New CS-352 tuning and possible muffler mod info

[Firewood]

Hi everyone.
I got a CS-352 with a 14 inch bar and 91 vlx chain.
Ran just over a tank of fuel through it, let the saw run before shutting down.
The saw being new, I pulled the plug to ensure all was well.
First off I never felt as hot a plug or engine top.
There was a hint of oil on top of the piston.

I put a tach on the engine and it tops out at 10,800, spec says 12,500 max,
so am on the safe side regarding fuelling, the seller said not to open
the saw up much above 11,000, as they do run very hot, and the more rpm 's
the hotter they get.

Wondering what you all recommend.

This is the only saw I have with a cat, am quite sure its contributing to the rather
hot running, but its new and I am hoping there may be things I can do other than
removing the cat.
Though I would like to hear how to address the cat for later, does it need to be cut
out, or is a large hole drilled through it enough.

The plug has only a shadow of black near the bend where it
connects to the threaded part of the plug, everywhere else looks good, a small blotch of
black on the piston near the outlet, looks odd that its only in one spot, the rest looks
dry all but a very slight glisten from what must be oil/fuel on the piston, only looked
through the plug hole, very difficult to take a picture, only got a phone.

 

[Nutball]

I've heard Echos supposedly run bad when new. I don't remember any of that with any of mine, but maybe just give it time? Go ahead and experiment with the needles till it runs right. It might be helpful to count and write down how many turns out the needles are, in case you need to reset. Count the turns as you turn the needles closed, then write it down and turn them back out that amount.

 

[Firewood]

Thanks Nutball
I just took the spark screen out of this 352, its a little sooty around the edges, so am definitely
too rich, will be turning in the L a little, will put a tach on and see if the rpm 's picked up any,
if not I will lean up to 11,000, that dam cat is a huge restriction, I can see why echo has the saw running at 10,800, there is absolutely no way that saw could breath running at the 12,500 top they give with that cat in place.
Looks like it will be a muffler mod after all, I looked for a second hand muffler so I could keep my
own stock, only new ones, and they cost a lot for what they are.

 

[huskyboy]

I think those have a cat in the muffler which would explain the running hot and even the bog maybe.

 

[Firewood]

Hi huskyboy

Yes, it has a cat,, there is just no way this saw will run cool with that blockage,
no wonder its tuned to 10,800 from the shop, its impossible for it to breath.

 

[huskyboy]

Hi huskyboy

Yes, it has a cat,, there is just no way this saw will run cool with that blockage,
no wonder its tuned to 10,800 from the shop, its impossible for it to breath.

On my string trimmer it has a cat but it was too difficult to get out without splitting the muffler in half, so I just ground through the baffle bypassed the cat. Made a difference. What’s it look like inside the echo muffler?

 

[Steve]

The c352 has a metalic honeycomb type cat. Eaisily removed with a 3/4 holesaw. Remove the muffler and look in the inlet. The cat will be staring you in the face. 10,800 can also be too lean on the high side. Remove the cat and the limiters on the carb. Open the high side untill the rpms drop. Then turn it in to the highest reading and then open it an 1/8th of a turn. Adjust the low for best idle and accel off idle. Put it in some wood and make sure it runs well under load.

Thats how i tuned my cs352. Its a great trim saw.

 

[Nutball]

I've been coming to find more Echos in the USA have no cats. My 352 doesn't have it, my 2511t doesn't. I can see a red hot cat in my muffler modded 271t where I just bypassed it, so they do radiate lots of heat. It glows even at idle.

My 352 didn't gain much from a muffler mod, the big restriction was the port design and compression, but then again I have a non cat muffler.

 

[Firewood]

Thanks everyone for posting.
I took the saw back to the dealer, showed him the dark coloured plug, he said it was running a little rich, leaned it out, he put his tack on it, it read 12,400 and still four-stroked some. I told him that I think the saw runs way too hot, ceramic and all, the head is hot too, he said Echo would cover it, they do run this hot.

I took it home, run it for an hour, no more bog down, and cuts great, it idles not as good, oddly it did none of this in his shop when he leaned it, it was real smooth. I took it home and immediately noticed the above, and my tach that read 10,800 yesterday is now giving 10,200 after it settles down, which takes ages for it to do so, am a little puzzled.

 

[Firewood]

On my string trimmer it has a cat but it was too difficult to get out without splitting the muffler in half, so I just ground through the baffle bypassed the cat. Made a difference. What’s it look like inside the echo muffler?

From images I have seen on line, the cat is the full of the cylinder outlet,
so unless one removes this obstacle of a thing, then there is no way to bypass it,
what ever leaves the cylinder has to go through it unless I remove it.

 

[Firewood]

There is no limiters on this saw.
I have never removed a cat, do not even know what the material is like to drill with
a hole saw, am hoping its not too tough, does it drill cleanly, or role in front of the
cutter like aluminium can do, would be nice if the cat was on its own frame that was
just spot welded in, removing the spots would be cleaner, just weld up the holes after.

 

[Firewood]

My 352 surprised me in how well it cuts, glad it is a 352 though instead of the smaller cc model.

 

[Nutball]

Some Echo mufflers have space around the cat to drill bypass holes, not on the 310 through 400. Echo mufflers can be thicker and harder than you think. The Cat itself will tear up really easily with a drill bit, but that might risk metal shavings flying back into the engine somehow.

A video of it cutting and of full throttle revs for a few seconds at a time will help us know what it is doing. I can usually figure rpm with in 100rpm from listening.

Chainsaw engines can run 180-240 degrees F, I have a blower that runs 320F. You can't easily touch anything 180F and higher, or hold 115-135F for more than several seconds at best, so I would expect a plug to be too hot to touch.

 

[Nutball]

Yea, the 310 SUCKS so much. It's terrible. My ported 352 though is pretty fun, and it isn't even maxed out.

 

[Nutball]

Mine stock got 10900rpm

 

[Firewood]

Thanks Nutball
If I was not trying to keep the warranty, I would soon cool this saw down
a bit, yes, the danger is metal fragments being left in the muffler, that is why
if all is well with this saw when am finished my job with it, I will look for a
non cat muffler, I have seen them on line, expensive enough too, maybe an Echo
dealer would be able to get one just as cheap with no cat, will see how it goes.

 

[Firewood]

Mine stock got 10900rpm

That should not have been lean then, mine was slightly below this when I got it.

 

[Nutball]

I got 13,600 in a lean test run of my 352 after modifying it, but it ended up cutting a bit slower. That was as lean as I'd feel safe running mine, it could go a bit faster, but that rpm was more easily acheived from other modifications. It might be a good tune for limbing soft evergreens, but the ~10,900 tune cut a bit faster in 15" hardwood.

The 400 is a good saw, but also has a cat, at least in the USA.

Maybe @AlfA01 could get you a non cat 352 muffler?

 

[Firewood]

Not happy, had to order a plug, dealer said the old one was ok yesterday, and added that a new one was costly, regardless of cost, a new saw that messes a plug is really not up to me to replace, when I heard that comment about the price of a plug, I got a glimse of what lays ahead, was there a reason for not changing the plug.

 

[Nutball]

Video?