Echo CS400 MM Question

[nomad_archer]

So I recently picked up a CS400 off of CL for $75. I want to use the saw as a learning saw and want to do a MM. I have read the other threads to and understand what is going to take. The one unique thing about the muffler on this saw is that the welds that hold the internal baffle and cat in have broken and are rattling around. If I manage to get the entire cat and internal baffle out will that make any difference once the saw is tuned? Or should I get a new muffler and remove the CAT only and follow the same steps that have been detailed in other threads?

Thanks

 

[cedarshark]

If you manage to get the cat and baffle out,I think it will be louder but shouldnt affect the saw if tuned correctly. I do have a CS400 but recently did a 450P and I left the cat and baffle on it and drilled additional holes under the deflector. That stuff rattling around in the muffler would bother me, especially if any pieces rolled back into the cylinder.

 

[nomad_archer]

Thanks cedarshark.

I did get lucky and none of the debris made it back into the cylinder. At least as far as I can tell. I just need to get a 1" hole saw now to see if I cant get the baffle out. Otherwise all the other grinding when smoothly. Once reassembled then I get to learn to tune for the first time. I have watched all of the videos so hopefully that step goes smoothly. But first to get the baffle out.

 

[mountainlake]

The CS400 has a limited coil which sounds like 4 stroking so make sure to start way rich and then gradually lean it out until it cuts the fastest in big wood. Steve

 

[nomad_archer]

Since I never tuned before I am going way, way, way rich to start.

 

[cedarshark]

Once yuo get it breathing better, it will probably run rich anyway. You may have to lean it some to clean out in the cut. My 450P neeeded leaning out some but I left it somewhat fat due to the new piston I put in it last week. Good luck.

 

[nomad_archer]

Thanks cedarshark.

 

[nomad_archer]

It's ugly but here is what I got out of the muffler. It took a 1 1/8" hole saw to get everything out. Now just to clean it up and put it back together.

 

[cedarshark]

Good job ! I'm glad you got that loose stuff out...it would have bothered me too. So now you have an empty can for a muffler. Ensure you wash it out good before you weld/braze your "plug" back in. If memory serves me, you are looking for your exhaust exit to be at least 80% as big as the exhaust port on your cylinder. That hole on the front of your muff is a tad on the big side Just jacking w/ ya.

 

[nomad_archer]

I washed out the empty can and blew it out with compressed air to get the rest of the junk out. I just removed the baffles on the output side. I didn't enlarge the exit at all. I cut for floor out of the deflector cleaned everything up and reassembled. I had no intention of putting a plug back in. The muffler will just be an empty can.

I just took my first pass a re-tuning. I made the L a little fatter to take care of throttle hesitation. Then I took the H very rich and leaned it out 1/16 or so at a time until it cleaned up in the cut. Or at least it is close to cleaning up in the cut. I will go back to it later today to listen again. It seems to be running pretty good now.

 

[cedarshark]

Good deal. Is it too loud ?

 

[nomad_archer]

Thankfully its not really that loud. I use hearing protection and I don't mind. It is louder than it was but it is a little saw so not bad .

 

[nomad_archer]

Here it is tuned with the help of some of the guys in the firewood forum

 

[o8f150]

maybe this vid will help,,, i did this one back in the winter,,,,,, once you get the cat out then you need to open the front of the muffler,, take the deflector off and open up the muffler to the same size of the deflector,,, now look through the front and you will see the cat can in there,, take a 3/8 or 1/2 drill and drill a hole straight through it right at the opening on the front through the can,,make sure you clean ALL the bits of metal out,, i cut the hump off of the deflector just to open everything up good,,, as you can see in my vid the before and after it really wakes the saw up,, throttle response and torque is improved by roughly 30% or more

 

[nomad_archer]

I did open up the the front of the muffler but only to remove the baffles on the exit. I did remove the deflector as well. The entire Cat and internal baffle are gone. Both broke loose and were rattling around in there. All I have now is an empty can for a muffler and less restriction on the exit. Saw is lots of fun to run now.

I may open up the exit a little more but I am going to run it a bit more as it is. It still improved a lot completely removing the cat and internal/external baffles and opening up the deflector.

 

[o8f150]

as long as you trimmed the limiters you will be fine,,, when you do a mm it will lean out

 

[nomad_archer]

I trimmed the limiters before I reinstalled them after re-tuning. I needed to adjust H and L screws. The L because it hesitated off idle when I got the saw.

I wasn't sure how much to open up the output port so I stayed conservative. It was my first time tuning as well so I left it a little rich.

 

[o8f150]

yep,, better to be to rich then not rich enough,,, you can always lean it out a tad later