Echo CS-590 Caution

[hatfield]

My neighbor purchased a 590 after he made a few cuts with mine. He loved it. I made it a point to run my tach on his saw out of the box. His saw as well as mine, was set way too lean as stated by others on this site. So, that's 2 for 2 that were lean. The "H" screw was set CW all the way on his, and mine was 1/4 turn CCW from full CW.
So, anyone who has one, or is considering purchasing one, please make sure you pull the limiter caps and set the carb correctly. It appears right now that both of these saws are running their best at 12,000 rpm (no load) Pulled the plug to confirm this on both saws.
I need to get a few more tanks through mine and continue using the tach to see if this will change. I'm almost sure at this time that you should not set the RPM higher than 12,000 on the 590. It appears anything higher is too lean for these saws. I would like to hear from other's that use a tach, and report what their saw is set at.

 

[Red97]

13,800-14,200


14,800-15200

Just a tad lean for my liking.

Stock ones do like 12,200-500.

Stock carb loves to feed the fuel, bout the same range as the 590 coil 13,500 max. Has a bypass, so it will not completely lean out, but it will scorch the saw over time. Aquired 2 of them like that.

 

[hatfield]

That's just a tad high on the ported saw. Great video. Thanks for sharing.
Yes, seems the stock carb does pretty well. I'm loving the 590 the more I cut with it. One hell of a saw for $360 to my door.

 

[bmwpowere36m3]

Mine came with the H set full CCW against the limit stop... which turns out be ~ 1/2T out (with the limiter removed). I've only got two tanks thru mine and the muffler deflector modded.

Since I was under the impression the coil is limited, I set the carb very rich to start (differentiate limiter vs. 4-stroking). I buried the 20" bar in some wood and with a little fiddling on the H screw... 4-stroking was clear. Initially it 4-stroked thru the cut, then a small adjust, still 4-stroked, etc.

I kept turning it in a little, till it would lightly burble a couple times thru the cut. Left it like that since for break-in. So its still a little rich, but I don't think I'm far off the stock setting.

 

[Andyshine77]

The cab used on the 590 has a system that will proved just enough fuel, even with the needle seated. The revlimiter makes tuning with a tachometer a bit more difficult, tuning in the cut as described above it the best method.

Sent from my HTC One_M8 using Tapatalk

 

[hatfield]

Same here. Tuned it while the bar was buried in the cut.

 

[Red97]

The cab used on the 590 has a system that will proved just enough fuel, even with the needle seated. The revlimiter makes tuning with a tachometer a bit more difficult, tuning in the cut as described above it the best method.

Sent from my HTC One_M8 using Tapatalk

Yep, seems they added that feature to the 620 carb too.

13,500 is all I could manage from either carb. Pig rich, with the H closed off.

 

[hatfield]

Correct. The rev limiter does make tuning with a tach more difficult. Approximately 12,000 rpm is the no load rpm after both were tuned as well in several cuts with the bar buried. I gradually turned the "H" screw CW during each cut for the sweat spot on the saw. I now have 5 tanks through mine. I'll see how it performs as the number of tanks increase, and the temperature starts to drop over the next few weeks/months.

 

[hatfield]

Yep, seems they added that feature to the 620 carb too.

13,500 is all I could manage from either carb. Pig rich, with the H closed off.

Don't know how you were able to get 13,500 out of the 590 with the rev limiter ? The highest RPM I saw was 12,600-12,700

 

[hatfield]

I'm going to cut out the deflector today leaving the screen in, and see how the saw cuts, making any adjustments as needed throughout the day.

 

[Red97]

The 590 rev limiter is 13,500 +/- 200 you should be plenty safe.

Think you will really like it once fully broke in.

Very nice saw's for the $$, and mod well. Only knock I can see with them is air filtration, and antivibe. Compared to the more expensive 60cc saws.

 

[Red97]

Don't know how you were able to get 13,500 out of the 590 with the rev limiter ? The highest RPM I saw was 12,600-12,700

That was most likely the carb feeding the fuel.

Swear the coil was limited to 13,500. May be mistaken, could be 13,000.

Will swap the 590 coil back on and check it.

 

[hatfield]

Yes, agreed. Great saw for the money. We shall see where it ends up once fully broken in. I'm with you. I don't like how the air filter mates with the air filter case. After every cutting session, there's visible wood dust seated where the filter hole meets the case. I'm going to see if I can find an "O" ring that will fit vs. putting grease in that area. Poor design in my opinion. Don't like the stock bar either. That will be changed out when needed.

 

[James Miller]

My 590 ran fine out of the box. I didn't pull the limiters till I opened the defector noticeable gain just from that. May pull the base gasket next as everything I read says the squish is huge from the factory.

 

[Termite52]

Call k&N air filter company and talk to customer service about making you an air filter for your car-590

 

[randy hines]

Any advice not already here on tuning my cs590 h screw in the cut, im exaust mod and limiters removd. Sometimes the chain stops when im starting into the cut?

 

[eye.heart.trees]

Any advice not already here on tuning my cs590 h screw in the cut, im exaust mod and limiters removd. Sometimes the chain stops when im starting into the cut?

Honestly i think the best/only real advice is "watch more carb-tune vids and get better at tuning" :/ That said, and FWIW I barely have any time on my new 590 and also still tuning it but despite there being a lot of talk about "too lean" settings on this site, on other sites (*********) and youtubers (tinman's saws) the line is "they're set too-rich, not only that but the carb (both 590&620) has a 'bypass' for H that, even when you fully seat the H screw, will not allow you to over-lean the saw" Also plenty of anecdotes of people not being able to lean-out enough to even hit the rev limiter WOT-no-load..
Again am not even that good at tuning myself am always fiddling w/ my carbs & never feel confident tuning, but that said they all start, idle and cut well & reliably, I'm attaching a 590-specific carb-tune graphic you may find helpful it's a close-enough approach for carb tuning in-general (are you using a tachometer? I do, although I'd be lying if I said i thought it was doing me much good, I'm using the feel of the in-cut power and especially the sound to tune 9/10, not the tach, and that's with the tach perma-mounted to my saws )

Good luck also is your muff mod open-enough? I see people removing the deflector but calling it a muff-mod, the deflector needs to be removed to have a proper escape-port from the muffler, but does nothing to change the tube/straw style path this muff makes for the exhaust gases! I copied tinman's mod but am planning to patch that and do a more...'thoughtful'...mod than simply dogging a hole in the top of the muff opposite the OEM hole!

PS-- the fines-through-filter-gaps is no joke with this saw, I'm not even on tank #3 yet and found some fines that got past and I'd used heavy marine-grease on all filter-interfaces, am GG to hardware store(s) today to find the ideal rubber-washers, thinking thin&tall, soft rubber to really squish-into-place with the closure of that 1 kinda-weak retention screw for the air-assembly, will post washer part#'s if I find some that are ideal and easy to order online

 

[eye.heart.trees]

To the OP and everyone in the "these echo's, at least 590/620 series, are lean lean LEAN" camp, could you help me reconcile your sentiment with the sentiments on OPE(outdoor power equipment forums), and on the Tinman's youtube series on the 590 he recently finished, that they cannot lean it out too-much even when trying??
I genuinely think I may be misunderstanding some important elements of lean/fat insofar as:
-- total air+fuel 'charge' coming through that intake manifold, and:
-- the relative air//fuel ratio the carb's venturi is feeding to that manifold,
I'm thinking these may be different and account for my misunderstanding here (heck, even for the case of Tinman saying how "he cannot lean it out enough to hit the rev limiter", but subsequently using it with the H screw set like 1/2 or 3/4 CCW, that confused the heck outta me because I'd have presumed he'd have simply left the H screw seated "if it was already too-rich even when seated"!)

Thanks am eager to understand this better, had lost my 'zeal' for saw-work after rebuilds/maintenance/etc got routine for me, but feel like a kid in a candy store again now that I'm trying to get into customizing/boosting some of my powerheads

 

[Daniel Sherman]

Don't know how you were able to get 13,500 out of the 590 with the rev limiter ? The highest RPM I saw was 12,600-12,700

I did the muffler mod, and gearhead timing advance key with the 620 carb on my 590. I had it tuned under no load at, 13,290 rpm, but once in the cut, I had to move it back ccw for the sweet spot. So now not under load its around 13,030. MATT ROBINSON (gearhead) makes parts and works on these 590's , he said the saw does its best at around 12,500 rpm. I have a cheap Chinese tach, so I wouldn't doubt it if Mine ain't actually setting at 12,500