MS661C Muffler Mod Testing

[blsnelling]

This is my personal saw. I'd love to test in larger wood, but this is the largest I have. So, I installed an 8-pin rim and a 20" bar. It's a hand filed Stihl RS chain. The saw was re-calibrated after each mod and a couple cuts made before the video was shot. I'm running E-Free 91 octane gas with 800 2T Off Road @ 32:1. I made two moderate load cuts and then two heavy load cuts. The 661 makes it's fastest cut times with a heavy load.

I started with a muffler that already had the factory port opened as much as the deflector will cover...left to right and front to back. The screen is intact to start with. I would never mod one with any less than this.


Here I have removed the internal baffle but left the screen installed.


Here I have removed the screen.


Here I have added a second port, actually a series of louvers, right in the center of the muffler cover.


With every change, I progressive made the muffler freer flowing. As expected, performance improved with every change. The MS661C loves to breathe, as do all chainsaws. With that said, I will be purchasing a new muffler cover as this one is too loud for normal use. The saw does just fine with the factory port opened up and the baffle removed.

Baffle In / Screen in - 4.99 average
Baffle Out / Screen In - 4.81
Baffle Out / Screen Out - 4.76
Baffle Out / Dual Port - 4.44

 

[Raganr]

What does too loud mean? To loud without ear protection?

 

[blsnelling]

What does too loud mean? To loud without ear protection?

I always wear ear plugs when running a saw, but this thing is bloody loud. It's basically shooting straight out the exhaust port and right through the front cover.

 

[HuskStihl]

Man, I'd love a 661

 

[Andyshine77]

Sounds good!! I'd leave it be, I mean how much do you really cut with that saw anyway.

 

[blsnelling]

Sounds good!! I'd leave it be, I mean how much do you really cut with that saw anyway.

"It's not how much you cut, but how fast you get done?

 

[Andyshine77]

"It's not how much you cut, but how fast you get done?

All of my saw are much faster than I am these days.[emoji6]

 

[blsnelling]

All of my saw are much faster than I am these days.[emoji6]

I can certainly relate to that!

 

[Stihlofadeal64]

Post a pic of the muffler front so we can take a gander

 

[johnny5ny]

Cool thread, Brad - thanks for posting.

I can relate to the noise issue. The last saw I bought, my 562, remains the only saw in the fleet with a stock muffler (albeit, screen removed).

It sounds good, does way more than I need a 60cc'r to do, and can be ran all day w/o hearing protection. The half second just isn't worth the noise for me.

Must be that gettin old thing

 

[whitedogone]

I love Brad pissing off neighbors threads

 

[Deets066]

I love Brad pissing off neighbors threads

...........

 

[whitedogone]

Out for a nice peaceful BBQ on the patio.....then ther's that MF again.

 

[SAWMIKAZE]

Quit pissin around with this 661 brad , You have other saws to play with that are more important

 

[stihlaficionado]

Quit pissin around with this 661 brad , You have other saws to play with that are more important

That's right…some of us would like to get our saws done by Christmas

 

[treesmith]

661 is just incredible, 8 pin with 25" and extremely low rakers(thanks groundie) in hard green gum isn't a problem

 

[blsnelling]

Quit pissin around with this 661 brad , You have other saws to play with that are more important

You're right, lol. I gave Friday night to myself. Today I'll be porting a saw.

 

[blsnelling]

Here's the current version of my 661. Cut times are a little off, but you can see the knot in the wood and can hear it holding more RPMs in the cut. I need another 661 here to test beside it.

 

[Trx250r180]

The loud thing must be part of the quad port stihls ,main reason i do not grab the 461 very often ,thing hurts my head ,my older saws are not as loud as the newer ones modded .

 

[blsnelling]

It's the placement of the louvers. They're directly in front of the exhaust port. I just ordered a new cover. I think I'll put just a couple louvers on the left side of this one.