Echo CS-400 Chainsaw Muffler Mods

[Chad Harding]

Echo CS-400 Muffler Mods

Here's the last slide!

Yeah I just opened up the back and frorestricter to the next one w myderemil and left the wire mess alone. It made all the difference in the world. Prob took under half inch

 

[Vail Ave]

I know this thread has been around for a long time. I recently modded my muffler and tuned my saw. It is an absolute amazing performer, and outperformed a couple other much bigger saws this last weekend. With the 18" bar completely buried in a 26" diameter ponderosa pine, it did not bog or flinch and really cut like butter. I did separate my muffler to remove the restriction. I also opened up 4 of the 6 internal baffle holes from roughly 1/4" to 5/16" - nothing too crazy. I also opened the outlet and deflector like most do. I did insert my spark arrestor screen and also carry a spare in my chainsaw box. I do a lot of cutting on BLM land for campouts so the spark arrestor must be installed. It runs great. To split the muffler I just ran it around my 1" belt sander to remove the lap seam. To re-assemble, I fusion welded it with my torch using .021" silican bronze filler and a 0 torch tip. I love acetalyne welding, so this was not an issue for me. You could TIG it as well. I ran my welds pretty cold to make sure I did not blow through. For this reason, I did not have the "stack of dimes" effect I normally like, but it worked great. If I did it again, I would split the muffler again. It really helps you see everything and clean everything out completely which took some time. If there is a little piece of metal still floating around in the muffler, the exhaust port and cylinder are only an inch away. Great thread, keep it up. I was thinking about adding a CS-590 to my fleet even though I do not really cut enough wood to justify it. But now, it is really hard to justify because this little 400 does so good, and it is so light and easy to handle, even for hours.

 

[Philbert]

I love acetalyne welding, so this was not an issue for me.

Welcome to A.S.! Not everyone can weld, or can weld sheet metal, or has a torch - you could make friends here on the site really quickly by offering to weld up mufflers that others have split open, and mailing them back!

Philbert

 

[Team FAST]

Nice job. welcome


Post some pics of your handiwork.
I have a CS-590 muffler mod thread you may be interested in.

 

[Cliff R]

"Great thread, keep it up. I was thinking about adding a CS-590 to my fleet even though I do not really cut enough wood to justify it."

The CS-590 is not even in the same league as the CS-400, so there is really no comparison between them anyplace, especially in the power output department. The CS-590 is basically a 60cc Pro saw with a laminated bar on it. I've been running the bag off of mine, it's stock other than a minor mod to the muffler deflector and removing the limiter caps and giving it some fuel. Spent the last few days cross-cutting some HUGE pieces of Ash to make them more manageable to get to the splitter. It noodles about as fast as it cuts in the normal fashion, and never even thinks about clogging up. I use the shavings for the nesting boxes in my chicken coup, and the rest around the house in the flower beds......Cliff

 

[Vail Ave]

I decided to do the muffler mod kind of last minute before a trip up north (both in direction and 6500 feet higher in elevation) to cut wood. I was in a bit of a rush to ensure I got it done in one night, so regrettably, I failed to take any photos of the internal muffler baffle, or any of the project at all. I will remove the muffler and show pictures of the outside. I will be quite embarrassed for anyone to see the welds. They are solid from functional standpoint, but again, I did not have a spare muffler, so blowing through not knowing the quality of the muffler can was my biggest concern. As mentioned, I ran things quite cold, which does not contribute to having the welds look nice. Not to get off topic, but on the subject of acetylene welding, which is an ideal method to re-join the two halves of this little muffler - a lot of folks that have the gear to live the rustic and strenuous life, have what we are talking about here - saws and an oxy-acetylene torch. Of all the friends I know that weld, most do not consider their oxy-acetylene torch rig to be a welding device. They consider it a cutting and heating device, and they only have the cutting torch head on it. Most have long since forgotten that their torch came with welding head and multiple tips. I totally get that - if I am in a hurry, I grab the mig. Done. But for many years, I practiced with my torch constantly and used it to weld anytime I could instead of more modern methods. I mention this because if you have a farm, ranch or shop and do have an oxy-acetylene rig - a.k.a - "gas-axe", "Tennessee speed wrench" or an "Arkansas Ratchet", re-acquaint yourself with the welding side of your torch system. It is an awesome resource. Most of the planes in WWI were built using torch welding. So, with a little practice, things like chainsaw mufflers are easy. I am way, way out of practice now. I have not done a lot of welding of any kind in about 10 years just due to lifestyle changes (married, kids, moved cross-country, etc), but it still only took me 10 minutes to weld this muffler, so those years of practice are still in my hands somewhere. haha.

I am pretty a pretty busy guy, but I am happy to help anyone I can get their muffler back together. If you live in an area where there is a shop that does welding that could gas or tig weld this little guy back together for you, they would probably charge you less than the cost of shipping this thing both ways. But if you have no other resource, I can weld it back together for you. What would be more interesting is to do a little video on it so that those who have interest in it can practice a little and then do it themselves if they do have a torch.

Since I don't have any pics of welding the muffler, here are a couple of me making a rear fender for my chopper. This was many years ago, but when it comes to gas welding, nothing has changed.

 

[Vail Ave]

Here are pics of the welded muffler.

 

[EchoCS400]

New to the forum here... I've used the old mans Jonsered growing up and have borrowed the father-in-laws Poulan but figured it was time to buy my own saw.

I just picked up a New Echo CS400, partially for the warranty and reviews... but from what I've read I should really consider doing the MM, tune it and forget the warranty.

I've used the saw a handful of times, starts and idles fine but seems to be leaving a little on the table if you bury it in the wood.
The reputable shop I purchased from said they "set it up", I haven't looked but i'm assuming that means they just turned the High all the way out that the screws allow.

Couple questions about the MM, is it really necessary to completely core the CAT? I've seen pics of guys just running a 1/2" bit on an angle towards the exhaust port with great results. I know some back pressure is always required and its easier to take more later than put back... and wide open doesn't always mean the most power.

In regards to tuning, I've got small engine experience from my dirtbike days so I'm sure I can handle it. Have any of you used a tach to setup the idle or Low adjustment? Or just setting the Low between lean and rich stumble?

From my understanding the Echo has a rev limiter so setting max RPM on the High with a tach isn't advisable.
Best to "tune it in the wood" for the High? Does the bury in the wood, then pull up to hear burble method work effective?

Any tips or recommendations would be appreciated, especially pics!

Thanks!

 

[Deleted member 149229]

I just picked up a New Echo CS400, partially for the warranty and reviews... but from what I've read I should really consider doing the MM, tune it and forget the warranty

The warranty is a joke. Lots of great threads on here how to tune and mm. You wont believe it's the same saw after you set it up.

 

[EchoCS400]

The warranty is a joke. Lots of great threads on here how to tune and mm. You wont believe it's the same saw after you set it up.

Looked at the saw when I got home... I was right. "Dealer tuned" just meant they backed the H and L screw out as far as the tabs would allow.

I think I've convinced myself to go ahead with the MM and tune. I've read way to many good reviews to not do it. I don't think I've read anything bad about the CS400's yet.

I'll continue my research on tuning, thanks!

 

[AnthemBassMan]

Looked at the saw when I got home... I was right. "Dealer tuned" just meant they backed the H and L screw out as far as the tabs would allow.

I think I've convinced myself to go ahead with the MM and tune. I've read way to many good reviews to not do it. I don't think I've read anything bad about the CS400's yet.

I'll continue my research on tuning, thanks!

I have your saw's slightly younger brother, the CS-370. I've already pulled the limiter caps from the carb screws and readjusted them. But I still have to drill through the cat to open up the breathing more. I'll probably just run a 1/2" bit through the cat towards the outlet instead of gutting the entire muffler. I've seen comments where it was done both ways with great results. And I'll be readjusting the screws once the MM has been done.

L8R,
Matt

 

[EchoCS400]

I have your saw's slightly younger brother, the CS-370. I've already pulled the limiter caps from the carb screws and readjusted them. But I still have to drill through the cat to open up the breathing more. I'll probably just run a 1/2" bit through the cat towards the outlet instead of gutting the entire muffler. I've seen comments where it was done both ways with great results. And I'll be readjusting the screws once the MM has been done.

L8R,
Matt

Keep me posted with your results. I'm new to the saw world, but feel this is a necessary mod for these saws.

 

[AnthemBassMan]

Keep me posted with your results. I'm new to the saw world, but feel this is a necessary mod for these saws.

Will do. From everything that I've read, it only helps wakes up this series of saw. Haven't read a single thing where it worsens the performance.

L8R,
Matt

 

[Deleted member 149229]

I removed muffler and with a Dremel removed restricter plate on muffler, drilled hole thru cat towards exhaust port (ther's a plate in there). Then removed exhaust cover and again with a Dremel made the exhaust one hole by removing slats. Then tune. Not the same saw.

 

[EchoCS400]

Had the saw out this weekend and knocked down half a dozen trees for campsite firewood. Most of it was 6"-8" Poplar... and some larger deadfall.

Haven't had an issue running it in stock form as of yet, doesn't bog out but I'm curious to see how well it will run once I do the muffler mod.
I'm not one to leave anything alone, and can't handle "leaving performance on the table".

Will report back once I get time to do the gut the muffler and tune!

 

[Team FAST]

Here are pics of the welded muffler. View attachment 526869 View attachment 526870 View attachment 526871 View attachment 526872 View attachment 526873

Welds look good. To match the flow numbers I got from the testing, you should enlarge the opening to the outer exhaust deflector to be rectangular.

 

[Gardy]

So I have the tools/ability to modify the deflector outlet, but not the internal baffle. Would doing just the deflector mod be any help? Thanks in advance!

 

[Deleted member 149229]

So I have the tools/ability to modify the deflector outlet, but not the internal baffle. Would doing just the deflector mod be any help? Thanks in advance!

Just drill holes thru it.

 

[pdqdl]

This is an old thread, but apparently there is still some interest in reading it. All the original pictures seem to have been lost.

If anyone still has the original pictures, it would be great if you could add them to a new post in this thread. Thanks!

 

[ATpro]

You can drill the cat out with a 7/8 hole saw, use a sheet rock screw to pull limiter caps on the carb. You may pull the plate off where the limiter caps are but if you do just push it back in and it will stay. Grind off the raised tabs on the limiter caps and put back on the carb adjuster screws, this will help keep the carb adjuster screws from moving from vibration but you can still fully adjust the carb.