Echo CS-400 Muffler Mod and Limiter Cap Removal

[dsell]

7/8" carbide hole saw and wire brush for the drill. The limiters were a pain to get off. I ruined one of them and got a new one. Ruined meaning, a screwdriver wouldn't turn it. I'm not sure if they always have that plate? I ground off the limit tabs and pushed them back on the carb. If you don't do that, it will be painful to hit the screw head and tune it.

 

[dsell]

And the rest. Opened the high and low screws at least 1/2 turn. I'll finish tuning the next time I go cut.

 

[dsell]

Try to help explain something I didn't understand. There is a heavy metal pipe in the center of the muffler. You use the 7/8" hole saw to gut that pipe and then I cleaned it with a wire brush. As you open the deflector side, you start hitting the cap on that heavy pipe. Some of my opening is blocked by the end of the pipe. The pipe has 6 x 1/4" holes. After all the grinding, I blew it out with compressed air, washed it in hot soapy water, then blew it out many more times.

 

[Abbeville TSI]

Good job! My grandson has a CS-400 I need to modify like that. Personally, I think removing the cat and opening the exit like you did will be enough.
Perhaps we will hear about the pipe from someone else more knowledgeable...

 

[lee_the_wyrm]

Looks good. I just took the limiters out, including that small grey piece. Why put it back in? I recently did a muffler mod on my CS491 and it's a noticeable difference for sure. Don't forget to retune or you might be running lean. I ran it for five minutes after the mod and it sounded pretty lean at the standard 3 1/8 turns out on the H screw.

 

[Bubba scooter]

I modified the muffler to be 80 percent of the exhaust port size (at the cylinder wall) and removed the limiters on my new cs400. Bingo! Cutting time improved 30 percent and the operating temperature of the cylinder dropped 90 degrees. Muffler temperature fell 110 degrees. That catalytic converter is a saw killer.

 

[FlyingDutchman]

That cat is a pain to remove. Welcome to the club

 

[dsell]

Looks good. I just took the limiters out, including that small grey piece. Why put it back in? I recently did a muffler mod on my CS491 and it's a noticeable difference for sure. Don't forget to retune or you might be running lean. I ran it for five minutes after the mod and it sounded pretty lean at the standard 3 1/8 turns out on the H screw.

Easier to hit the larger plastic screw surface. The screw head left after removing the plastic barely resembles a screw head.