[CS-590] Possible that, even at richest the *limiters* allow, that an out-of-box is running lean?

[Cerberus]

I aim to run my saws "optimal", I rarely err towards fat/lean, however my understanding is it's smarter to run a new/out-of-box saw a bit fat (and w/ extra oil)

My problem is that the carb's limiter-caps are such that, out-of-box, my carb's H&L were already both almost max'd out (fully CCW turned as far as *limiter caps* allow)

I did add a splash of HP Ultra to the echo canned-fuel I got for this 590 (for its first tanks, then it'll get the usual eth-free 95oc//HP Ultra//Stabil 45:1 mix I use on everything else), but I cannot get it out of my head that EVEN WITH the H&L at max, *because of the limiters*, that it's still too-lean....IE when playing with L while the saw is idling, and wanting to do the "back & forth" with the L screw to hear the "upper & lower thresholds" before setting it in that sweet-spot, I cannot richen it too-much to cause rough idling, the limiter gets in the way....

I'm guessing I know the answer but....I should NOT go cutting wood with this UNTIL I have removed the limiters and verified, by moving L both to the too-fat, then too-lean, then sweet-spot, that w/o that I should not even be considering taking this saw to a job yet?

Thanks a ton for insight, am at an odd position because my gut says that if the limiter prevents me from going too-rich, then I cannot really know if I'm actually at the sweet-spot, the sweet spot could be like 1/16th or more *past* the limiter and I'd never know because I cannot do the too-rich / too-lean "back&forthing" to set it!


(PS-- any tips on removing the limiters would be appreciated, I know last year I tried the "hot needle, then pull it out" trick on my 355T's limiters and it did not work I had to remove them in like dozens of lil pieces )

((PPS-- off topic but if anyone knows off-hand, I'd love to know if the 620's handlebars are a "plug&play" replacement for the 590?))

 

[Cerberus]

To be clear, this has NOT been muff-modded or anything (YET), aside from aesthetic stuff it is still bone-stock!!

 

[67L36Driver]

Everything that comes thru my door gets the limiters removed.

Two thin sheet rock screws turned in 180 degrees at a time alternately will Jack out the plastic sleeves.

A lean running saw pleases no one but the EPA which has far overstepped their mandate.[emoji2959]

 

[Ronie]

I use a drywall screw to pull the limiters, sometimes you need to snip the point off the screw because it makes contact with the needle before you have enough bite on the limiter. Don't know if you need to pull the limiters before you put it to work, it depends on if you can tune it with them in, you didn't really say how the tune is with the limiters in.

 

[Cerberus]

Don't know if you need to pull the limiters before you put it to work, it depends on if you can tune it with them in, you didn't really say how the tune is with the limiters in.

Really I thought I did The OEM ("with limiters") carb settings out of the box (off shelf, since it was floor-model) were fine, runs & cuts fine, doesn't sound 'off' to my ear and I cut more days than I do not. I did have to turn up (CW) the Idle about 1/16th to prevent idle-stallouts but that was it.

Problem (in my mind....that I may just be OCD about hence this thread) is that, for setting L, I like to hear/feel the saw go to both ends of too-much and too-little, and then I find my sweet-spot. Problem is that the limiter cap prevents me from the too-rich "fluttering out" setting that I would normally turn L to while doing my adjustments.

Saw doesn't sound lean, but I'm not used to a 60cc saw (climbsaws are 99.99% of what I cut with), and haven't brought it to a job because of nagging fear that even "sounding good" it may still be running "a bit" lean (and my understanding is that isn't that bad on saws once broken in, but bad during break-in)

 

[Ronie]

Really I thought I did The OEM ("with limiters") carb settings out of the box (off shelf, since it was floor-model) were fine, runs & cuts fine, doesn't sound 'off' to my ear and I cut more days than I do not. I did have to turn up (CW) the Idle about 1/16th to prevent idle-stallouts but that was it.

Problem (in my mind....that I may just be OCD about hence this thread) is that, for setting L, I like to hear/feel the saw go to both ends of too-much and too-little, and then I find my sweet-spot. Problem is that the limiter cap prevents me from the too-rich "fluttering out" setting that I would normally turn L to while doing my adjustments.

Saw doesn't sound lean, but I'm not used to a 60cc saw (climbsaws are 99.99% of what I cut with), and haven't brought it to a job because of nagging fear that even "sounding good" it may still be running "a bit" lean (and my understanding is that isn't that bad on saws once broken in, but bad during break-in)

I'm sorry, I didn't get what you were asking. If your in doubt, you should pull the limiters and tune it the way you like it.

 

[drumbum]

My understanding is these saws are difficult to tune lean due to the carb circuitry. Governed or .....

 

[pwheel]

I aim to run my saws "optimal", I rarely err towards fat/lean, however my understanding is it's smarter to run a new/out-of-box saw a bit fat (and w/ extra oil)

My problem is that the carb's limiter-caps are such that, out-of-box, my carb's H&L were already both almost max'd out (fully CCW turned as far as *limiter caps* allow)...<snip>

At some point the local Stihl tech advised me to keep the high speed setting on the rich side for the first 7 gallons of mix on a new saw. Remove or modify the limiter caps to suit. Once you own the saw, no more emissions tests; you can roll coal if you like. LOL.

 

[Mastermind]

The 590 is fat outta the box. Like so fat it won't rev past 12500 or so. You can close the high speed jet, and it would still be too fat. No way in hell that it's too lean.

 

[drumbum]

The 590 is fat outta the box. Like so fat it won't rev past 12500 or so. You can close the high speed jet, and it would still be too fat. No way in hell that it's too lean.

Yeah,....like that

 

[Wood Doctor]

The 590 is fat outta the box. Like so fat it won't rev past 12500 or so. You can close the high speed jet, and it would still be too fat. No way in hell that it's too lean.

Agreed. So are other saws, especially those outfitted with new carbs. Both my ear and my tach tell me that. Running rich at WOT must be the wave of the future. Not sure why.

 

[Nutball]

I think it is variable. From what I can remember, every 590 I've had had the high speed set at a good spot, and did not need adjusting stock or ported unless it was really hot or really cold outside. I think the low speed was lean on some of them. I had a 620p that was lean out of the box, but it was a cool time of year.

The limiters only give you 1/4 turn to work with, which is useless. If they had left off the tabs on one side of the limiters it would turn 3/4 of the way.

 

[Wood Doctor]

The limiters only give you 1/4 turn to work with, which is useless. If they had left off the tabs on one side of the limiters it would turn 3/4 of the way.

Agreed. It's as if the MFG decided that no owner should ever have to adjust a carb or no owner has enough brains to do it. That really disgusts me.

 

[Ketchup]

I think the limiters can be set arbitrarily, so it’s possible somebody at the factory just assembled the carb with the limiters in the wrong place.

BUT

My understanding is these saws are difficult to tune lean due to the carb circuitry. Governed or .....

/\ This.

The 590 is fat outta the box. Like so fat it won't rev past 12500 or so. You can close the high speed jet, and it would still be too fat. No way in hell that it's too lean.

/\And this.

Most Echo saws I have run are chronically rich. At the same time, they don’t flood to the point of not starting. They will die off full throttle and that usually means they need to be leaner. Turning the idle up is probably effective because it lets in more air. The adjustment range is very short and the edges are not very obvious even without limiters.

I got so frustrated tuning 2511t that I don’t tune by ear anymore. They always sound fat. I tune the low for the best throttle response and stability (usually with a pretty high idle) and then put it in wood and twist the H until I find the best speed.

I should say I work between 5000 and 10000 ft. Rich saws are more of a problem here in general. I’m pretty frustrated with Echo carbs.

Unless you’re trying to hold onto a warranty, Delimit.

 

[Cerberus]

If your in doubt, you should pull the limiters and tune it the way you like it.

Biggest problem is I know I like on paper and, til I can adjust that L screw to hear it too-rich, then too-lean, then too-rich again and find the sweet-spot, I was left worried that it was possible it was on the lean side, the limiters prevent any real disturbance while idling, their limitation is too severe..

My understanding is these saws are difficult to tune lean due to the carb circuitry. Governed or .....

This is awesome to hear since I'd always heard opposite IE that echo's are known "shipped lean", am very happy hearing multilpe opinions here to the contrary (Echo is my go-to, this is my 3rd unit, not for lithium obviously I wouldn't touch their lithium gear but for 'regular' they're my go-to!)

advised me to keep the high speed setting on the rich side for the first 7 gallons of mix on a new saw. Remove or modify the limiter caps to suit. Once you own the saw, no more emissions tests;

Re H settings.....True/False: You can run a saw wayyy too lean, at max-rpm, by keeping L turned in (CW) too tightly? Restricting too much fuel? Steve's Saloon (youtuber) has a video on tuning that is one of my go-to's, but upon rewatching today I noticed something worrisome, he says "H is strictly for speed at WOT", but that's not my understanding at all, my understanding is the speed at WOT is primarily governed by how much air you allow in via squeezing the throttle, and that if you do that w/ H too low, you're just running lean...and likely to be damaging your powerhead. He describes it like H is more of a "top speed setting" though...
(NOTE- thankfully, like the 355t I got last year, this also seems to have a limiter for max-RPM which makes me wonder why ALL good saws don't include such feature on their chips, anyway another "true/false", Does having a limited coil IE 15k max on my 355t, or 13k rpm max on this 590, mean that I'm basically 'safe' at WOT throttle as long as I never let it run lean? This thought has always comforted me, IE to err towards a bit fatter on H, since it just fouls/carbons stuff "downstream" and never risks letting the jug go w/o adequate lubrication...but maybe I'm looking at max-limiters wrong..)

The 590 is fat outta the box. Like so fat it won't rev past 12500 or so. You can close the high speed jet, and it would still be too fat. No way in hell that it's too lean.

Hearing this is so comforting, literally didn't use this because of the fear of that....am stoked to hear you replying here as, last year when I got my 355t, I read the *s-word out of your thread on the subject (still don't get why you didn't remove the plastic 'tab' behind the air-filter foam pad but maybe I missed a reply there will go check )

There's no point to me finding the anecdotes but had always read "echo's are shipped lean", "so and so scored the hell out of their carb because they ran their [echo saw] at factory-spec for a year", etc....so for instance w/ the 355t, and my plan w/ the 590, was:
- do mods (muffler opening, airbox opening with filtration of this opening), then
- remove limiters
- set carb appropriately
This^ procedure has no concern what the OEM/initial carb-settings are, I just set it after I'm done (I use a tach and ensure it's "basically where the paper specs say"...need to get a compression gauge and better tach, would love if you could recommend a non-high-end place for such things, that is better than ebay but not as precise as the gear you'd use!)

Thanks for replying, hearing this from you is greatly reassuring, would you still remove the limiters just to dial-in though? Hell I know people are imlpying to the contrary but once I muff &air-box modify this I have a hard time thinking that lil limiter-range will suffice for richening that...

Agreed. So are other saws, especially those outfitted with new carbs. Both my ear and my tach tell me that. Running rich at WOT must be the wave of the future. Not sure why

Because lean is dangerous and rich just means fouling plugs? I dunno, I had always figured limiters are awesome since they mean I can't hurt myself going too-high with H....and since I know(thought!) that I can hurt myself going WOT with too-low an H setting, this (limiters) made me think "great, I can err to the safer-side and, despite that extra fuel going into the equation, NOT have to worry about RPM going too high and blowing the engine"!!

every 590 I've had had the high speed set at a good spot, and did not need adjusting stock or ported unless it was really hot or

Humidity a big factor? I can run #'s (stock and after muff & airbox mods, probably done w/ all that today and will have a tach on it the whole time), am in humid-as-hell FL, and do pretty aggressive muff & airbox modifications, so am expecting the limiters' factory range will not suffice but will see will turn it on in between each step and observe RPM's at the two ends of the spectrum!

The limiters only give you 1/4 turn to work with, which is useless. If they had left off the tabs on one side of the limiters it would turn 3/4 of the way.

And I imagine 3/4 would be plenty? I ask because, after the nightmare of improper/amateur removal of my 355's limiters, this time I watched videos (still haven't removed them though) this afternoon and one video showed something OBVIOUS that I hadn't thought of -- simply pull the limiter, shave-off that nub, and re-insert! Then you have your cap w/o same restriction

Most Echo saws I have run are chronically rich.

Biggest problem w/ that is fouled plugs, right?

At the same time, they don’t flood to the point of not starting.

Hmmm, now that you mention it I've never had to "put aside" an echo to un-flood

They will die off full throttle and that usually means they need to be leaner.

Never happens w/ my polesaw or 355t (and I don't keep Idle up with the chain slowly spinning or just-ready to spin), am wondering why you'd ascribe such a situation to L/H (leannesss) instead of Idle speed?

Turning the idle up is probably effective because it lets in more air.

I got so frustrated tuning 2511t that I don’t tune by ear anymore. They always sound fat. I tune the low for the best throttle response and stability (usually with a pretty high idle) and then put it in wood and twist the H until I find the best speed.

Wouldn't best speed be the highest you can get it to operate at high chainspeed at? (that is a limited coil correct? Am jealous, already have a 25cc saw can't justify a 2511...yet )

Unless you’re trying to hold onto a warranty, Delimit.

Nope couldn't care less, in fact I dye (yup, RIT synthetic fiber dye!) body panels on my echo's, break-up that blinding orange LOL, so am guessing I blow my warranty claim position pretty quick that way

 

[Mastermind]

World record multi-quote right there.

 

[Nutball]

You can get limitless rotation by trimming the tabs off the limiter. Trimming one side would give 3/4 turn range. Just trim them all off. I find around here @ 700ft 3/4 turns out on the H screw is about right with a weather dependent range of about 1/2 to 1-1/4 turns. I can't remember where I set the L screw.

 

[Ketchup]

I see a lot of echoes with plugs fouled so bad they won’t start.

A saw that dies when you drop the throttle is crap. Sometimes they almost die. Usually dropping well below idle rpm and then recovering. To me that’s a sign the idle speed is fine but the mix is wrong during that transition from open throttle to nearly closed. A slightly lean mix usually struggles to drop down to idle speed. A rich mix usually blubbers, almost stalls and then returns up to idle speed. Plenty of room for debate there and either jet can cause that problem. Usually for me it’s the L.

The best tune for the H is the near fastest chain speed in the cut. So that’s where I tune them. In wood 80% of bar length. With a tach or just by feel. I usually go a little fat so I have more grunt when using the spikes or leaning on the saw.

I have worked on several 590s but I don’t own one. Your experience may vary from mine.

 

[Cerberus]

I see a lot of echoes with plugs fouled so bad they won’t start.

A saw that dies when you drop the throttle is crap. Sometimes they almost die. Usually dropping well below idle rpm and then recovering. To me that’s a sign the idle speed is fine but the mix is wrong during that transition from open throttle to nearly closed. A slightly lean mix usually struggles to drop down to idle speed. A rich mix usually blubbers, almost stalls and then returns up to idle speed. Plenty of room for debate there and either jet can cause that problem. Usually for me it’s the L.

The best tune for the H is the near fastest chain speed in the cut. So that’s where I tune them. In wood 80% of bar length. With a tach or just by feel. I usually go a little fat so I have more grunt when using the spikes or leaning on the saw.

I have worked on several 590s but I don’t own one. Your experience may vary from mine.

Thanks am so glad I posted I had read enough anecdotes of too-lean that it's nice to know it's virtually impossible, it does make me think "bad/non-pro carb" though when I hear "you can bed/seat the H screw and it's still not too-lean and still won't hit the RPM-limit"!

You say "a saw that dies when you drop the throttle is crap"....but that description is of carb-settings, not saws! I'm not saying you're wrong or anything (am able to tell you know far more than I do) but the way I understand it is that ALL carbs could be set that way (and that it's usually due to L being too-rich, causing the saw to load-up and choke-out/stall-out) Sounds like you're referring to a saw, by carb settings Would appreciate any clarifications you can give!

Re "near fastest chainspeed in-cut", may I ask why not aim for MAX speed? If too-lean, or too-high RPM, were concerns then of course not, but they're not concerns on the 590 so.....why not just peg H to whatever is true-fastest?

Thanks for the reply, I still haven't done 'final tuning' and was intending to do it with the bar fully buried, thanks for mentioning that 80%-buried line, will be doing that instead!

 

[Ketchup]

I don’t go to max because conditions change. The saw may lean out a bit more when hot or you may bury the bar and lean it out. I say 80% because I don’t like running bars that can’t reach across the cut. It would be more accurate to say I leave the bar nose out. It’s also just an average of how I might use the saw. Most of the time I’m not cutting 24” on a 24” bar. Sometimes 12”, 18”, 20”. Normally I just want to grab the saw and get stuff done so I tune for general good behavior over peak performance.
Your preference may vary.