Makes sense. If you don't lube the clutch bearing every day, the harder bearing will wear the softer crank.
stihl 261 and 362 crank problems
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nitehawk55
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Yes , doing that is really hard on the bearings , drum and crank . I rebuilt 2 of them and are still in use by a private fellow who runs a tree service and looks after his saws . The crank surface where the drum bearing runs is rounded some and a bit loose but becomes a moot point once the clutch locks the drum anyway .
Ford150 , I'd be pretty sure something is up with these failures with this crew , Stihl would be on top of that pretty quick if it was a QC issue and there has been no large numbers of failures like you're seeing . Does Stihl screw the pooch sometimes ? , yes they do (no one company is perfect) and as far as the M-tronic and Husky A-T systems time will tell with that . I think running a good oil at 40:1 is good insurance just in case the settings go off a bit from ideal . This happened with old school saws too because of different conditions the saws were run in . Lots of variables effect 2 stroke engines and it doesn't spell out too clearly sometimes .
Ford150 , I'd be pretty sure something is up with these failures with this crew , Stihl would be on top of that pretty quick if it was a QC issue and there has been no large numbers of failures like you're seeing . Does Stihl screw the pooch sometimes ? , yes they do (no one company is perfect) and as far as the M-tronic and Husky A-T systems time will tell with that . I think running a good oil at 40:1 is good insurance just in case the settings go off a bit from ideal . This happened with old school saws too because of different conditions the saws were run in . Lots of variables effect 2 stroke engines and it doesn't spell out too clearly sometimes .
that makes sense. hadnt thought of them doing that and the long term affects. i just couldnt come up with a any reason for the crank failures at the clutch bearing. i am going to chalk this one up as solved with your explanation.
big end rod bearing failures occur from over speeding for prolonged periods...im sure these crews do that cutting brush with a saw which is why i tried setting the saws richer to keep the revs under 13k. never found out if that help since they could tell it wasnt turning the same rpms and attempted to tune it themselves. mtronic saws coming in roasted with good mix in the tank could be straight gas the previous tank/tanks and just happened to fail completely on a tank of good mix. but i am curious how much a bad solenoid affects high speed performance and if i am seeing the affects of prolonged running with bad solenoids. they change those themselves when they get tired of dealing with the throttle blipping.
now does anyone have good info about that solenoid and the mtronic software? is it worth a non stihl dealer buying it or am i wasting my money?
Justsaws
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Setting the brake every time I move is standard behavior on the hills or in a pile. I am not a commercial user but I am typically more than willing to "abuse" a saw, lately Stihl 018, Husq 350 and 365. I do not wait for the saw to return to idle, the saw can either measure up or fall short.
In less than a year one mechanic I knew replaced over 25 1127 P/C s for an easement crew, the pistons and sometimes cylinders were just worn out.
Not mechanically damaged, just worn out. Same mechanic did a lot of damage repair as well but the main drawback to the 1127s was how the pistons would wear. Clutch drums and mufflers burning through were also fairly common. The 390s with 24" bars would wear through the tubs next the anti vibe mounts, not yanked out worn through.
That particular group had a lot ground crew and they were working. They also got a fairly good deal on the saws and parts.
361s burnt through mufflers, p/Cs and clutch drums as well, they did not toss flywheels, cranks and generally fall apart like the early 391 and 362s. I have not seen any of the 261s other than on the display shelf or repair bench. They were not out when I was actively looking for information.
The 211s were also largely considered to be junk as well, they simply fell apart.
In less than a year one mechanic I knew replaced over 25 1127 P/C s for an easement crew, the pistons and sometimes cylinders were just worn out.
Not mechanically damaged, just worn out. Same mechanic did a lot of damage repair as well but the main drawback to the 1127s was how the pistons would wear. Clutch drums and mufflers burning through were also fairly common. The 390s with 24" bars would wear through the tubs next the anti vibe mounts, not yanked out worn through.
That particular group had a lot ground crew and they were working. They also got a fairly good deal on the saws and parts.
361s burnt through mufflers, p/Cs and clutch drums as well, they did not toss flywheels, cranks and generally fall apart like the early 391 and 362s. I have not seen any of the 261s other than on the display shelf or repair bench. They were not out when I was actively looking for information.
The 211s were also largely considered to be junk as well, they simply fell apart.
nitehawk55
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I should have added that tightening the chain too much is also hard on the clutch drum and crank bearings but I think that's commonly known but the use of the brake coming out of a cut is really hard on them .
You could be on to something there I seen guys tighten stuff to the point where it drops rpms.
Good point, if they are doing extensive brush cutting, they may over tighten that chain so they don't loose it. A loose chain will often come off when brush cutting.
There is likely some type of abuse going on here, and it could be a combination of chain break, over tighten, dull chain, etc. It will all add up. They may even be forgetting to take the break off before hitting the throttle.
There is likely some type of abuse going on here, and it could be a combination of chain break, over tighten, dull chain, etc. It will all add up. They may even be forgetting to take the break off before hitting the throttle.
I seen a lot of them lean hard on dull chain even to the point where it will just seize up.
Straight gas.
passed pressure and vac. no ethanol in the fuel. fuel in the tank right now looks like it was mixed correctly and it still has half a tank in it. mtronic so it shouldnt have been lean. only thing that leaves is straight gassed. weird thing is usually when they straight gas one....i get 3-6 more to go with it because they all use the same fuel can. this is the only one that was brought in roached that didnt have an air leak. although since i am not aloud to rebuild it im not sure what it was running like.
Is the cyl clogged with dirt and is the chain dull they may have cooked it by leaning on a dull chain in big hardwood.
fins are clean. flywheel/flywheel side of case is clean. air filter is semi clean...really clean for these guys. i never see the bar and chains for the saws. without being able to pull the cylinder to look the piston over better i am stuck on straight gas. i can only look in the ports and dont want to disturb anything to much since it is going back to stihl. I am not sure if it is going back to Stihl or just to a Stihl dealer.
nitehawk55
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It would be good for it to go back to Stihl's Tech dept and let them investigate the cause .
Back in the day of the 046- early MS460 before the carbs became somewhat tamper proof we had loggers from Quebec complaining about their saws seizing (these were the saw of choice) . We had the saws sent to us untouched and did a pressure/vac test to eliminate that as the cause and then did a rebuild . Most often the carb had been leaned out so they were screaming at 15-16K , we knew this because we made a point of not touching the carbs . Saws were returned with a bill and explanation .
You could not get it through these guys heads that a screaming saw did not cut better and the lean seize was not the fault of the saw .
Back in the day of the 046- early MS460 before the carbs became somewhat tamper proof we had loggers from Quebec complaining about their saws seizing (these were the saw of choice) . We had the saws sent to us untouched and did a pressure/vac test to eliminate that as the cause and then did a rebuild . Most often the carb had been leaned out so they were screaming at 15-16K , we knew this because we made a point of not touching the carbs . Saws were returned with a bill and explanation .
You could not get it through these guys heads that a screaming saw did not cut better and the lean seize was not the fault of the saw .
I don't touch the carbs when I rebuild them for that same reason. If limiter is gone they are usually set 1/4 turn lean. Last fall they dropped off half dozen saws all straight gassed by the same crew in one day. Foreman wasn't happy but all I could do was laugh
Too bad you cant go watch how they cut that may solve the issues.
7sleeper
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I have mentioned it before, there was a similar problem here in the german speaking forums with 261's. The guys found out that the greasing of the clutch bearing had been forgotten and that the idling sooner than later wore some markings into the rod with defects emerging. I remember a stihl tech mention that there was a warning sent out by Stihl to regrease the bearings.
7
But these problems seem to be repetitive on various saws, pointing to operator abuse.
Paragon Builder
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Is it possible the mtronic leaned the saw out too much. You were talking earlier that when they fail the idle is screwy but were unsure of how it affected high side. And they keep running them. ???
they keep running them after that solenoid goes bad. For how long....that varies by if they have the parts to fix it and when they get irritated enough to stop and fix it. might be a couple hours all the way to a few days. The ones i have seen that needed the solenoid still had a good piston/cylinder. they were dropped off to repair the throttle linkage and while its here go ahead and put in a new solenoid. I got a little information on the software but still on the fence whether it is worth the money. last year when i asked the dealer about it he quoted me over $400 for it IIRC.
bearings on these saws are greased. im sure they dont grease them when they pull them out of the box new though.
i have watched them on a few occasions. its abusive for sure and allot of the work that is done is not what a chainsaw was designed to do. cutting brush, sticks, brambles are not on the list of things that a chainsaw was designed to cut
