Stihl 026 stock muffler - amazing the saw even runs!!

[davefr]

I modified my 026 muffler and was amazed the saw even ran with the factory design. (ie one tiny 3/8" diameter muffler port!!)

My little 021 has about twice as much muffler passage area as the stock 026!!

I bored two adjacent holes and then engraved them into an oval shape with a Dremel tool and a carbide bit. I also cut a "V" in the outlet baffle plate. The saw runs great and I didn't have to re-jet it. (it's slightly louder but not that bad)

Thanks for the suggestions!!

Has anyone modified an 046 muffler. Does it suffer from the same aenemic design as the 026?

 

[treeclimber165]

I'm getting ready to tackle an 046 muffler. My boss has two 046's and the one that runs has a cracked frame (gas tank/rear handle assy). I got one on the way from a fellow arboristsite member. The other one I'm going to look at this weekend, and open the muffler after I get it running. Depending on results, I may do the other one too.

 

[treeclimber165]

046 muffler

I just got my boss's old 046 running. Besides years of abuse and neglect, the only reason it hasn't run in 6 months is a bad spark plug. Runs like a bat outta He11 now. Can't turn it over without the decompression button.

I opened the muffler out of couriosity and found NO BAFFLES! Only 2 outlets with spark screen over them. I guess it's an older model, still has both adjustment screws on the carb with no caps.

When I open the newer 046 I will probably open up any baffles I find, if any.

 

[yorkpaddy]

Can you show some pictures of what you actually did. I'm gonna get an 026 soon and I want to do the mods

 

[davefr]

Sorry, I have no pictures but it's real easy.

1. Use a #27 Torx screwdriver to remove the front half of the muffler.

2. Look at the inside of the front cover and you'll see one approx. 3/8" hole.

3. Drill 2 more holes above and below that one. Use a Dremel tool and a carbide bit to make the 3 holes one continuous oval opening.

4. You can also use the Dremel tool to cut out a "V" shaped notch in the outer spark arrestor plate but the only way to do it is from the back side of the muffler. (I don't consider this step too critical)

4A. Remove all metal fillings/fragments/dust!!

5. Re-install the muffler and put a drop of thread locker on the two Torx screws.

6. Start the saw and make sure the carb. adjustments are accurate. You might have to go a tad richer on the low speed jet.
(www.madsens1.com/sawtune.htm)

Maybe the group's professional "power tuners" have a better method, but this is what I did.

Originally posted by yorkpaddy
Can you show some pictures of what you actually did. I'm gonna get an 026 soon and I want to do the mods

 

[treeclimber165]

046 muffler

I got my boss's newer 046 put together yesterday. The frame had cracked where the top handle bolts on underneath. It had been run over or something before I worked for him. (Thanks, Husky2100, for the 046 frame!) Only other part I had to buy was one front rubber mount.
While I had it apart, I looked in the muffler. Unlike the older version, it had a baffle with an opening approx. the same size as the exhaust port. I almost doubled the size of that opening using a drill and flat file. The outer exhaust opening was a single hole about 3/8". I drilled a second 3/8" hole next to it, and then filed out the area between the holes to make an oval opening approx. 3/8" X 7/8".
After what I've heard here about exhaust sucking as well as blowing, I also replaced the exhaust screen.
Then I started looking for some big wood to cut! Low and behold, I ran into an old friend later in the day who had an oak trunk laying in his back yard left over from a removal last year. The guys got paid and never finished hauling the big wood, it was too large for my friend to move. I went over and burned a full tank of fuel in about 30-40 minutes. MAN that 046 rips!

Full comp chain on a 28" bar, rakers filed down to about 28-30/thousands, and I was throwing up rooster tails of sawdust 6-8 feet!
Thanks to everyone here for all the advice and all that I have learned!