modd its a good idear to do the re calibrate set up as bellow.

To recalibrate system (do arfter muff modd)

Remove bar and chain

Put clutch cover back on.

Hold down lever (with palm of hand on top of rear handle)

Press throttle slightly

Push all the way down control lever to choke positoin (use your thumb)

Pull starter cord untill it starts

DO NOT MOVE control lever

Let run for min 60 seconds

Move control lever to stop positoin

It will run rough,smoke,fart and carry on this is normal.

Make afew long steady cuts and all sould be good.:msp_smile:

 

[Stihlman441]

Saw is stock on second tank of fuel,top wood is Pine bottom is Sugargum.

[video=youtube;bKiNyhBS0OE]http://www.youtube.com/watch?v=bKiNyhBS0OE[/video]

 

[Stihlman441]

Stock with muff modd 3 same bar and chain.

[video=youtube;exwpA0mjccY]http://www.youtube.com/watch?v=exwpA0mjccY[/video]

 

[John_DeereGreen]

I pulled the screen out of mine, and enlarged that hole, then drilled 2 new 1/2 inch holes below it. Do the recalibrate and it'll be a very good running saw.

I've got a 372 Husky that's been worked over by a reputable builder on here, and I would put my 441 up against it and expect an even tie. The only big advantage the Husky has is that it rapps up much quicker still.

 

[Stihlman441]

Plug from 441C after muff modd and about 8 tanks of fuel.(95 Oct, Mobil 1 2T @ 40:1)

 

[josh1981]

Is it ok to enlarge behind screen and put that back in and drill a few holes under it? Will a regular drill bit work?

 

[Stihlman441]

If your going to have holes under with no screen then there's no point having the screen in the top port.When drilling stainless dont go to fast in speed and a bit of coolant or oil will help.

 

[porsche965]

Josh,

Why not a full port job? I've heard they come out really good .

 

[josh1981]

Is it ok to run without spark screen?

 

[Anthony_Va.]

Is it ok to run without spark screen?

It's against the law in most logging enviornments, but it will not hurt your saw a bit. You would probably gain a little by not using one. The are put in place to prevent fires from sparks but I don't see it starting any fire that you couldnt stop out with your foot

 

[TK]

I pulled the screen out of mine, and enlarged that hole, then drilled 2 new 1/2 inch holes below it. Do the recalibrate and it'll be a very good running saw.

I've got a 372 Husky that's been worked over by a reputable builder on here, and I would put my 441 up against it and expect an even tie. The only big advantage the Husky has is that it rapps up much quicker still.

You'd put a MM'd 441 up against a quality ported 372?

 

[blsnelling]

You'd put a MM'd 441 up against a quality ported 372?

And lose BIG TIME!

 

[Anthony_Va.]

I'd take that race. :msp_biggrin:

 

[blsnelling]

I'd take that race. :msp_biggrin:

For pinks? Count me in. He can even port his 441!

 

[2dogs]

For pinks? Count me in. He can even port his 441!

Brad in general terms do the stock Huskies run hotter and faster than Stihl saws? Is it the same with ported saws? (I'm not looking to run this thread off the rails I'm just curious. I own both brands and I'm happy with both.)