Echo CS-590 doesn't stay running at idle

[thumbtack]

Hello,

I have an echo CS-590 (Timberwolf) that is only a few years old and not used all that often. Maybe 2 years ago I was using it quasi-regularly, and one day, it was just really hard to start. I could kind of get it running if I held down the throttle but it felt like it was bogging down at idle. It turns out that these saws are sensitive to doing things like trying to start it with the kill switch on or whatever, but I didn't know that at the time so it felt like ti very suddenly stopped working. I fiddled with it for a while, cleaned the carb, etc. and then put it away for a year or so.

Picked it back up a few months back and it was still hard to start so I did some digging, and ended up finding out that dropping some oil into the chamber can help reseal the rings or whatever, so I tried that and it helped a lot. Now the normal starting sequence (choke on, pull 1-2 times until it kicks, turn choke off and start) works fine and as long as the high idle is on, but then when I kick the high idle off, it runs for about 5 seconds and then dies. Every time.

I've tried basically everything. I've tried cleaning the carbs, fresh gas, I've tried redoing the idle/high/low screws (although I would also take more tips on how to properly set those! this carb is weird), I've tried rerunning the lines to eliminate kinks, etc., I've taken it apart and put it back together 100 times in case something was pinched, etc. It still starts fine but dies as soon as it's asked to idle.

I'm running out of things to try and I'm getting a little frustrated Any help would be appreciated. What else might be causing it to die at idle?

Thanks!

 

[pioneerguy600]

What is the compression like, have you looked at the piston through the exhaust port?

 

[thumbtack]

Compression is about 150 I think, I haven't looked at the piston but I can!

 

[pioneerguy600]

Compression is about 150 I think, I haven't looked at the piston but I can!

You should.

 

[Brushpile]

Hello,

I have an echo CS-590 (Timberwolf) that is only a few years old and not used all that often. Maybe 2 years ago I was using it quasi-regularly, and one day, it was just really hard to start. I could kind of get it running if I held down the throttle but it felt like it was bogging down at idle. It turns out that these saws are sensitive to doing things like trying to start it with the kill switch on or whatever, but I didn't know that at the time so it felt like ti very suddenly stopped working. I fiddled with it for a while, cleaned the carb, etc. and then put it away for a year or so.

Picked it back up a few months back and it was still hard to start so I did some digging, and ended up finding out that dropping some oil into the chamber can help reseal the rings or whatever, so I tried that and it helped a lot. Now the normal starting sequence (choke on, pull 1-2 times until it kicks, turn choke off and start) works fine and as long as the high idle is on, but then when I kick the high idle off, it runs for about 5 seconds and then dies. Every time.

I've tried basically everything. I've tried cleaning the carbs, fresh gas, I've tried redoing the idle/high/low screws (although I would also take more tips on how to properly set those! this carb is weird), I've tried rerunning the lines to eliminate kinks, etc., I've taken it apart and put it back together 100 times in case something was pinched, etc. It still starts fine but dies as soon as it's asked to idle.

I'm running out of things to try and I'm getting a little frustrated Any help would be appreciated. What else might be causing it to die at idle?

Thanks!

I'd take it to an Echo dealer. Mines a certified repairman but I haven't needed him

 

[singinwoodwackr]

Sounds like a carb issue. Do you have a sonic tank? Cheap at HF…
disassemble the carb…( no need to pull the throttle and choke flaps, just the main parts including the h and L screws. Inspect the valve for wear, pull the screen as well. put all the parts into a small plastic container filled with carb cleaner like Berrymans . Add water to the tank but not enough to float your container. Run it a full cycle. Flip the carb case over and run it again. Blow out and reassemble. Sometimes all it takes is a tiny speck of crud in one of the internal passages.

 

[thumbtack]

Sounds like a carb issue. Do you have a sonic tank? Cheap at HF…
disassemble the carb…( no need to pull the throttle and choke flaps, just the main parts including the h and L screws. Inspect the valve for wear, pull the screen as well. put all the parts into a small plastic container filled with carb cleaner like Berrymans . Add water to the tank but not enough to float your container. Run it a full cycle. Flip the carb case over and run it again. Blow out and reassemble. Sometimes all it takes is a tiny speck of crud in one of the internal passages.

Thanks. Kind of a dumb question, but how do you remove the H and L screws? Mine look like they have some odd plastic cover on them and they can only turn about 1/4 turn. Don't want to force anything if this is how they're supposed to be...

Also, what do you mean by "a full cycle"?

Thanks!!

 

[singinwoodwackr]

Thanks. Kind of a dumb question, but how do you remove the H and L screws? Mine look like they have some odd plastic cover on them and they can only turn about 1/4 turn. Don't want to force anything if this is how they're supposed to be...

Also, what do you mean by "a full cycle"?

Thanks!!

Sonic tank has a timed cycle…at least mine does.
you may need to get the manual for your saw from Benson (beg for manual, thread) and learn how to get those limit caps out.
or, try YouTube
last time I did a 590 it wasn’t too hard.
One way to do it…

 

[Cliff R]

The limiter caps are easy to remove and this should happen BEFORE the saw is placed in service. This allows the operator to fine tune the "L" and "H" screws for best idle quality, throttle response and full throttle power without running the saw too lean and damaging the P/C. You can very carefully "pick" them out with a scribe by lining up the tabs on them with the openings in the retainer, or just engaging them with sheet rock screws and pry them out. EIther way works fine. Once out just grind the tabs off and re-install them and the retainer if it was removed, they aren't fussy.

The CS-590, 600 and 620P carburetors have a check valve in them that will make them not idle well if at all when it goes bad. I like to replace them here with the variety that aren't drilled. This provides full control with the "H" speed screw plus they are undercut all the way around and you don't have to worry about lining up the feed hole during installation.

If the P/C looks good when the muffler is removed and you can't find any problems elsewhere after putting a kit in the carb and removing the limiter caps and fine tuning, replace the check valve. You can test the valve, several Youtube videos on checking and replacing them but I just put new ones in here anytime I'm into one of those carbs as standard procedure........

 

[singinwoodwackr]

One guy plugged the hole with a dab of JB Weld

 

[thumbtack]

Thank you all. I got the screws out and was able to clean under them for the first time. Unfortunately this didn't help the issue, so I'm thinking check valve.

I'm happy to replace it, but can't seem to find much info about it. I've gone through the pats diagrams for this carb and I don't see a check valve and some web searches seem to say that it's not offered as a standalone part. Where is the check valve located and can I test it to see if it's still good, or should I just replace? Is there a preferred source, since I can't find the part number anywhere?
Thanks!!

 

[singinwoodwackr]

Thank you all. I got the screws out and was able to clean under them for the first time. Unfortunately this didn't help the issue, so I'm thinking check valve.

I'm happy to replace it, but can't seem to find much info about it. I've gone through the pats diagrams for this carb and I don't see a check valve and some web searches seem to say that it's not offered as a standalone part. Where is the check valve located and can I test it to see if it's still good, or should I just replace? Is there a preferred source, since I can't find the part number anywhere?
Thanks!!

Might be easier for you to just replace the carb.

There are a couple YouTube vids, however, that go through the process

 

[user 172763]

Search this forum for Echo CS590, there is a whole thread about a replacement valve with the part number for the "upgrade" valve.

Search Results
https://www.arboristsite.com/search/212645/?q=echo+carb+valve+replacement&o=relevance

 

[thumbtack]

Search this forum for Echo CS590, there is a whole thread about a replacement valve with the part number for the "upgrade" valve.

Search Results
https://www.arboristsite.com/search/212645/?q=echo+carb+valve+replacement&o=relevance

Thanks. I see a lot of threads about replacing the H jet, but nothing about replacing the check valve. Is the check valve part of the H jet or am I just missing a thread somewhere?

 

[user 172763]

The very FIRST one in the search, you have to read some of them.

Replace Carb Check Valve on CS-590?

https://www.arboristsite.com/threads/echo-590-timberwolf-h-setting.301438/post-7741206​

I had a problem with my pressure relief valve sticking open. That was when it was brand new, was hard to start, dealer gave me a replacement, but when I started to take the old one out, I just lubricated it instead. Spray on graphite. It's worked flawless ever since.

 

[user 172763]

https://www.arboristsite.com/threads/echo-cs590-not-holding-idle.364543/post-7889821

 

[vizette]

Thanks. I see a lot of threads about replacing the H jet, but nothing about replacing the check valve. Is the check valve part of the H jet or am I just missing a thread somewhere?

The check valve was done to help avoid people leaning the saw out and melting the piston by turning in the H needle too much. It feeds extra fuel to the high side regardless of the needle, so basically you're talking about the same thing. It's notorious for causing issues with both idle and H tuning when it fails or when someone blows it out with compressed air while cleaning it.

Be aware though, once you pound out the old one and seal it up with the one that ChasSC posted, you'll need to open up that H needle quite a bit from its stock setting or you will burn it up because it won't be getting the extra fuel that the check valve was letting through. Always start rich if unsure, if it doesn't four stroke wide open, you need to open it more right away.

You could buy a new carb but you'll be in the same boat down the road, whereas the replacement part is only $8 or so vs a whole new carb so it's not like it's breaking the bank if it doesn't work.

 

[Cliff R]

If you end up buying a replacement carb the larger carb for a 620P fits and works perfectly. It's the HDA-316 instead of the 268 (going by memory here so don't bust my balls too hard if those aren't the correct part #'s...tks..) If you keep an eye out on Ebay they come up for sale on occassion for around $80. Forget the Chinese copies, total pieces of Bovine Excrement as well as a complete waste of you time/funds.

I keep a few check valves in spare parts and have made it standard procedure to punch out the stock one and put a new one in every time I get involved with one of those carbs.......FWIW.....

 

[ClimberBusinessman]

I'd recommend adjusting the L (low) and T (idle) screw on the carburetor or possibly replacing the carburetor. If you take the air filter cover off, on a CS590 they should be located to the right-hand side of the saw, and there's three screws, the H, L, and T. The T screw is the main one you'll probably need to adjust based on the symptoms you've described. If you have a tachometer designed for 2-stroke engines (you need one that can read up to 13 or 14,000 rpm), you can use that to set the baseline RPM at idle and maximum RPM to the recommended RPMS.

 

[user 172763]

I fiddled with it for a while, cleaned the carb, etc. and then put it away for a year or so.

In your first post you stated you cleaned the carb, then put it away for another year. Exactly what do you mean by you cleaned the carb. Actually rethinking this, I would try a rebuild kit. It's easy to do, and if it was running before, and you didn't change any settings, may be likely they are stiff.