Think saw might be taking on air @carb...idles up&down, carb-setting is beyond me :/

[Cerberus]

Saw is 1.5yrs old but I do use it pretty hard (and as my default saw), it's a clone of a zenoah g2500 if it matters (the Scheppach version, has been a champ til this week)

First I found my idle was higher than it shoulda been...I do turn-up my Idle now&then before a climb if it's the type of thing I fear getting up there & saw not starting but am pretty good about turning it back (so maybe I upped the baseline Idle, or maybe it began taking-on air which'd change my kinda-fat carb settings to a faster, more optimal ratio by introducting air /eliminating the slightly-rich conditions I set for it)

I then tried tuning it...total nightmare. I cannot even keep it running (at any H&L settings) without keeping the Idle in a position where the chain's spinning (can put my tach on it if a reading would help, to me it was just "needing to have chain movement for the thing to stay alive, is no bueno/not a problem of carb-settings")

I "got it tuned" as good as I could but it still sucks, will stall out if I try revving in the first 30sec after a cold-start....it's super sensitive to carb changes or rather Low changes on the carb (H can be set in-cut normally enough), and has exhibited this weird behavior where I know it "can" rev&cut but could also "fall out"/stall, so I kinda "feather the trigger" to get it revving lightly for a second then start giving it more gas and it'll go fine (this will happen w/o changes to the carb, happens here&there with the saw as it stands right now)

Air manifold leak? The gap between the airbox housing and the powerhead itself (which is a pivoting gap on most top-handles I've ever seen) is no longer an even gap IE it's clear I've put force into the unit, but I noticed that gap nearly a year ago and it doesn't seem to have gotten worse...

Thanks for any insight on what to do, I have other top-handles but I love this lil guy it's my go-to saw I hardly notice it on my belt I don't want this guy on my bench any longer than necessary!

(*should note that the Off switch stopped functioning recently...I choke it to turn it off. Also about a month ago I swapped-back to eth-free, from canned fuels....this saw got canned fuel for most of this year. Air filter always kept clean and I use permatex to seal it so the intake manifold's insides are especially clean!)

 

[Moparmyway]

Throw it in the garbage and spend the $$ for a quality pro saw. You’ve been playing around with Chinese parts enough to conclude that they will, inevitably, not perform the way they should

 

[Nutball]

I've found a lot of 2 strokes will stall if you try to rev after a cold start. I'm not sure what causes it, maybe fuel tank pressure needs to form in some designs? My poulan blower does it, and I know an Echo 400 that does it, but both have the H/L tuned properly when warm. Maybe the gas doesn't like to burn when cold. You are supposed to let stuff fast idle on half choke for 10-30sec after a cold start according to most intructions.

 

[Ford3000]

If you eiminate the air as you say by tuning it lean and increasing the idle, then it wont
take throttle too well, it will still be lean.
Take the idle screw away from the throttle arm , then screw it in until you touch the lever a little.
That will eliminate the possability you are using the idle screw as a prop to keep the engine running.
Then fatten up the Low by turning it out until you get the saw started, let it warm up, adjusting a cold
engine is useless.
When warm set the Low where you have good throttle response and it idles reasonabley, it should not
hunt up or down, then stop and start the saw to ensure you can.
Then turn your attention to the H setting, set it to you are four stroking out of the cut, and when you cut the fourstroking goes away but immediately comes back when you lift the pressure off the saw.
There will be a point where you come off the low and onto the high as you pull the throttle open,
you want as smooth a transition as possible, if you jump onto the H like a turbo kicking in, then the low needs fattened a bit, some saws have a jump regardless, its better to not have much if you can.

Idling up and down, take a spray can of penetrating oil, with a long straw attachment, accurately spray
around the carb boot with the engine runnng, if it dies when you spray, its sucking in air,
also air gets in around the crank seals, similarly spray around them and listen for a change in engine tune.

Have you tried putting the saw on its side and releasing the fuel cap when its running, be carefull you
dont start a fire, if it cleans up then fuel vent.

Have you a clean fuel filter in the fuel tank.

If the saw is old, the carb diaphram could be hard, or stretched and hard.

 

[Cerberus]

Throw it in the garbage and spend the $$ for a quality pro saw. You’ve been playing around with Chinese parts enough to conclude that they will, inevitably, not perform the way they should

Not the case here actually! While I did purchase this $135 unit because going and buying a $700 saw was out of my reach - also seemed silly when it was my 1st top-handle and I wasn't exactly sure what I wanted in a nicer unit and would be getting more units shortly thereafter - I cannot make a single complaint against this saw. @afleetcommand has a good youtube on his g2500 clone (mine is the Scheppach version, lacking the faults that his Jon Cutter version has/had), these lil guys are actually awesome saws I use mine as my default saw, it gets pushed, and has *NEVER* given me an issue in nearly 2yrs now!

I've found a lot of 2 strokes will stall if you try to rev after a cold start. I'm not sure what causes it, maybe fuel tank pressure needs to form in some designs? My poulan blower does it, and I know an Echo 400 that does it, but both have the H/L tuned properly when warm. Maybe the gas doesn't like to burn when cold. You are supposed to let stuff fast idle on half choke for 10-30sec after a cold start according to most intructions.

Sunny FL seems to eliminate any 'normal' colder-starting issues (unless you explicitly meant 'unstarted machine'? If so, these issues haven't given indication of being temp-dependent)

If you eiminate the air as you say by tuning it lean and increasing the idle, then it wont
take throttle too well, it will still be lean.
Take the idle screw away from the throttle arm , then screw it in until you touch the lever a little.
That will eliminate the possability you are using the idle screw as a prop to keep the engine running.
Then fatten up the Low by turning it out until you get the saw started, let it warm up, adjusting a cold
engine is useless.
When warm set the Low where you have good throttle response and it idles reasonabley, it should not
hunt up or down, then stop and start the saw to ensure you can.
Then turn your attention to the H setting, set it to you are four stroking out of the cut, and when you cut the fourstroking goes away but immediately comes back when you lift the pressure off the saw.
There will be a point where you come off the low and onto the high as you pull the throttle open,
you want as smooth a transition as possible, if you jump onto the H like a turbo kicking in, then the low needs fattened a bit, some saws have a jump regardless, its better to not have much if you can.

Idling up and down, take a spray can of penetrating oil, with a long straw attachment, accurately spray
around the carb boot with the engine runnng, if it dies when you spray, its sucking in air,
also air gets in around the crank seals, similarly spray around them and listen for a change in engine tune.

Have you tried putting the saw on its side and releasing the fuel cap when its running, be carefull you
dont start a fire, if it cleans up then fuel vent.

Have you a clean fuel filter in the fuel tank.

If the saw is old, the carb diaphram could be hard, or stretched and hard.

Hell yeah!! Thanks Will be able to do this....soon!!
Know how I said It wants to spin chain @idle just to run? I'd figured it was due to me messing with Idle speed, but that wouldn't account for why, sometimes when idling, the chain speed would go up/down (or it'd go from moving to not moving) Figured I'd open-up the clutch cover, make sure nothing was impeding the clutch and giving me false-impressions about my carb.....and found:

frickin' clutch spring missing I'd kinda bent it when previously removing clutch (I'd overdone it w/ cleaning it, using too much carb-clean spray too frequently and washed-out the grease, got a squeek, had to remove clutch & regrease, my clutch removal tool nicked a spring and I got it back in-place - worked for many many months - thing finally gave!)
So yeah that explains the erratic Idling (and all my settings were based off an assumption of smooth idling, of course) so thankfully parts for these are next to nothing (it's actually <$20 for the whole clutch assembly, not just a spring ;D LOVE this saw's parts-availability!!!)

 

[Nutball]

I don't know how cold an engine has to be to act that way, but maybe even 120ish degrees might be "cold" enough, and like I said, it could be a tank pressure or some sort of prime issue when it hasn't run in a while.

 

[Maintenance Chief]

I'd say you got your money's worth, if you've used it pretty hard .
If you want save this particular saw instead of just buying another one, I'd pressure test it.

 

[Cerberus]

I am IN LOVE with this saw/platform!! Had thought I was likely to get a 2511t if/when this unit failed me but now I'm not so sure.... Does anyone know any other top-handles that have such steep upward bar-angles? One of the things I like about it (a unique/specific thing, I mean...) is that steep upward bar angle, I wouldn't want that on my 355T w/ 18" bar but for a 10" or 12" bar I realllly prefer it and the g2500 class seems to be the only option for that specific feature..

Loving it so much right now because of the parts. I mean it's closer to 2yrs old than 1yr and has been a default saw for me that entire time and it's never broken anything (even suffering drops from height! My 355t also took a fall maybe ~20' and was also OK/didn't show signs it'd fallen) but, if/when stuff happens, the parts-market for this platform is frickin' unreal -- I paid $11 (total) on Monday (after 12p, too) for a new clutch and got it yesterday!! Was ETA'd for Sat., which I was already psyched about as I expected "cheap, but 2wks from China" (which 4/5 of the parts are, including these clutches - though you can get them closer to $5 apiece from China, also was surprised to see there's even 8T sprocket/clutch-drum pieces available!)


Anything "extra" I should do while having this all opened? Will get pics of my cylinder for critiques, will clean and put heavy marine grease on the roller-cage bearing thingie that sits between the shaft//sprocket assembly....otherwise it's just "Plug the piston, swap it out and then tune it up"

Has been interesting without it, I have a 14"/32cc unit b
ut it weighs same as my 355t which has an 18" right now so it's been my default, definitely has its pro's but man it's heavy (like any 35cc+ top-end climbsaw is, they're all 8lbs give/take a tenth pound, actually think the 540xp is a touch heavier but it's also more displacement/HP too....have seen the 355t beat it though )

I don't know how cold an engine has to be to act that way, but maybe even 120ish degrees might be "cold" enough, and like I said, it could be a tank pressure or some sort of prime issue when it hasn't run in a while.

Gotcha Re temps, wanted to be sure i was on same page. How would I test this? The unit has a "breather tube" that I figure is a crude type of pressure-vent, it was initially a ~2" rubber tube that ran vertically on front-face of the powerhead (usually covered by this dumb "bumper" they put on these units, lets them mount dogs I guess? But wastes 1.5" of bar-length and when 10" bar that's 15% usable bar-length and who needs dogs on climbsaws?) It had a screw or bolt in its end, so some pressurized gas could escape but it didn't leak/seep. The thing did eventually break off so I put a lil golden screw in it (bottom-right of front of powerhead)


its low height makes me think it's gotta be an oil breather....but if there's one for oil I imagine there's one for fuel! Would love to hear any/all ways I can check for pressure there, had only understood pressure in terms of the cylinder itself and still need to order a damn gauge (just recently found out that some saws can pick-up compression, and max RPM, as they age....I **know** this unit is stronger than when-new, w/o a doubt, would love to do an A/B test!!!)

 

[Nutball]

Why would you want the bar angled up? If it isn't centered straight away from the sprocket and is pointed up too much, that makes derailures easier. I'd assume the 8t sprocket is for 1/4 pitch chain. Spikes are handy for one handing or burying longer bars especially when the tip doesn't reach through. Many little saws aren't strong enough to be leaned on much at all, but it can relieve stress on your wrist. You probably could have just bought an even cheaper clutch spring to try out instead of a new clutch. As for getting it warmed up, or for cold starts: either keep it tuned on the rich side, especially the low speed needle, or simply let it fast idle on half choke for 10-30 seconds. I always start my 2511t on 2/3 choke, it starts in fewer pulls for one, and if it is cold I can let it run like that a bit to warm up.

 

[Cerberus]

Why would you want the bar angled up? If it isn't centered straight away from the sprocket and is pointed up too much, that makes derailures easier. I'd assume the 8t sprocket is for 1/4 pitch chain. Spikes are handy for one handing or burying longer bars especially when the tip doesn't reach through. Many little saws aren't strong enough to be leaned on much at all, but it can relieve stress on your wrist. You probably could have just bought an even cheaper clutch spring to try out instead of a new clutch. As for getting it warmed up, or for cold starts: either keep it tuned on the rich side, especially the low speed needle, or simply let it fast idle on half choke for 10-30 seconds. I always start my 2511t on 2/3 choke, it starts in fewer pulls for one, and if it is cold I can let it run like that a bit to warm up.

Clutch springs were 3-packs, for more-than the price of the clutch (which comes with 2 springs!)

Re bar angle.. Steeper bar angle relative to the grip (to a degree, of course) allows more precision. Leaving-aside your left-handlebars for a second, and considering saws when held not when they're on a flat surface, your key 'positions' are the grip, and its spacing from the bar (in vertical and horizontal planes), and the relative angle of the b&c to the grip. I see it in my 3 climbsaws, each bigger one (from 25cc, 32cc, to 36cc) each one's angle is less steep than the one before.
The steeper angle, with 10" and 12" b&c setups, just feels better / more precise (am speaking of in-tree work, and will say it is far more noticeable for "top of bar" cutting for instance if you're making a notch on the far-side of a branch using the top of your bar, this type of steep setup lets you 'get in there' w/o having to reach around nearly as much, and for bottom-of-bar I wouldn't say it's of much benefit but it's not a detriment and I do prefer it. Wasn't so desirable when I had a 16" b&c on it, felt kinda unwieldy, so to me it makes sense (and is desirable) that all my saws 'fall in line' that way, actually the other main aspect of 'saw-to-you' position, the left-handlebar, is also more aggressive on each of my units the smaller they are, IE the 355t has a much more vertical left-handlebar that kinda forces you behind the bar more, compared to my g2500-clone (or even to their 2511t which has a more aggressive left-handlebar angle than mine)
I will say this does depend entirely on the types of cutting too, but with the steeper angling I can still "back off" from it a bit easier than it is to 'lean into' a saw that's got a much greater bar-angle and much more vertical handlebar (I imagine there's a pretty neatly linear correlation between these factors and the precision someone has w/ any given saw, and also with how dangerous the saw is IE likelihood of injury and severity :/ )

Re wrists, dogs.... I dunno I still have never found my dogs useful on any saw I own including rear handles :/ Wrists though...Have you held the 355t with the rear-of-palm grip? It's a game-changer IMO, I wish it were more widely adopted (and it sucks it's on my big saw, which I can't really 1-hand anyway, though it's still great for 2-hand use) That type of palm grip/padding reallllly lets you exert control when 1-handing, have been meaning to fiberglass one for ^this thread's saw actually

Thanks for tips Re carb, what would you've started the H&L's on, and how would you have started the Idle, when you knew that Idle could be off by multiple turns? I was literally just figuring the Idle's increased fuel was 'covering me' for improper H&L, not realizing the clutch spring missing caused that engagement, and unlike H&L I can't just bottom-out & start-over w/ my Idle, I've no f'ing clue where it should be :/

I can't get a 2/3rd choke on my 355 I swore it had same levering as 2511 guess now Thanks again for tips especially the 10-30s fast idle, got a new chain&plug in him and about to go do my 2nd session trying to get him running properly so he can re-enter the lineup Sucks w/o him he's so small!!!

 

[Cerberus]

And yeah the 8t is for stihl setups / 1/4" pitch, which I think is superior for sure but I've got a ton of chains for every size climbsaw all in 3/8LP (one 18" in 3/8) so don't see it as wise to leave that setup (would need new files and crap too...then watch the thing fail a week later, and echo releases a 60V top-handle & I lose interest in small petrol climbsaws entirely That time is coming soon, some of the climbers I look up to most have embraced Husqy's top-tier unit, blows my mind a 40V can perform they were such dog-*s-word when they first came out but apparently got a lot better....planning to hold out for a good 60V eco-system, polesaw/climbsaw/blower )

 

[FergusonTO35]

You like these saws alot, so how about get a fleet of them going?

 

[Nutball]

You can bottom out an idle speed screw, just watch for when the throttle plate closes completely, then increase from there. You want it as closed as possible to avoid getting interference from the mid range jets. Then use the L screw to make the idle and transition reliable.

I think 2/3 choke should be possible on a 355t: set the choke on, then you should be able to back the switch off a little without touching the trigger.

 

[Cerberus]

You like these saws alot, so how about get a fleet of them going?

Joke > my head.... sorry don't get it BUT, if I did have a fleet, I would most certainly get them if the fleet-economics were the same as solo-proprietorship economics (I know Stihl/etc must have some fleet deals & benefits no?)

But yeah at $100-150, shipped & ready to rock, I'm in love with it and still use it as my default. Sole problem was the clutch-spring which *I* caused, and - thanks to this platform's parts-availability - I paid $11 and had my new clutch in a week (was cheaper than buying a pack of springs ) and it's been a champ ever since.

You can bottom out an idle speed screw, just watch for when the throttle plate closes completely, then increase from there. You want it as closed as possible to avoid getting interference from the mid range jets. Then use the L screw to make the idle and transition reliable.

I think 2/3 choke should be possible on a 355t: set the choke on, then you should be able to back the switch off a little without touching the trigger.

Thanks I'd never thought to 'feather' the choker-lever, when I feel knobs of that type that have positive stops I always figure they're "discrete" or "a/b" things and forget they're often continuous/variable-control on parts of this sort, will try tomorrow or next day I fire it up as I only turn it on for maybe ~1/3rd of my jobs right now (just getting on Angie's list so hopefully removals, not limbing, can become the norm when I find gigs ;D )