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Echo cs-352

Horrigan72

Horrigan72

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I recently purchased an echo cs-352. Starts easy and idles well but 4 strokes in wood and I can't adjust it out. Pulled the limiter caps on the carb too. It will go in and out 4 stroking and into a tuned sound when cutting.

Saw has very little use. I picked it up cheap and I think likely sat with ethanol gas in it for an extended period of time.

Does the carb just need to be replaced? Are there other steps to take first? I really appreciate the guidance.

For reference I bought the saw to use in our orchard for my teen boys to use for tree trimming and cutting

I also have an echo top handle, Husky 346 xp, homelite 360 pro and a pioneer s50.
 
Timber MacFallen

Timber MacFallen

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I recently purchased an echo cs-352. Starts easy and idles well but 4 strokes in wood and I can't adjust it out. Pulled the limiter caps on the carb too. It will go in and out 4 stroking and into a tuned sound when cutting.

Saw has very little use. I picked it up cheap and I think likely sat with ethanol gas in it for an extended period of time.

Does the carb just need to be replaced? Are there other steps to take first? I really appreciate the guidance.

For reference I bought the saw to use in our orchard for my teen boys to use for tree trimming and cutting

I also have an echo top handle, Husky 346 xp, homelite 360 pro and a pioneer s50.
Hmm, well four stroking is caused by a rich mixture, but you say it's not responding to adjustment. That makes me wonder if everything is OK on the ignition side of the equation. You say it has little use, but I'd suggest pulling the spark plug and confirming it's not worn, damaged or excessively covered in carbon/fouled.

If the plug checks out make sure to do a spark test and ensure you're getting a nice healthy blue spark and it's not weak.

If the ignition and plug check out then I'd suggest draining the fuel, inspecting the fuel lines and replacing the fuel filter for maintenance and then pulling the carb off for a light clean and rebuild. If you're careful and it's not too old you should be able to re-use the parts. However, I generally recommend replacing the gaskets, diaphragm, etc when you go in.

Oh, and just confirm you don't have any blockage/obstructions on the exhaust and exhaust screen.
 
Horrigan72

Horrigan72

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Ok. I will run through everything you suggested. I have been looking and unable to find a rebuild kit for the carb? Doesn't even seem possible. Believe the carb is walbro wt 992. I find nothing searching the web.
 

Cliff R

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No direct experience with a CS-352 but Echo uses both rev-limiting and timing retard modules on some of their coils. I am NOT overly fond of either one as they can make it difficult to set the "H" speed screw.

Not sure about all that, however, IF you back out the "H" speed screw quite a ways the saw should start "blubbering" and 4-stroking heavily plus down on power. If not that part of the fuel delivery system inside the carb is plugged up and needs to be cleaned out. I'd do that before buying a replacement carburetor.........Cliff
 
Horrigan72

Horrigan72

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I removed the epa adjustment limiter caps and still can't adjust the issue out. I think you are correct that its something in the way of the fuel delivery side working properly. Going to get into it next week. Have to work all weekend.

Sent from my SM-G970U using Tapatalk
 

Huskitoter

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Can you try it with the air filter removed to make sure the filter isn't causing it?

Consider removing the carb. With the diaphragm off, put a length of hose on the inlet barb and blow into it while pressing and releasing the lever to see if the needle is seating. Adjusting the lever lower will reduce the amount of fuel supplied.
 
Horrigan72

Horrigan72

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Ok everyone. First thank you for the responses and help. Spark is good, fuel lines good. Checked everything suggested. I decided just to go out and run it through some wood. After 10 minutes of cutting running really rich (like it had been) it suddenly came right into tune and is running beautifully. I can't explain it. Not sure why. I assume something was stuck in the carb and it blew out.

Thank you you all.

Sent from my SM-G970U using Tapatalk
 
Goinwheelin

Goinwheelin

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It’s probably finally breaking in or maybe it was the Cat acting up. One of my cs400 was like that when I got it. Very low use saw maybe a tank or two thru it. Pulled limiters and couldn’t get it tuned for nothing. Said F it and just ran it rich like that and it finally cleaned up after a few more tanks. saw rips now.
 

Natster

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I assume something was stuck in the carb and it blew out
Thats a reasonable solution.
I've had a saw that would go lean occasionally. Open up the low mixture screw, suddenly it'd go rich. Closed it back to where it was, and it'd run just fine. Opening that screw let the junk past the screw.
You might try some Star-Tron in your gas. I've been very happy with it. I put it in all (most) of my small engine gas. It helps em run the ethanol/water on through.
Thanks, Nate
 

ericm979

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Check to see if you have a cat. Mine did but that was a few years ago. People have reported since then that 352s they bought don't have it.

Remove the muffler and look into the exhaust port side to check for the cat.

I used a burr grinder to remove mine. Use a hard one, I ruined a tool steel one. Wear a dust mask as the metals in the cat are not good for you. And make real sure you cleaned out all the filings. They can get sucked back into the engine and damage it.

I didn't see a significant performance improvement from removing the cat and fixing the limiters, but I did not open up the exhaust any. It's only a 34cc saw and I use it for brush, so it's more important to be quiet than to get an extra .02 hp.
 

Kenskip1

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Wood you like my opinion? Well here it comes. I suspect that the previous owner used a wrong oil mixture. To much oil in the mix. This produced carbon and it collected on the muffler screen and not allowing enough air thereby it seems like an overly rich mixture.. You finally got it hot enough to burn off the carbon and let the engine breath, thereby leaning it out and now running properly. Am I on the right track? Ken
 
Horrigan72

Horrigan72

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You may be. I will tell you this though. I had already pulled the screen but its a cat muffler so that could have carbed up maybe? What I didn't share is that I put about 4 ounces of seafoam in the empty tank and flushed the carb using the primer bulb then ran it for a minute choked to get the seafoam thru the whole thing. I hit the primer bulb a couple times a day for a week before dumping the seafoam and filling it with new gas and synthetic stihl oil. Was that the eventual fix? I don't know but maybe others do. Like I said before its had very little use. Couple tanks at most.

Here's a couple pics of the spark plug. If that helps at all.


Sent from my SM-G970U using Tapatalk
 
Timber MacFallen

Timber MacFallen

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You may be. I will tell you this though. I had already pulled the screen but its a cat muffler so that could have carbed up maybe? What I didn't share is that I put about 4 ounces of seafoam in the empty tank and flushed the carb using the primer bulb then ran it for a minute choked to get the seafoam thru the whole thing. I hit the primer bulb a couple times a day for a week before dumping the seafoam and filling it with new gas and synthetic stihl oil. Was that the eventual fix? I don't know but maybe others do. Like I said before its had very little use. Couple tanks at most.

Here's a couple pics of the spark plug. If that helps at all.


Sent from my SM-G970U using Tapatalk
That's a good looking center electrode in terms of color. Clean it off, double check the gap and put it back in and enjoy. Alternatively, it's a $3 NGK spark plug so you could also replace it if you like. Wear is minimal though.

I would however suggest if you suspect there was some old fuel in it (or if it's a few years old) replacing the fuel filter. Better safe than sorry and no need to starve an already factory lean engine.
 
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