New CS352--tuning and muffler mod advise

[Echo]

Hi everyone, I got a new cs352 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 and a little spot of soot
closer to the outlet.

I fell the saw has a slight bog coming off idle, it was so bad when I started the saw from new,

that I needed to take out the low screw 3/16 of a turn, this helped a little,

now this bog is a slow motion one that clears slowly and is subtle.

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, if I take out the L any more am afraid the
idle will become uneven, it has done so  already from my initial 3/16 turn to get her
off the line, I idled her up to compensate, but still not as good as before the L adjust.

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.

Is the fuel filter in these 352 's restricted some how, the way the subtle bog clears
slowly may be a fuel restriction from the tank, the seller / dealer says some of them
do not completely clear, this makes me think am not the only user to have mentioned
this to him, he also said to pull the trigger steadily rather than just gunning it.

Edited March 4, 2019 by Echo

[Echo]

Anyone using one of these, having similar experience, or not.

[wyk]

I will not run a saw with a cat. In my opinion, it is one of the worst things you can put on a 2 stroke engine. Even if it improved the power, I would remove it because any extra heat on the exhaust side of a 2 stroke will shorten it's life, and a cat is a LOT of extra heat. But you may not want to hear that. So...

A cat does take time to heat up depending on the application. So if you shut off the saw every time you set it down, use it in cool outside temps, and do not run it for more than maybe a minute at a time, it may not be bad. But the cat will still decrease exhaust flow.

 

This is what a STIHL cat looks like once it's warmed up:

 

 

[Echo]

Thanks wyk, I can't stand the idea of a cat in there at all, seems like the worst

idea ever in a two stroke engine.

I took the saw back to the dealer, I showed him the slightly black plug,

he said it was a small bit rich, so he leaned out the H, said the plug would

be ok to use, so am just going to run it, I told him I considered it way too hot

and that I was trying to avoid coming back with it burned up, he said Echo

would cover it, that they run this hot, not overly happy, but if i remove the cat

then I will end up with no warranty.

I find this saw very odd, the bog has gone now after another hours cutting,

I put my tach on it,  the same tack I used yesterday when it read 10,800 is now

jumping all over the place, eventually settling at 10,200, the saw definitely is

four-stroking less,  the dealers tach showed12,400, so how on earth am I getting

a lower reading, given the saw was leaned out, the Echo dealer has ordered a new

tach which I will get him to put on the saw when it arrives, still does not explain 

why my tach which worked on my cs501 and all my other non mt at saws is 

now jumping and reading too low when it was fine yesterday.

[Paul in the woods]

I've had a 352 for about three years now. I'm only a domestic user so can't really say if it's getting hot compared to other saws but there's no damage and the plug looked fine when I removed it. It's run on Aspen 2 and had 80+ tanks through it.

 

I've tached it and when warmed according to Echo's service guide it was 12000 rpm, and when I checked after extended use it was just over 12500. If it's tached after starting then about 11000.

 

The only problems I've had with it was problems caused by a service which were quickly sorted.

[Echo]

Hi Paul, thats a lot of fuel through your saw, am only at 3 tanks yet.

what ratio of petrol to oil do you run, what brand is your 2 stroke oil.

THANKS

[Paul in the woods]

It's not a huge amount of fuel as the tank is only .25l. As mentioned, I use Aspen 2, so alkylate fuel premixed with Aspen's 2 stroke oil 50:1.

[Echo]

Good to know 50:1 has served you well, a lot of people use much more

oil to help lubricate, I will too after I get my job done and have time to

address whether to de cat or find a non cat muffler.

Yes .25L is not much, mine seems to go through it quicker than I thought it would.

So I guess am not too lean.

[lurkalot]

On ‎05‎/‎03‎/‎2019 at 22:39, Echo said:

Good to know 50:1 has served you well, a lot of people use much more

oil to help lubricate,

And a lot of people use more oil than they should and seize them up due to running leaner and hotter. Use the recommended mix is my advice, combined with the right oil.

[spudulike]

11 hours ago, lurkalot said:

And a lot of people use more oil than they should and seize them up due to running leaner and hotter. Use the recommended mix is my advice, combined with the right oil.

Have you ever experienced anyone seizing a saw through too much oil? In my experience, saws running too much oil generally don't rev properly and smoke like a pope has been voted in. I have found this over oiling mostly on home owner or farmer saws and have never shown signs of getting overly hot - most have oily deposits around the muffler and often have an oily residue in the carb.

Personally I don't see over oiling seizing a saw but do mostly see seizure through old fuel, straight petrol, air leaks and poor carb adjustment.

No oil in the fuel creates friction, creating heat and piston meltdown and too much air makes a saw over rev making too much heat thus melting the piston!

I am interested in this and may use a 50:1 and 20:1 in my saw and take a thermal reading off the cylinder top and see what really gives as I really don't see an over oily petrol mix allowing an engine to create too much heat as in my opinion, right or wrong, too much oil just stops an engine revving and makes it smoke.

Had this on another thread and interested to substantiate and prove the fact!