Echo CS-400 Chainsaw Muffler Mods

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seems like the flow data is better with the screen out and no deflector


im going to go that route

It is, but on an otherwise stock saw with a properly tuned carb, I don't think its nescessary. You still want a slight flow restriction in the muffler to maintain a little exhaust backpressure to assist with exhaust scavenging. Too much is not always the right answer.

-erik
(aka Team FAST)
 
If you look in the original team fast slides it looks like the cat was cut/drilled out kind of sloppily.

Not really. The picture makes it look worse than it is. The ragged appearance is actually the exhaust gasket residue. Polishing the interior is not nescessary...diminisihing returns and no measureable flow difference. The cross sectional area is so large in that section as compared to the exhaust port that it won't have any significant impact on the flow. I cleaned out the center large bore with a sanding drun and a flap wheel.
 
how the hell do i get to those baffle holes? do i need to split the muffler and braze it back together?

No, the holes can be opened up easily without splitting the muffler. Clamp it firmly in a shop vise with some leather or couple of show rags. Use a hand drill and open up the holes. It will grab when it goes thru, so make sure the muffer is clamped securely and you have a good hold on the drill.

I reached in and cleaned up the holes with a long shank round carbide cutter on an air grinder.

I've modded two of those mufflers, takes about 20 minutes. I put the deflectors back on them, just opened them up some.

It's a big wake up call for those saws. My muffler modded CS-370 was faster than a stock CS-400 in timed cutting tests.

I really like the CS-370/400's, but they are not in the same league as any of my 50-55cc saws, not even close.

They do have a LOT of "grunt" for such small saws, and great for limbing. I run 14" bars on both of mine, with 3/8" LP chains......Cliff
 
heres one i did last fall on one i gave to my friend al. i ended up totaly gutting everything out of it (i cut it open:doctor:), made a couple of braces to fit between the 'halves' out of tubing and redid the deflector. i used 1/2" o.d. stainless tubing for the ports (about 3/4" long). silver solder works perfect.
1ie87d.jpg

the saw falt out rips compared to what it was with the cat in there, and it's as loud as a homey xl12.
 
Bump

Hello Everyone!

Been a really long time since I've posted here, and I just re-read this thread and thought that it needed a bump to the top again for anyone who owns an Echo cs-370, or cs-400. Since the last time I posted I installed a baliey's Arbor Pro 16" bar (down from the stock thin radius 18" bar) and Bailey's Woodland Pro 16" chain. Wow, what a difference the more aggressive chain makes... I absolutely love this setup and I think I might buy a 14" b/c to play with as well. These Echo saws are unstoppable with the muffler-mod described in this thread and a little proper carb tuning goes a long way as well. Thanks very much to TeamFast, and all the others that have contributed. I think I am going to buy myself an Echo 600p as a new toy soon, the porting video that blsnelling did on youtube is pretty awesome for the 600p, looks very nasty! Anyone port the cs-400? Anyhow, lets keep this thread alive for anyone looking to buy/wake-up their CS-400, what a difference a little muffler mod and more aggressive b/c make on this little 40cc saw, great limber, great felling saw for smaller stuff, and great for hoisting up in the tree when you need something a little more powerful than your little tree saw, (like my CS-341). This is a powerhouse of a 40cc, absolutely awesome all around small saw.

Have a good rest of your weekend guys,
Adam
hlc03
 
Just modded my buds cs 400 i forgot how badass they sound when you mod the muffler. I have not put it in wood just yet. Im trying to talk him into giving me the saw, after i do a bb kit on a makita for him.
 
Restrictive Echo Mufflers

I actually just found this thread, somehow missed it when it started.

I have been opening up the smaller Echos for several years; and oh my, what a difference. I have a few CS-346's, that had the about the same catlytic converter. Took them out of all the saws, worked on the deflector and removed the screen.

The CS-345 is the same saw, before catlytic converter; if you find one of them, use that muffler and do the deflector and screen work.

I have a new CS-530 but haven't even run it yet; but will apply the Team Fast procedure to it too.

Also I am thinking about getting a new CS-500p. Has anybody worked on any of these yet. It is the Shindaiwa/Echo project.
 
the last slide where it says, "40cc Echo now hangs with 55cc saws!"

You haven't run too many 50cc saws have you? Let me just suggest you change that slide.

Kind of a old thread that I missed, Zombie should run a muff modded CS400 and then comment. I ran my CS400 against my Rancher 55 53c which the CS400 beat easy, against a good running 029 56cc that I sold (no reason to keep a 18# saws when a 13# saw will cut just as fast) it was just about dead even with the 029 winning by a hair. Steve
 
Man this is temping....... On one hand I really want the extra power(insert Tim the Tool Man Grunt) but I'm a little nervous about voiding the warranty. Thought's on that issue?
 
Just GREAT! just moved up from homeowner saws and used my cs-400 for 3/4 of a tank and now I have to mod the muff! I cut 4-5 cords of firewood last year and now every year in future and theres no way I'm gonna let that cat muff cause excess heat in my new baby's engine. Funny since I chose this over husky for warranty now it's gonna be gone!
 

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