carboned up?how do i prevent that?
The Stihl 362 disappointment
- Thread starter bluchz
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With less oil in the combustion chamber. Either bad mix ratio or rich high needle is your problem. Both would foul a plug like that.
windthrown
361 Junkie
Agreed on the oil, but a US saw with limiter tabs is nearly impossible to tune too rich (w/o cutting the limiter tabs). Though he could have not cleaned his air filter and run it rich for lack of air, or more likely from muffler screen buildup. Could have also run with generic/marine type oil, or old style dyno FB grade oil. Use a good 100% synthetic oil and you will not have carbon buildup from the oil on the piston or the muffler screens (even running 40:1). I run at 45:1 myself... no carbon on any of my saws, blowers or trimmers running Elf 100% synthetic FC grade oil and premium E0 gas, tuned slightly fat with the limiter tabs trimmed...
Standard Stihl warranty here was 1 year for home use, and 6 months for pro use. Now its dropped to 1 year home owner and 3 months pro. Certain times of the year they will add a second year warranty coverage for new homeowner purchases. I have NEVER had to take any saw that I bought new (either Husky or Stihl) back for warranty work though. Note also that the Stihl saw warranty is not transferable to a second owner of a saw... many sell them on CL here as 'still under warranty'. However the Stihl warranty is useless if you did not buy the saw new.
GrassGuerilla
Olympic Piss-reving wanna be.
Ok, thinking proactive here. Do you have any running saws? I'd advise you to pull maintenance on them and inspect the plug and tune accordingly.
I'm thinking a lot of your issue could be solved with a small slotted screwdriver and fresh mix with a known, consistent quantity of oil.
As brad suggested, M Tronic would be good for your needs.
I'm thinking a lot of your issue could be solved with a small slotted screwdriver and fresh mix with a known, consistent quantity of oil.
As brad suggested, M Tronic would be good for your needs.
sunfish
Fish Head
MTronic yes, if they can get the mix ratio somewhat close to 40-50:1
I don't think M-Tronic is going to solve anything if someone doesn't take mixing fuel seriously.
How often are the air filters cleaned? This will cause a too-rich condition.
How much are the saws idled? If it's a lot, this can lead to carbon build up.
The first plug is hard to see, but it looks a little oily. Too much oil in the fuel can cause issues too, depending on your use.
How often are the air filters cleaned? This will cause a too-rich condition.
How much are the saws idled? If it's a lot, this can lead to carbon build up.
The first plug is hard to see, but it looks a little oily. Too much oil in the fuel can cause issues too, depending on your use.
Is there not someone on your crew...preferably you, that can mix the fuel? Create some consistency.
It's understandable (but not acceptable) that your employees don't know or don't care. I'm in the same boat everyday with our fleet and tools. I find that I have to take away as much thinking duty as possible and just allow them to do their job, no more no less. Sounds like micro managing until you think of it as self preservation.
Case in point. We sell lawn mowers and when the big switch from 2stroke to 4 stroke came out over a decade ago, it was very very common for people to bring back their blown 4 stroke claiming the "I told you it wasn't any good compared to my 1976 lawn boy " excuse. But to dig to the route of the problem the public simply couldn't figure out the oil issue. The bottle that came with every 4 stroke lawn mower rarely made it into the crankcase, and sometimes it was even mixed with the fuel. The solution to our problem was simple(not immediate I'll admit but simple) PUT THE 4 STROKE OIL IN THE LAWN MOWER BEFORE THE MOWER LEAVES THE FLOOR. Why educate everyone?? most won't get it. Mix your own fuel and learn to tune and you'll save thousands. Probably yearly.
It's understandable (but not acceptable) that your employees don't know or don't care. I'm in the same boat everyday with our fleet and tools. I find that I have to take away as much thinking duty as possible and just allow them to do their job, no more no less. Sounds like micro managing until you think of it as self preservation.
Case in point. We sell lawn mowers and when the big switch from 2stroke to 4 stroke came out over a decade ago, it was very very common for people to bring back their blown 4 stroke claiming the "I told you it wasn't any good compared to my 1976 lawn boy " excuse. But to dig to the route of the problem the public simply couldn't figure out the oil issue. The bottle that came with every 4 stroke lawn mower rarely made it into the crankcase, and sometimes it was even mixed with the fuel. The solution to our problem was simple(not immediate I'll admit but simple) PUT THE 4 STROKE OIL IN THE LAWN MOWER BEFORE THE MOWER LEAVES THE FLOOR. Why educate everyone?? most won't get it. Mix your own fuel and learn to tune and you'll save thousands. Probably yearly.
SawTroll
Information Collector
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SawTroll
Information Collector
Of course it won't - that isn't what it is designed for.
066blaster
Addicted to ArboristSite
i thought it has been said on here to use between 32-40:1 do we really think they have been using more than that. the muffler screens look dry and rather clean.
wondering how many hours they are putting on their saws. 30 hrs a week?? times 24 weeks = 720 hrs how many hours would one expect to get out of a saw.
i think they should sell them every six months, and get new ones. or inspect and or rebuild the top end if needed. and the saws would last even less time if the oil mix was lean or the carb was set lean,,,, if i owned the company i would set em rich and mix the oil rich too!!!!
wondering how many hours they are putting on their saws. 30 hrs a week?? times 24 weeks = 720 hrs how many hours would one expect to get out of a saw.
i think they should sell them every six months, and get new ones. or inspect and or rebuild the top end if needed. and the saws would last even less time if the oil mix was lean or the carb was set lean,,,, if i owned the company i would set em rich and mix the oil rich too!!!!
Post #19 almost leads me to believe fuel is being mixed in the saw and this would explain everything.
John
John
066blaster
Addicted to ArboristSite
Or... the amount of oil required for 5 Gals is being mixed in whatever size jerry can is available. I mean I could tell you right now if I told one of my junior staff to mix 2 OZ in a full jerry can, they wouldn't hesitate to mix 2 oz in any sized jerry can. 5 gal or 2.5 gal. Because I only specified the 2 Oz. Point being if they don't understand the point of mixing oil then its all the same to them anyway.
Too many variables to let your staff handle if you expect consistency.
When I was in charge of large amounts of saws, I would mix as much as we needed for a week in 5 gallon cans. I then filled one gallon cans for the crews from these 5 gallon master cans. On big jobs I might have had three 5 gallon jugs going every day. On small jobs it would just be one. At no point did anyone try and estimate how much fuel was left in a fiver and estimate how much oil it needed. ONLY empty fivers were allowed to be refilled and oil added.
Giles
ArboristSite Operative
I have run two cycle engines for over 50 years, and I have never had a carbon problem, to your extent. I am not saying they won't carbon up, just saying there must be a solution to your carbon buildup.
As stated, carb tune is critical along with correct oil/fuel mixture.
Could your problem possibly be related to extended idling? That will carbon an engine nearly as fast as lugging (not operating with maximum throttle).
Example---I bought a new Husqvarna 40 chainsaw in 1980?? I have no idea how many hours are on the saw but it has MANY!!! and I have never been inside this saw, other then carb work!
Here is -- not so good-- photos of exhaust and sparkplug.---
As stated, carb tune is critical along with correct oil/fuel mixture.
Could your problem possibly be related to extended idling? That will carbon an engine nearly as fast as lugging (not operating with maximum throttle).
Example---I bought a new Husqvarna 40 chainsaw in 1980?? I have no idea how many hours are on the saw but it has MANY!!! and I have never been inside this saw, other then carb work!
Here is -- not so good-- photos of exhaust and sparkplug.---
I've had a 362 and 461 come back that had completely closed up their exhaust screens within a couple tanks of brand new. I questioned both customers pretty thoroughly. The 362 was clogged up from 1/3 throttle running for hours on end with very little load cutting details in log work. The 462 was run at 1/2 throttle for about 5 cords of 6" and smaller spruce log scraps for firewood. In the old days, that was a good way to burn up a saw because the older carbs didn't have much fuel in the mid range. It is my understanding that modern carbs make up for this with copious amounts of fuel in the midrange. Carburetors are my weak point when it comes to saws, so I'm not 100% sure. What I have seen, though, with really carboned up saws is long idling or low running speeds.
OK KenJaxTree,
I would be curious to know how many hours are actually on this particular MS 362. Figure an average limb of about 8", about 10 sec per cut, 720 assumed hours, that saw should have made about 259,200 cuts. I'll never know how fellers figger they can receive "thousands of hours" from a chainsaw, maybe if thousands of those hours are spent skidding, splitting, rigging, carrying, and travel time. But alas, the 562 is not off the flimsy list because of this story...
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I never claimed to be a saw mechanic, so I don't have a very sure diagnosis for this particular problem. But I do know that carbon forms rapidly from 2 cycle oil sticking to hot surfaces (coking). Likely more than one operating parameter was out of whack that allowed the saw to cook. Any engine can be destroyed, but Husqys are still flimsy.
066blaster
Addicted to ArboristSite
well a saw is not always in a cut while running, and not sure if this guy is logging, tree service, or firewood guy. and for business use the saw has a purpose,,to get the job done, they get scratched,dented, run over, slid around in the back of a truck, dropped, and neglected, just like the people using them....A saw will often resemble the person using it... Do you wear a suit and tie to work?
Are you sure the saws aren't being burnt up running with dull chains?
