Considering Muffler Modding ECHO CS620PW

[FR3]

Giving serious thought to a Muffler Mod for my CS620PW,

It's had about 8-9 tanks ran through it, I've already trimmed the tabs on the carb adjusters in an attempt to tune the carb properly. (set extremely rich from factory)
Currently the "L" is set at 1.5 turns out, and "H" is right at 1/2 a turn out. Even with H being only 1/2 turn the saw is still very fat... it 4 strokes out of the cut and i still hear it 4 stroking in the cut unless I really lean into it.

Couple Questions:
Does L 1.5 CCW, H .5CCW seem normal for the 620?

For those that have done the MM: Do you remember having the same issue tuning before MM? What would be a good baseline for tuning after MM? where did you find the sweet spot after MM?

Considering the many different ways to MM the 620, can someone recommend a particular Mod that will provide the best return in performance to noise levels?

Id like to gain as much flow as possible with out going overboard in the noise department. If possible I would also like to maintain the factory Muffler appearance, not a deal breaker... just a preference.

 

[Ketchup]

@Red97 has done a bunch of them.

 

[Red97]

I like removing the small lower deflector and adding a couple of small 1/4-3/8" holes in the flat part under the stock deflector.

 

[FR3]

Decided to give Red’s recommendation a shot. Trimmed the lower section of the deflector off, and 2 smaller holes. Gonna put the spark arrestor back in, bolt her up and tune the carb to see if I like it or want to do anything different

 

[JRenna]

That’s essentially what I did except if those 2 holes were one oval.

 

[JRenna]

I think you’ll like it.

 

[FR3]

I’ve ran about 6-7 tanks since MM and carb tune… so it’s had 15-16 total. It literally runs stronger every time I run it.
It’s pretty broke in now, and I couldn’t be happier with the performance.
It wears a 28” echo bar with full comp full chisel and I had it buried in 46” dead oak all weekend, never once bogged down, just slung chips.
This saw really wakes up when broken in, and the MM and carb tune completely turn it into a different saw.

 

[SXSBenzie]

I’ve ran about 6-7 tanks since MM and carb tune… so it’s had 15-16 total. It literally runs stronger every time I run it.
It’s pretty broke in now, and I couldn’t be happier with the performance.
It wears a 28” echo bar with full comp full chisel and I had it buried in 46” dead oak all weekend, never once bogged down, just slung chips.
This saw really wakes up when broken in, and the MM and carb tune completely turn it into a different saw.

How was the noise level? I took the smaller deflector out of mine, but didn't do the holes. Thought that might make it too much of a straight pipe.

 

[FR3]

its definitely a little louder … at first I wasn’t sure if I was going to like it…. But after bucking oak with it all day… I’m really happy with it overall.
It really wakes the saw up . So much so that I Muffler modded the CS400 as well.

 

[jcquade]

Giving serious thought to a Muffler Mod for my CS620PW,

It's had about 8-9 tanks ran through it, I've already trimmed the tabs on the carb adjusters in an attempt to tune the carb properly. (set extremely rich from factory)
Currently the "L" is set at 1.5 turns out, and "H" is right at 1/2 a turn out. Even with H being only 1/2 turn the saw is still very fat... it 4 strokes out of the cut and i still hear it 4 stroking in the cut unless I really lean into it.

Couple Questions:
Does L 1.5 CCW, H .5CCW seem normal for the 620?

For those that have done the MM: Do you remember having the same issue tuning before MM? What would be a good baseline for tuning after MM? where did you find the sweet spot after MM?

Considering the many different ways to MM the 620, can someone recommend a particular Mod that will provide the best return in performance to noise levels?

Id like to gain as much flow as possible with out going overboard in the noise department. If possible I would also like to maintain the factory Muffler appearance, not a deal breaker... just a preference.

I have the same saw. I almost wondering if the muffler mod affects the warranty

 

[ballisticdoughnut]

I’ve got a CS-600P I did the same muffler mod. Single hole above the stock pipe outlet, think it’s 7/16” if I remember correctly. Also removed the smaller deflector. It’s louder for sure but it really woke the saw up. Also did a red beard filter and gear head performance flywheel key. Carb is no longer semi fixed jet, swapped out the high speed nozzle. Very different saw now than it was stock.

 

[jcquade]

I have the same saw. I was wondering if the muffler mod affects the warranty

I wrote to echo customer support. They said any mod voids warranty. Looks like I will wait 5 years to do it. Bummer

 

[ballisticdoughnut]

There are ways around that.