Stihl 391 Chainsaw

[3chester]

If the spark is weak, clean the flywheel magnets, if ya got high humidity or wet conditions, they lose that coils power. If the magnets are really corroded, use a little Dremel tool wire brush, on em to clean. If the magnets are tarnished bad, a guy should look at the coils pickups too, remove bolts, and shine them up while ur in there. Gap em with a $5 bill laid flat, between the coil and flywheel magnets.

 

[HockeyDad]

 

[akdad]

Len,
I've used avgas a fair bit. Actually a lot In snowmobiles and just about everything it's very stable but it will make it harder to start. If it's cold it really shows. But I'm talking quite cold. You make want to change gas.

 

[Coyote Shadow Tracker]

Len,
I've used avgas a fair bit. Actually a lot In snowmobiles and just about everything it's very stable but it will make it harder to start. If it's cold it really shows. But I'm talking quite cold. You make want to change gas.

Thanks.
We are in 80-90 degree weather. There is a cover plate in the carb for winter and summer for air temp. I don't think that it has anything to do with gas. I use a 50/50 Av gas and no ethanol 100/89 to get about 94 octane. I think that it is mostly my lack of ability to pull hard enough and so many times. When starting the Stihl have to get that "Burp" and then change the choke setting. You really have to master the "Stihl Technique" in starting them.
I am not skilled yet especially trying to start the MS 391 4.4 HP.
I had two other people just pick up this new saw and they started it up in several pulls.
I guess that my lack of strength and spinal cord injury limits me from being former Mr. Iron Man to Mr. Dudly.
Was just looking for easier ways to start the 391.
I learned some good info from everyone
Wish they made them with an electric starter.

Maybe it is a sign that I should not cut this big tree by myself
I still think that I am in my 50s and a young man.

Thanks much!!!!
Len

 

[MtPockets]

Wish they made them with an electric starter.

I'm thinking kick starter.

If you drop kick it like a football and a neighbor sees it, maybe he'll come give you a hand?

 

[Coyote Shadow Tracker]

I'm thinking kick starter.

If you drop kick it like a football and a neighbor sees it, maybe he'll come give you a hand?

You are FUNNY!!!
I already went to the foot Dr today for both big toes on each foot where I had blood blisters from hittin my big #14 feet into things. I am sure if I kicked the chainsaw I would probably lose a toe or two.

 

[Doghunter23]

How To Perform An M-Tronic Reset | STIHL Blog

STIHL M-Tronic machines are designed to perform at their best at all times, but they sometimes need a reset. Find out when and how to reset them here.

blog.stihl.co.uk

Gotta do an M-tronic reset! Stihl saws are electric controlled I have a MS 441 and after running a few tanks through it I could not get it to start for any thing, even when it would fire it would immediately die. I was very upset after spending all that money on a big saw then it wouldn't run.
Then I found how to reset computer it starts one pull and purrs like a kitten.
The computer learns how the saw runs and adjusts carb and fuel. The big trick is once done running for the day you just dump out remaining fuel and let it just idle until it dies. That way it learns how to maintain an idle. ZERO problems after this.
For starting I pull rope on full choke slowly three times to prime, push in pressure valve and give her one big pull. Starts first try

 

[Troutslayer2]

I have a 390 with a 24" bar and it runs like a champ. My sawyer buddies get that thing ripping in one pull. I seldom use it and I do not have the Stihl touch, I struggle to get her going when cold starting.

 

[Coyote Shadow Tracker]

How To Perform An M-Tronic Reset | STIHL Blog

STIHL M-Tronic machines are designed to perform at their best at all times, but they sometimes need a reset. Find out when and how to reset them here.

blog.stihl.co.uk

Gotta do an M-tronic reset! Stihl saws are electric controlled I have a MS 441 and after running a few tanks through it I could not get it to start for any thing, even when it would fire it would immediately die. I was very upset after spending all that money on a big saw then it wouldn't run.
Then I found how to reset computer it starts one pull and purrs like a kitten.
The computer learns how the saw runs and adjusts carb and fuel. The big trick is once done running for the day you just dump out remaining fuel and let it just idle until it dies. That way it learns how to maintain an idle. ZERO problems after this.
For starting I pull rope on full choke slowly three times to prime, push in pressure valve and give her one big pull. Starts first try

WOW I need to try this. Our 391 with a 24" bar is a brusier and will CUT. I almost always have a hard time starting. Other experienced operators start it right off the bat. We have a GAINT Pine tree (I can only put my arms half way around when hugging it)that was hit by lighting and is now dead. It has (3) trees growing out of the main trunk about 15' up). If it falls toward our house it will take off our covered deck and the corner of the house. I need to cut it down and trying to get the courage up due to my spinal issues. I have cut a lot of trees in my younger years so I know how to cut and which way it will fall. Just want to make sure that I can keep the 391 running once I start.
we also have a MS 180 for Bucking and small trees.
Had a tree removal company stop by the house by chance (wrong address) and I asked how much to cut down. Was told $3K to drop it + removal costs if wanted it gone. Heck for that cost I can put some ropes and pulleys along with my truck and tractor and take it down.
When I do it, I should have our Go Pro videoing it in case it goes the wrong way

 

[Doghunter23]

The way to tell if its electronic or not is in the third number if it ends in a zero- no electronic a 1 or 2 first or second generation electronic. 390 none 391 first generation and so on. I have had to remove several large oaks near the house two of which were leaning bad to the house. I used my buddy's technique as he is a professional power line clearance guy. I climbed extension ladder as far as I could and set a choker as high as I could and connected to 4X4 winch, 12,000 lb. Cut an open face cut, bout 1/3 of the way through, take slack out of the winch. Start my back cut and leave a huge hinge like 4 or 5 inches than winch in and shim the heck out of it till leaning where I want it than either thin out the hinge wood more- or winch it on over if it might go.
From experience just make sure your cutting into good wood, terminate damage or hollow trunk will require a rethink and more strategy!

 

[Oak_Leaf]

WOW I need to try this. Our 391 with a 24" bar is a brusier and will CUT. I almost always have a hard time starting. Other experienced operators start it right off the bat. We have a GAINT Pine tree (I can only put my arms half way around when hugging it)that was hit by lighting and is now dead. It has (3) trees growing out of the main trunk about 15' up). If it falls toward our house it will take off our covered deck and the corner of the house. I need to cut it down and trying to get the courage up due to my spinal issues. I have cut a lot of trees in my younger years so I know how to cut and which way it will fall. Just want to make sure that I can keep the 391 running once I start.
we also have a MS 180 for Bucking and small trees.
Had a tree removal company stop by the house by chance (wrong address) and I asked how much to cut down. Was told $3K to drop it + removal costs if wanted it gone. Heck for that cost I can put some ropes and pulleys along with my truck and tractor and take it down.
When I do it, I should have our Go Pro videoing it in case it goes the wrong way

I don't think the 391 has M-tronic. Look to see if you have adjustment screws for the Hi and Lo jets. If you do, then you do not have the M-tronic.

If you're having starting issues, like someone said try non-ethanol fuel greater than 89 octane first.

Second, check your exhaust screen for carbon buildup. Every once in a while a new saw can clog that screen up if it was running too rich from the dealer.

Last, for cooler weather (denser air), you're gonna want richen up the Lo jet a tad by turning it CCW, maybe a 1/16-1/8th turn. When you get it running adjust that jet slightly until you get a smooth idle. You may have to tweak it throughout the year as temps change. Rich in cooler weather, leaner in warmer weather. Otherwise, the 391 is just a big saw and may take a few pulls to prime if it's been sitting.

 

[Doghunter23]

I don't think the 391 has M-tronic. Look to see if you have adjustment screws for the Hi and Lo jets. If you do, then you do not have the M-tronic.

If you're having starting issues, like someone said try non-ethanol fuel greater than 89 octane first.

Second, check your exhaust screen for carbon buildup. Every once in a while a new saw can clog that screen up if it was running too rich from the dealer.

Last, for cooler weather (denser air), you're gonna want richen up the Lo jet a tad by turning it CCW, maybe a 1/16-1/8th turn. When you get it running adjust that jet slightly until you get a smooth idle. You may have to tweak it throughout the year as temps change. Rich in cooler weather, leaner in warmer weather. Otherwise, the 391 is just a big saw and may take a few pulls to prime if it's been sitting.

your right! I have an ms180 ms270 and ms441, the only one with m-tronic is the 441. I got the number thing all wrong. I just saw the second gen electronic coming out on some models designated with a 2 for last digit. If you can adjust the carb it's not M-tronic. I have a 36 inch bar for the 441 that it will run just fine for really big timber, but she just absolutely screams with the 25 inch light bar.
That being said maybe he needs to downsize saws, I have dropped some really big wood with the 270 with 18 inch bar. Just need to cut face cut from one side and match up cuts with other side, I don't like that often because you're kinda blind on the back cut. Run more risk of cutting too much hinge wood.

I can sympathize with the spine injury.. got bad nerve damage in my right shoulder and just a dumpster fire for a back! If I were a smarter Man I would probably quit doing it, but I like the way wood heats the house, and I have to keep the lane clear.