029/290 Problem, Stalls At Idle, Suggestions Anyone - StihlTech??

[manstihl]

I own 3 029/290 Stihls saws and use them on my farm. The first 029 I purchased (about 5 year ago) is giving me a problem, it stalls at idle, and sometimes even while running at lower speeds, it "feels like" it is just running out of fuel, or like the off switch was flipped. I have replaced the fuel line, fuel filter, spark plug, cleaned everything up, put a carb kit in it, 2 of them in fact, it still does this. The other day I pulled the carb limit stops off and reset the carb using the open one turn open from full closed, then tune, I had the saw running great, I thought I fixed the problem, then it started doing this again. I think there is some sort of air leak somewhere, possibly seals which effect the "pulse", I have not replaced the pulse line, not yet anyway. When the saw is at idle you can tell it is going to stall because it speeds up a little bit, then it stalls like someone shut off the gas. If the saw speeds up at idle is it going rich (getting more fuel) or going lean (getting more air)? If it is going lean when it speeds up at idle then I assume this means some sort of air leak? If it is going rich when it speeds up at idle then I have no idea what the problem is. I thought it was carb, but evidently not. I have not put a brand new carb on it, just OHed the existing one. This saw has quite a few hours on it and does not owe me a dime, but I would like to keep it working. When the saw dies at idle you usually (note I said "usually") can not start it up again, but if you let it set for an hour then it starts right up. Another 290 saw that I had purchased new started doing this exact same thing not long after I bought it, same thing, like it was running out of fuel, I junked that one out for parts as I needed some parts off it and since it was the worse running saw of the 3 I junked it, never did find out what the problem was with that saw. Lastly, when the problem saw speeds up and starts to stall at idle you can sometimes bring it out of this condition by pulling the throttle trigger (give it full throttle) and that usually corrects the situation for a time and it will then go ahead and idle again, but the saw will usually stall at idle if you warm it up. Sometimes it stalls, sometimes it doesn't, usually it does, but if you use it enough and get it warmed up it will start doing this sooner or later. I have adjusted the carb screws until I am blue in the face, I don't think it is a carb adjustment. I think there is an air leak, or fuel leak somewhere, or the carb is bad. I have not taken it to the dealer for the vacume test or whatever you call it, I figured that if I have to take it to the dealer and pay them it will not be worth fixing. I shouldn't complain, I have got aheck of a lot of use out of this saw over about 5 years time, but the saw runs great when it runs and I would love to keep it around. Anyone? Very likely the key to this is the fact that at idle the saw will "speed up" a little bit, then stall like the fuel was shut off (or I assume the fuel mixture went wrong). I think this condition is exactly what happens if the saw would actually run out of gas while at idle, I guess that means it is going lean? Again, this saw has a lot of use hours on it, but as noted I had one other saw a 290 that did the same thing and I junked that one out.

P. S. If it is seals is this something that I could do myself? I have had the clutch off doing service on the clutch and I am pretty sure you can see the seal on that side right under the clutch area, there is a similar seal under the flywheel, right? Anyone?

Mitch

 

[Lakeside53]

It sure sounds like seals, or a flaky impulse line. The ONLY way to tell is to pressure and vacuum test the saw. You'll know in 10 minutes exactly where you problem is, or where it it not.

With a little care you can do the seals yourself. You really need a seal puller, but a few other techniques can work. There are TWO DIFFERENT seals - one type if you take the engine pan off, and the other if you do not. Make sure you get the correct type.

I wouldn't bother with seals unless you vacuum test the saw. It's uncommon for seals to go out on an 029 unless the bearings are bad, and much more likely to have a bad or poorly fitting impulse line.

 

[stihltech]

redneck air test

Do this little test and you will know if the pulse line is OK.
Get a can of carb or brake cleaner and put the nozzle down beteen the tank housing and cylinder. Give it a spray. I the idle changes , usually drastically, you probably are not working on commission, oops, I mean , you have a bad pulse hose.
This is not a good way to check the seals.:taped:

 

[hboy43]

Hi:

I don't know anything but ... any chance you took a problem part from the junked machine and transplanted it into other machine. Seems kind of strange that both machines had the same unknown problem.

hboy43

 

[manstihl]

Thanks to those who replied. First, did not take any parts off the junked machine, not a part that would effect this problem or cause this problem. To stihltech, thanks for the suggestion on redneck pulse line check, I will try that, I also purchased a new pulse line as it was only $4.00, if I can only install it??? The local stihl dealer mechanic says he can run the preasure/vac test and it will only cost me the minimum charge if the carb and muffler are removed first (that I can do), so if the new pulse line does not fix this I will probably have that test done as suggested. The stihl dealer said that since the speed of the saw increases before it stalls this means it is going "lean", meaning, I assume, getting more air. This must mean a leak somewhere. The stihl dealer also says he has seal pullers, and if the clutch and flywheel is off I assume that would be a quick replacement job. I hate to put a lot of money in this old saw, but when it runs it screams, the only problem with it is this stall at idle. Thanks again to all that replied.

 

[Lakeside53]

Good to see you have a dealer that will work with you!

 

[Fish]

Take the carb apart again, and remove the needle/spring and the screen
from the pump side, and hold the carb up to a light to visually verify that
the passage is fully cleaned, I am guessing it is not.

 

[stingray bay]

I own 3 029/290 Stihls saws and use them on my farm. The first 029 I purchased (about 5 year ago) is giving me a problem, it stalls at idle, and sometimes even while running at lower speeds, it "feels like" it is just running out of fuel, or like the off switch was flipped. I have replaced the fuel line, fuel filter, spark plug, cleaned everything up, put a carb kit in it, 2 of them in fact, it still does this. The other day I pulled the carb limit stops off and reset the carb using the open one turn open from full closed, then tune, I had the saw running great, I thought I fixed the problem, then it started doing this again. I think there is some sort of air leak somewhere, possibly seals which effect the "pulse", I have not replaced the pulse line, not yet anyway. When the saw is at idle you can tell it is going to stall because it speeds up a little bit, then it stalls like someone shut off the gas. If the saw speeds up at idle is it going rich (getting more fuel) or going lean (getting more air)? If it is going lean when it speeds up at idle then I assume this means some sort of air leak? If it is going rich when it speeds up at idle then I have no idea what the problem is. I thought it was carb, but evidently not. I have not put a brand new carb on it, just OHed the existing one. This saw has quite a few hours on it and does not owe me a dime, but I would like to keep it working. When the saw dies at idle you usually (note I said "usually") can not start it up again, but if you let it set for an hour then it starts right up. Another 290 saw that I had purchased new started doing this exact same thing not long after I bought it, same thing, like it was running out of fuel, I junked that one out for parts as I needed some parts off it and since it was the worse running saw of the 3 I junked it, never did find out what the problem was with that saw. Lastly, when the problem saw speeds up and starts to stall at idle you can sometimes bring it out of this condition by pulling the throttle trigger (give it full throttle) and that usually corrects the situation for a time and it will then go ahead and idle again, but the saw will usually stall at idle if you warm it up. Sometimes it stalls, sometimes it doesn't, usually it does, but if you use it enough and get it warmed up it will start doing this sooner or later. I have adjusted the carb screws until I am blue in the face, I don't think it is a carb adjustment. I think there is an air leak, or fuel leak somewhere, or the carb is bad. I have not taken it to the dealer for the vacume test or whatever you call it, I figured that if I have to take it to the dealer and pay them it will not be worth fixing. I shouldn't complain, I have got aheck of a lot of use out of this saw over about 5 years time, but the saw runs great when it runs and I would love to keep it around. Anyone? Very likely the key to this is the fact that at idle the saw will "speed up" a little bit, then stall like the fuel was shut off (or I assume the fuel mixture went wrong). I think this condition is exactly what happens if the saw would actually run out of gas while at idle, I guess that means it is going lean? Again, this saw has a lot of use hours on it, but as noted I had one other saw a 290 that did the same thing and I junked that one out.

P. S. If it is seals is this something that I could do myself? I have had the clutch off doing service on the clutch and I am pretty sure you can see the seal on that side right under the clutch area, there is a similar seal under the flywheel, right? Anyone?

Mitch

Hi I had the same problem with my 029, eventually it started leaking petrol from the tank causing me to finally do something about it. All it was was the rubber fuel supply hose from the pickup in the tank, that goes through a grommet to the carb. It had perished/split between the grommet and the carb, sometimes letting in air and sometime letting out petrol (normally when it was switched off, on its side to be refilled). 10 minutes and a new hose (cheap) it was all fixed, I hope yours ends up being as simple.

regards

Mark

 

[Lakeside53]

Hi I had the same problem with my 029, eventually it started leaking petrol from the tank causing me to finally do something about it. All it was was the rubber fuel supply hose from the pickup in the tank, that goes through a grommet to the carb. It had perished/split between the grommet and the carb, sometimes letting in air and sometime letting out petrol (normally when it was switched off, on its side to be refilled). 10 minutes and a new hose (cheap) it was all fixed, I hope yours ends up being as simple.

regards

Mark

Very common - it perishes that that point because sunlight gets in under the carb box,

 

[stingray bay]

MS880 decompression valve resetting before starting

Very common - it perishes that that point because sunlight gets in under the carb box,

Hi lakeside53 I'm not sure if I should start a new thread as this is my second posting! I searched on everything 880 without coming across this one, but I note that you have a 088 and wondered if you have ever come across this one before. I just bought a brand new Stihl MS880 so its never touched wood. Trouble is it a real b@$! to start. What happens is that the decompression valve pops out when you are pulling it over, ripping the grip out of your fingers. There is no sign of combustion (sound or smoke), It normally happens 1st or second pull, without warning, but not every time (I can start it sometimes). Am I doing something wrong? (like puling it over fast enough to trip the valve, or is this problem due to a new/tight motor having too much compression (enough to close the valve), or some other fault? I've asked Stihl to come back to me but your comments would be appreciated before I lose my fingers.

Regards

Mark

 

[Lakeside53]

Hi lakeside53 I'm not sure if I should start a new thread as this is my second posting! I searched on everything 880 without coming across this one, but I note that you have a 088 and wondered if you have ever come across this one before. I just bought a brand new Stihl MS880 so its never touched wood. Trouble is it a real b@$! to start. What happens is that the decompression valve pops out when you are pulling it over, ripping the grip out of your fingers. There is no sign of combustion (sound or smoke), It normally happens 1st or second pull, without warning, but not every time (I can start it sometimes). Am I doing something wrong? (like puling it over fast enough to trip the valve, or is this problem due to a new/tight motor having too much compression (enough to close the valve), or some other fault? I've asked Stihl to come back to me but your comments would be appreciated before I lose my fingers.

Regards

Mark

Hmmmm, not sure...

Pull it over slowly until you feel the compression stoke, then pull quickly and smoothly. if you pull it over at at any random point, it will fire, but just snap the valve and you hand. Mine bites me now and then.

 

[MotorSeven]

I have to reset the de-comp button after each unsucessfull yank on the 066...thought it is normal>

 

[Lakeside53]

I have to reset the de-comp button after each unsucessfull yank on the 066...thought it is normal>

Depends... My 066 will pop the decomp occasionally when it turns over, but generally not unless it fires. I do crank it over until I feel the compression stroke coming though . Sometime it's hard to detect the "fire" ...
The decomp has a ball bearing and spring that locks into a detent. If the shoulders on the detent get worn, it's easier for the decomp to pop.

 

[stingray bay]

Depends... My 066 will pop the decomp occasionally when it turns over, but generally not unless it fires. I do crank it over until I feel the compression stroke coming though . Sometime it's hard to detect the "fire" ...
The decomp has a ball bearing and spring that locks into a detent. If the shoulders on the detent get worn, it's easier for the decomp to pop.

Thats good advice re the compression stroke, that would definitely help and I will try it tomorrow (as it possible it wasn't quite right). I think I have it sussed, More gorrilla required (than my 6'1" 215lb frame)! I checked the valve by removing the plug and screwing my compression tester in instead. The valve would not close no matter how many times you pulled in over at whatever speed (psi = 110) so it was definitely combustion that was closing it. So then I closed the valve and tested it again - a shade under 150 psi. I tried starting it with two hands, foot on saw (cold) started second pull. I warmed it up and could start it first pull with one hand (warm). I think the kick that was pulling it out of my (one) hand was the stroke it needed to start, hence two hands was enough to overcome it. But boy smaller people must really struggle to start this baby. You'd definitely give up quickly if you had a fouled plug etc. On a positive note it really rips through a practice log we are slabbing (40" dia 8' long cupressus macrocarpa log) before we try on some big stuff


Regards

Mark

 

[Lakeside53]

Thats good advice re the compression stroke, that would definitely help and I will try it tomorrow (as it possible it wasn't quite right). I think I have it sussed, More gorrilla required (than my 6'1" 215lb frame)! I checked the valve by removing the plug and screwing my compression tester in instead. The valve would not close no matter how many times you pulled in over at whatever speed (psi = 110) so it was definitely combustion that was closing it. So then I closed the valve and tested it again - a shade under 150 psi. I tried starting it with two hands, foot on saw (cold) started second pull. I warmed it up and could start it first pull with one hand (warm). I think the kick that was pulling it out of my (one) hand was the stroke it needed to start, hence two hands was enough to overcome it. But boy smaller people must really struggle to start this baby. You'd definitely give up quickly if you had a fouled plug etc. On a positive note it really rips through a practice log we are slabbing (40" dia 8' long cupressus macrocarpa log) before we try on some big stuff


Regards

Mark

I assume you have an elastostart on the saw? Really makes a difference... I'm with you on the fouled plug... If I miss my start, it's a pain to get restarted if hot, in the wood and on the mill! I run it real rich and lots of oil, so fouled plugs and easy flooding are the norm... I just wait a couple of minutes,then hold open the throttle and pull like crazy, with the decomp OUT.

When it's not on the mill, has normal gas mix and is retuned, no problems if I wind it to the compression stroke.

 

[jack-the-ripper]

Stingray- 880 start

There was a recent post about starting the 660. Method is as follows. Decompression on, put the choke on and made 2 slow pulls. Then put it back to the half choke/fast idle position, with decompression on. 1 pull and my 660 took off like a bat out of you know what! I will definitely continue to use this method as it works beautifully. Hope it works on your 880.

 

[stingray bay]

Priming with a couple of slow pulls does seem to help, but it does not start unless it is pulled over quicky with the choke on full (cold), then started on fast idle (Std Stihl starting procedure). Ensuring the piston is in the right part of the compression stroke definitely helps. I do have an elastostart but I have found that using two hands to avoid any chance of the saw winning on a kick back is the way to go. As before, I can generaly start it first pull with one hand when warm without being bitten. Thanks for all your help, this is an awesome site full of great tips. Regards Mark

PS I am interested in what mix you run when milling Lakeside 53 as the local stihl agent (after consulting sthil NZ) recomended the std 50:1 and also how rich you run the saw (more or less than the run in setting)

 

[Lakeside53]

PS I am interested in what mix you run when milling Lakeside 53 as the local stihl agent (after consulting sthil NZ) recomended the std 50:1 and also how rich you run the saw (more or less than the run in setting)

For milling I run around 40:1 semi-synthetic (Stihl's "low smoke"), but it varies lower depending on how much mix is in the can to start with. I'm moving to 32:1, full synthetic. In Stihl lingo that means their "Ultra" oil, or you might have the mobile M2XT available.

If Stihl NZ is going to recommend 50:1, ask them (in writing) if the warranty will be valid when milling. You'll either get a deafening silence or a "no". On the ratio they are caught between corporate policy and the emission requirements. As to milling in big wood, it's the hardest work a saw can ever do - full power for the entire tank.

In addition to mix, it's most important to retune the saw H so it runs really rich.. set the H WOT to about 10.5k, or less... It's hard to do accuratly on an 880 as there is a rev limiter in the coil (I think?), so be careful and err on the rich side... In any case you'll need to remove the limiter cap and slice of the tab. Makes it much easier to reset the H when using the saw conventionally.

 

[stingray bay]

If Stihl NZ is going to recommend 50:1, ask them (in writing) if the warranty will be valid when milling. You'll either get a deafening silence or a "no". On the ratio they are caught between corporate policy and the emission requirements. As to milling in big wood, it's the hardest work a saw can ever do - full power for the entire tank.

That excellent advice, I will ask them to forward me their recommendation for warranty cover in writing. It is interesting as there is no (as far as I know) chainsaw emission restrictions in NZ (too many farmers, not enough chainsaws - but the saw probably comes in with std American settings anyway). They have set the saw up really rich for the run in period but said they would reset it next time I take the saw to town. I do have a digital tachometer and could easily tune the H setting accurately to below 10.5k WOT with that, I do have one question is the speed on chainsaws set with the chain and side cover on or off (I do my scrub saws directly off the blade, but it would be easier to do it on the chainsaw off the flywheel).

 

[stingray bay]

I spoke to the Local Stihl agent again today, he said the Stihl warranty book used to have exclusions for milling but no longer mentions it. He said the book states you must use 50:1 for Stihl oil and 25:1 for ALL others. I have asked him to get the warranty mix (ie 50:1) specifically for milling in writing from Stihl NZ. I will keep you posted with what they come back with. They also told me they have removed the emission limit stops as a matter of course (I didn't think they worried about emissions in NZ). Regards Mark