Brand new MS391 meltdown

[ZeroJunk]

Not sure what state your in but I've never bought a new saw from a dealer and witnessed them starting any of them.
Reputable dealers of Stihl, Husqvarna and Echo.
Perhaps it's something the consumer needs to request. ?

The way I took it was buying a new saw and buying a replacement carb.
New saws are set at the factory. Dealer does not get in to it.
Replacement carbs are not set until the mechanic at the store or the owner sets them.

 

[Marley5]

The way I took it was buying a new saw and buying a replacement carb.
New saws are set at the factory. Dealer does not get in to it.
Replacement carbs are not set until the mechanic at the store or the owner sets them.

Ahhh gotcha, my bad.

 

[Old2stroke]

The way I took it was buying a new saw and buying a replacement carb.
New saws are set at the factory. Dealer does not get in to it.
Replacement carbs are not set until the mechanic at the store or the owner sets them.

Something doesn't make any sense. A factory carb setting on a new saw has to be just a nominal setting and can't be correct for all locations, climates and elevations. The limiters give a small range of adjustment to allow for this and is supposed to be done at the local area. When you buy a new saw from a dealer are you getting it in a box with bar and chain that have never been mounted and a dry fuel tank that has never had fuel in it?

 

[Chevboy0167]

I have heard rumor that a test saw gets pulled off the line from every batch/run and gets fueled then ran/tested. Then some settings may get tweaked for the next run/batch. Can't remember from who or where tho.....???

Also, a certain You Tuber has claimed that every saw from one of the big 3 manufacturers gets ran, set and tested. Gospel? I have no idea and don't care. No affiliation with them and I don't believe everything online.

So, lets buy an in box saw, remove spark plug and look down inside the cylinder with a bore scope to search for sings that it has been factory ran.

Donations anybody? (insert sarcasm)





Boy... looks like I need a distraction..... ladies and gentlemen.... Mr. Conway Twitty.......

 

[Vintage Engine Repairs]

Would using 40:1 canned gas cause a leaner low idle if the saw were factory tuned for 50:1? Causing clutch to to engage at low idle with brake engaged?

I have no experience using the wrong fuel mix for the carb tune (yet). My understanding is changing from 50:1 tune to 40:1 requires a richer mixture.

No, changing ratios doesn’t require a change of tune. Going from 50:1 - 40:1 is a 0.5% change. There are other variables that make a far bigger difference.

 

[johnfawn2000]

I purchased a new MS 391. I used it once for no more than an hour. The second time I used it I started it with the chain brake on and let it warm up for two minutes as told by the Stihl Dealer I purchased it from. After two minutes of Idle (chain Brake on) I turned it off and went to start it 5 minutes later. The saw would not crank as the Plastic around the chain brake was melted. The saw was never reved up while warming up. I took it to the Dealer where I purchased it and they acted like I was trying to run it with the brake on which was not the case. I felt it should have been replaced with a new one. Your thoughts please??????

Dear Stumpzero , I worked at Stihl dealership. When a saw d.o.a. or wasn't repairable, the dealership would buy that saw on apply it to new saw. Stumpzero, if you real lucky they may have and old or good shape chainbrake cover for your saw. I am not being a smart aspirin, chalk this up experience .
This one of those things like if I wanna stop my car, I mash the brake pedal , common sense and experience. There are more things to learn about your chainsaw sir, this machine will kill you or disable you with pinches , kickbacks. Then when cut your first tree down , and a big tree and how you cut the tree will with experience as with the chainbrake is now a focus. This means be careful, and have your head or straight. Stump , you might wanna cut with some experience woodmen, I have been cutting for 50 years and have had some close calls where i said thank you GOD.
Stump, you will learn whether it is you or someone else that cuts the tree that there is pressure on those limbs, whether towards or away , from will knock your teeth or brains out. Chainsaws are great pieces of equipment, but are extremely dangerous from the trees and from the saw itself. This can be your friend or disable you. I keep a death grip on my saw and watch and look at the tree limb weight, wind blowing , and learning how to cut a tree and making it go that way comes from experience and working with experienced woodmen , will be a great help and keep you safe. I had to learn and I don't kno it all and never will . Good luck on your chainbrake, this expensive experience, and much experience to come. Be safe Stump , I am not busting your chops just making you aware of what's in front of you.
Thanks Buck

 

[ZeroJunk]

Something doesn't make any sense. A factory carb setting on a new saw has to be just a nominal setting and can't be correct for all locations, climates and elevations. The limiters give a small range of adjustment to allow for this and is supposed to be done at the local area. When you buy a new saw from a dealer are you getting it in a box with bar and chain that have never been mounted and a dry fuel tank that has never had fuel in it?

Every saw I have worked on any time recently had the high needle all the way against the limiter. The idle adjustment had some room. Had to be done at the factory since nobody else has touched. Some saws the only adjustment is turning the low fuel level up to increase or decrease the idle speed. But, not a MS391.
The counter guys start saws for people if they ask, and watch how they do it. Some customers don't want anybody starting it but them.

 

[SteveSr]

Every saw I have worked on any time recently had the high needle all the way against the limiter.

I think that Stihl does this with ALL of their gas engine equipment. All screws (except LA) should be full CCW at sea level. The limiters are designed for leaning the engine for cutting in high temperatures or high elevations when the air is less dense.

 

[Marley5]

I think that Stihl does this with ALL of their gas engine equipment. All screws (except LA) should be full CCW at sea level. The limiters are designed for leaning the engine for cutting in high temperatures or high elevations when the air is less dense.

I've been educated, didn't know this.
Of course the limiters mysteriously left my saws

 

[SteveSr]

I've been educated, didn't know this.
Of course the limiters mysteriously left my saws

Thanks to the EPA you can make the mixture leaner but NOT any richer. I think that Stihl (and other mfrs) had runability issues with their fixed "H" jet carbs from years past so finally settled on the limiter cap "solution" to keep the EPA happy.

 

[Chevboy0167]

How much fuel........? All of it!

 

[stihltech]

Wow, the stuff I hear on this site.
Every saw gets started at this dealership and adjusted if needed. If it does not run right or can't be adjusted, it does not go out the door.
Some new carbs are very close when first installed, but MUST be verified and adjusted.
Yes, the chain must stop at idle with the chainbrake off.

Unfortunately there are some dealers in chain stores that do not even have a tech on site. I know, they are near me.
It just grinds us to think I went to all the training to know how to work on equipment, then the next store does not have to.
There, rant over.

 

[johnfawn2000]

Wow, the stuff I hear on this site.
Every saw gets started at this dealership and adjusted if needed. If it does not run right or can't be adjusted, it does not go out the door.
Some new carbs are very close when first installed, but MUST be verified and adjusted.
Yes, the chain must stop at idle with the chainbrake off.

Unfortunately there are some dealers in chain stores that do not even have a tech on site. I know, they are near me.
It just grinds us to think I went to all the training to know how to work on equipment, then the next store does not have to.
There, rant over.

Dear stihltech , I pickup what your laying down that also goes for
stihl , yellow and green mowers . Buck

 

[ZeroJunk]

Wow, the stuff I hear on this site.
Every saw gets started at this dealership and adjusted if needed. If it does not run right or can't be adjusted, it does not go out the door.
Some new carbs are very close when first installed, but MUST be verified and adjusted.
Yes, the chain must stop at idle with the chainbrake off.

Unfortunately there are some dealers in chain stores that do not even have a tech on site. I know, they are near me.
It just grinds us to think I went to all the training to know how to work on equipment, then the next store does not have to.
There, rant over.

EVERY Stihl saw is ran at the factory in Va Beach. It is connected to an external fuel source, put in an enclosure, and the door shut. The saw idled, revved up, idled revved up for several minutes. Everything is computer monitored. Temp, fuel consumption, emissions, ..
The carb adjustments are made with robotic arms according to whatever the computer says. If the saw passes it is cooled down and put in a box with the limiters fixed where the program says to fix them and shipped out. There is a long row of these test/setup enclosures.
No, we don't start them again unless asked to. There is nothing to adjust.
Obviously, if you are replacing a bad carb with one that the limiters either are not engaged or it never had them it is a different story.

I was curious myself because I have never sold a new saw. I just fix stuff. So, I asked one of our Techs who has done the three day deal at Va Beach.

 

[Old2stroke]

EVERY Stihl saw is ran at the factory in Va Beach. It is connected to an external fuel source, put in an enclosure, and the door shut. The saw idled, revved up, idled revved up for several minutes. Everything is computer monitored. Temp, fuel consumption, emissions, ..
The carb adjustments are made with robotic arms according to whatever the computer says. If the saw passes it is cooled down and put in a box with the limiters fixed where the program says to fix them and shipped out. There is a long row of these test/setup enclosures.
No, we don't start them again unless asked to. There is nothing to adjust.
Obviously, if you are replacing a bad carb with one that the limiters either are not engaged or it never had them it is a different story.

I was curious myself because I have never sold a new saw. I just fix stuff. So, I asked one of our Techs who has done the three day deal at Va Beach.

That’s fine for auto tune but not every destination is the same elevation and climate as Va Beach

 

[StihlsawuserMS361]

Wow, the stuff I hear on this site.
Every saw gets started at this dealership and adjusted if needed. If it does not run right or can't be adjusted, it does not go out the door.
Some new carbs are very close when first installed, but MUST be verified and adjusted.
Yes, the chain must stop at idle with the chainbrake off.

Unfortunately there are some dealers in chain stores that do not even have a tech on site. I know, they are near me.
It just grinds us to think I went to all the training to know how to work on equipment, then the next store does not have to.
There, rant over.

Sounds like where I live. The decent local decent service dealers are gone, we're left with the Hardware Stores / Agway for Stihls. (I'd almost try Husky, but there's not even a dealer anywhere nearby.) Sure, Big Box can sell, forget service. They are good for expendable supplies or ordering parts (if I have the part #), anything else......

 

[pioneerguy600]

The Stihl dealerships I deal with always started every new adjustable carb saw before it went across the counter to the buyer even the later ones with the limiter caps. These dealerships were not the most experienced shops we had here but at least they had a tech to tune a saw. We are located at sea level and they would retune the carbs to the rich side. One of my newest MS440`S had the H limiter pulled and the needle set richer right at the service counter. That dealer tuned rich as a habit to prevent so many lean damaged saws from coming back. I do not know if the new M tronic saw can be set up that way and I am not around the dealerships as much as I was back when all saws had carbs that could be tuned, even the ones with just the L adjustable side along with the LA setting. Set at a reasonable idle so that the chain was not spinning at idle like so many Husqvarna`s were at that time.

 

[drumbum]

EVERY Stihl saw is ran at the factory in Va Beach. It is connected to an external fuel source, put in an enclosure, and the door shut. The saw idled, revved up, idled revved up for several minutes. Everything is computer monitored. Temp, fuel consumption, emissions, ..
The carb adjustments are made with robotic arms according to whatever the computer says. If the saw passes it is cooled down and put in a box with the limiters fixed where the program says to fix them and shipped out. There is a long row of these test/setup enclosures.
No, we don't start them again unless asked to. There is nothing to adjust.
Obviously, if you are replacing a bad carb with one that the limiters either are not engaged or it never had them it is a different story.

I was curious myself because I have never sold a new saw. I just fix stuff. So, I asked one of our Techs who has done the three day deal at Va Beach.

Are all Stihl saws made in the US now?

 

[Marley5]

Are all Stihl saws made in the US now?

No they are made all over the place now Germany, China, Brazil, Japan and US

 

[ZeroJunk]

That’s fine for auto tune but not every destination is the same elevation and climate as Va Beach

Nothing to do with auto tune. Every saw. Every saw.