Muffler Mod : 066 with pics

[Freakingstang]

I will do a series of post that pertain to Muffler mods. I will start with an 066, then a couple small huskies, a couple big huskies and whatever else I can find an improvement in.

He is the stock front muffler cover off of a newer 066. The Ms660 will be the same.

Here is the stock outlet on the muffler. This is the only outlet on the newer 066's and Ms660's. It measured a little over 3/8" diameter.

Here is the inside of the muffler. Notice that the exhaust gases have to come through the little holes at the bottom...

Here is the dual port muffler cover. You can see that the added port is about 3 times the size of the stock one port outlet. This is Stihl part number 1122 140 0800 and retail for right around $41.00

This would be the inside view (from inside the muffler)

This is the outside view of the same dual port cover

 

[Freakingstang]

Here is the modification I did to the stock outlet on the muffler case. I removed the spark arrestor screen from the muffler and used a die grinder to remove the material. The opening is about 1/2" (more on the + side). Be careful, as you want to remove the material from the back side. If you remove too much from the front side of the outlet, the gases will come straight out and burn the plastic. By keeping the hole towards the back, it allow the elbow to deflect the gases to the front.

This was another modification I did to the muffler case. I drilled a 7/16" hole into the plate, and die ground the corner holes open .

That should give you a little insite to mod your stock 066 or MS660 with the single port muffler. I reinstalled the spark arrestor screen in the main muffler body before reassembly. Be careful when bending the tabs that they aren't bent to far, as the could possibly break. They are what positively locate the screen in place. Good Luck!


Steve

 

[fishhuntcutwood]

Nice, clear pics. Thanks.

Jeff

 

[Freakingstang]

wow, 85 views and one response....Tough Crowd.

 

[Maxgussam]

How did these modifications affect the saw's performance?

Looks like a fast and easy way to get more power. Thanks for taking the time to post the photos!

 

[Freakingstang]

Good question MAX. The stock single port muffler on a newer 066 or MS660 is rated at 7.0HP and the dual port version is rated at 7.7HP. I have some vids of it in small wood (16" diameter) and as soon as I figure out how to get it onto my computer, I will post them. I wanted to try it out in larger wood (24" +) but wasn't able to before doing the mods. Going from stock to the dual port was a huge gain. Going from the "stock" dual port to the modded muffler opening had minimal gains, but was worth the effort.

 

[Maxgussam]

Interesting...

Knew the dual port muffler would give more HP, but I didn't expect that it would be that much.

I have a 660 that is now enroute to Washington Hot Saws for their Stage 2 mod package...can't wait to see how it runs!

 

[stihltech]

box

Remove the rest of the inside box at the muffler inlet.
Just leave the part the screws go thru.

 

[Freakingstang]

This has been a trial by error. I wanted to error on the side of caution first. once I have documented timed video, I will make more improvents, or at least try, vs just making it louder.


Steve

 

[Gologit]

Good pix...should clear up a lot of questions. How 'bout doing a 361 next?

 

[Freakingstang]

don't have a 361, or I would. Care to donate your saw?


Steve

 

[Gologit]

don't have a 361, or I would. Care to donate your saw?


Steve

Uh....No. Well maybe in ten years when and if I wear it out.

 

[Cut4fun]

Got the pine for gtg and cut some elm today.

Fstang you would loved to been where I was today with your size saws. A buddy said I could come get a big pine for my axe targets for WJ's gtg, if we used my saws to cut up a 28"-30" elm for firewood for him. Deal was done. Got me some fresh 22" white pine base cuts. That filled up the bed of my truck and he got enough firewood for a week out of the elm cuts to split. He couldnt believe how my 2 saws 54cc and 60cc poulans ran through the wood without bogging out. Single passes with 22"bars. Had to make 2 cuts on the elm though. Will post some pits when its day light again of the pine and hinge cut, to see what you think. To get where we were going was 4x4 time. Trucks covered in mud and had to drag one piece of elm back with a tow rope, we couldnt lift it and didnt want to do a ripping cut. The guy gave me 2 saws to bring back with me and said take your time and open them up for me and whatever else you can do to make his saws run better.

 

[rickyrooster]

066 muffler mods

thanks freakingstang, i enjoy seeing real pictures of muffler mods done instead of just reading about it. nice work.

 

[Freakingstang]

Good deal CUT4Fun. Maybe I'll bring my 55Rancher and Ms290 to the GTG to run against the Poulans.... :jawdrop:



That is what this thread is all about. Anyone can do it, and the gains are well rewarding. The more complicated stuff, I'll leave that for Gypo and the rest to show and tell.

 

[Lakeside53]

Interesting...

Knew the dual port muffler would give more HP, but I didn't expect that it would be that much.

I have a 660 that is now enroute to Washington Hot Saws for their Stage 2 mod package...can't wait to see how it runs!

There are couple of different muffler backs out there. Mine from 2002 had no internal baffle/box. I just added the dual port front and was very happy. The original muffler back that the dual port was made for (up to 1995 Magnum) had no internal box.

 

[Freakingstang]

Andy, did the 066 ever have a dual port muffler back like some of the 046 and 044's? I always like the dual "wings" on them.

I have also seen a differant style 066 and possibly 064 dual port front cover. It turned the exhaust gases down, instead of to the side.



Steve

 

[Lakeside53]

Not sure.... I have seen some odd ball 066 mufflers, but never really noticed if they were Stihl or some mod. Not sure you even need the side ports with the front open anyhow. I did some measurement and posted them to a thread last year - the front is sooo much larger than the side..

I've only every seen the 066 Factory Dual port front being to the side. There is the 064 muffler front, the - 801,... Maybe that's the one with the outlet "down"?

 

[Cut4fun]

pine pit

Heres the pine for axe target I am making for WJ's gtg.
http://www.arboristsite.com/showpost.php?p=405651&postcount=10

 

[Freakingstang]

Not sure.... I have seen some odd ball 066 mufflers, but never really noticed if they were Stihl or some mod. Not sure you even need the side ports with the front open anyhow. I did some measurement and posted them to a thread last year - the front is sooo much larger than the side..

I've only every seen the 066 Factory Dual port front being to the side. There is the 064 muffler front, the - 801,... Maybe that's the one with the outlet "down"?

I was thinking of the 046 style front outlet. I saw it at a dealer and thought it went down, but after buying the saw later on, it turns to the side.