Need Ideas on MS391

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Per the stihl website. 14.1 lbs 4.4 hp recomended guide bar lengths 16-20"
372 13.4lbs, 5.6hp recomended guide bar 16-28"
I'm no genuise but i'll take 1.2 hp anyday of the week with less weight.
 
372's are 5.3 or 5.4, depending on whether it's a xp or xpw. but i get and agree with your point.

Terry seems to be MIA??????

I was recalling from memory on the 372 specs. I'm definately not saw troll but yep you are correct
 
Per the stihl website. 14.1 lbs 4.4 hp recomended guide bar lengths 16-20"
372 13.4lbs, 5.6hp recomended guide bar 16-28"
I'm no genuise but i'll take 1.2 hp anyday of the week with less weight.

Is your book or info the latest, because this saw was sold from the factory with a 28" Stihl rollomatic at a price listed by Stihl at 560.00 Got the papper to prove it. I was also told the saw had been improved this year, but that could be sales man B.S. What I wanted to know was if anyone had any experience with this saw, and all I got was being told how stupid I was for buying it. And no the 391 does not scratch the 288 xp itch, but the 288 ain't dead either, not completely any way. I like to Hot Rod things this is new ground, I just was looking for someone with experience with these saws, like I said do the same port tricks lower the intake between .035, and .040 remove the cylinder base gasket and if needed raise the exhaust port, Other then that just kinda open things up watching to leave at least .100 from the piston skirt and mod the muffler. I was asking for tech not if you like the saw or not.
 
The 391 is to new. It is also not a "cool" saw to modify.

Are there things that could be improved, of course.

It is a factory saw, they almost always ship with big built in safety margins.

Tear it down and take a peak.

I have not seen any in use just holding dealer shelves down.
 
Is your book or info the latest, because this saw was sold from the factory with a 28" Stihl rollomatic at a price listed by Stihl at 560.00 Got the papper to prove it. I was also told the saw had been improved this year, but that could be sales man B.S. What I wanted to know was if anyone had any experience with this saw, and all I got was being told how stupid I was for buying it. And no the 391 does not scratch the 288 xp itch, but the 288 ain't dead either, not completely any way. I like to Hot Rod things this is new ground, I just was looking for someone with experience with these saws, like I said do the same port tricks lower the intake between .035, and .040 remove the cylinder base gasket and if needed raise the exhaust port, Other then that just kinda open things up watching to leave at least .100 from the piston skirt and mod the muffler. I was asking for tech not if you like the saw or not.

I don't beleive anyone called you stupid for buying it or anyhting close to it. Hell you spent close to $600 for a saw that many on here would like to have so congrats there. But I do believe that many merely pointed out that it's not a 372 which you insinuated it would cut with or outcut which just simply can't be. I have the smaller angine technology from stihl and it cuts way above the 35 cc's it advertise but I will never compare it to a 346. Now back to the original question which is all you wanted to know. Use the search button, I know theres quite a few good guys on here that have modded the new strato saws with amazing results. MOST of the saw builders are more than happy to point out what they did and what didn't work.
 
Is your book or info the latest, because this saw was sold from the factory with a 28" Stihl rollomatic at a price listed by Stihl at 560.00 Got the papper to prove it. I was also told the saw had been improved this year, but that could be sales man B.S. What I wanted to know was if anyone had any experience with this saw, and all I got was being told how stupid I was for buying it. And no the 391 does not scratch the 288 xp itch, but the 288 ain't dead either, not completely any way. I like to Hot Rod things this is new ground, I just was looking for someone with experience with these saws, like I said do the same port tricks lower the intake between .035, and .040 remove the cylinder base gasket and if needed raise the exhaust port, Other then that just kinda open things up watching to leave at least .100 from the piston skirt and mod the muffler. I was asking for tech not if you like the saw or not.

toward your questions:

if the new 391 is built like the old 390, you will not be able to remove the base gasket like you would on your older pro saws. the 390 was a clamshell design. as such the cylinder has half of the crank bearing holding area cast in to it. there is no gasket to remove and no way to effectively machine down the bottom of the cylinder either.
porting will be made moderately more difficult due to the cylinder being deeper from bottom to top. meaning, working the transfers and chamfering your newly ported intake and exhaust will be harder.
 
from stihlusa.com

RECOMMENDED RANGE
OF GUIDE BAR LENGTHS
40 to 50 cm (16" to 20")
STIHL ROLLOMATIC®

may stihl dealer can comment of whether or not stihl saws come with a bar in the box.
 
from stihlusa.com

RECOMMENDED RANGE
OF GUIDE BAR LENGTHS
40 to 50 cm (16" to 20")
STIHL ROLLOMATIC®

may stihl dealer can comment of whether or not stihl saws come with a bar in the box.

The bar does not come in the box, that is only on saws that are limited to twin packs.
Here we can get the 391 from the dist with bar range from 16-28.
We usually sell it with a 20" and occasionally a 25". For the larger bars we move the customer up in saw.
 
The bar does not come in the box, that is only on saws that are limited to twin packs.
Here we can get the 391 from the dist with bar range from 16-28.
We usually sell it with a 20" and occasionally a 25". For the larger bars we move the customer up in saw.

We only sell the 391 with a 16-20" bar.
 
I have a muffler modded ms390. It has a 20" bar on it. It runs that fine but I dont think I would ever put anything larger then a 25" on it. and then I would pu the 20" back on as soon as I could.
 
Look guys I let a couple comments get to me, I owe Brad especially a apology I am sorry man you have helped me when no one on here would, next time I will stop and think about what you have to say before I respond.
As for this bar thing there is what works on papper and what works for me, I honestly bought the saws this way like it or not it works, and works well, maybe it shouldn't I don't argue that, but it does work. I like it let it be, I believe that the 3/8 .050 skip tooth helps, I am also telling you this thing has some nut.
O.K. Clamshell design(now we are getting some where) so we are looking at something similar to the PM610 by Mac or Poulans new saws, where the only way to raise compression would be with a pop up piston. That means I need to find a good wielder and machinist. Perhaps mild porting would be the way to start. I retuned the carb and was amazed, apparently they tuned it to 11500, I brought it up to 12500, I think I can raise it more but would like to wait until I break it in more, but it wants more.
 
Look guys I let a couple comments get to me, I owe Brad especially a apology I am sorry man you have helped me when no one on here would, next time I will stop and think about what you have to say before I respond......

:clap:

Stop & think is always a good thing for all of us. Having a new member here commenting on his first new saw and definately real proud owner and all we do is tell him "welcome to the real world".

Oh well I still hope for you that some of these guys will still help you out. Excuses are usually also a good idea in person as a pm. ;)

Good luck & never forget ppe!

7
 
Look guys I let a couple comments get to me, I owe Brad especially a apology I am sorry man you have helped me when no one on here would, next time I will stop and think about what you have to say before I respond.
As for this bar thing there is what works on papper and what works for me, I honestly bought the saws this way like it or not it works, and works well, maybe it shouldn't I don't argue that, but it does work. I like it let it be, I believe that the 3/8 .050 skip tooth helps, I am also telling you this thing has some nut.
O.K. Clamshell design(now we are getting some where) so we are looking at something similar to the PM610 by Mac or Poulans new saws, where the only way to raise compression would be with a pop up piston. That means I need to find a good wielder and machinist. Perhaps mild porting would be the way to start. I retuned the carb and was amazed, apparently they tuned it to 11500, I brought it up to 12500, I think I can raise it more but would like to wait until I break it in more, but it wants more.
Don't worry about it. I've had guys on here tell me a husky 359 has no busines with a 24" bar and an 044 shouldn't pull a 32 yet I did it for many years. Theres no doubt that if the new engine design on the 391 is like the others it operates above the 64cc's it boasts. As far as porting and pushing the limits of the engine I personally don't beleive in it. I know the argument has been covered many many times but it's not a 67 mustang it's a saw. I personally think that a ported saw would be fun to have around but most are fine right from the factory and for the most part operate the way ENGINEERS felt they should. My rationalization was that you paid probably close to 6 bills for the saw and after mods are completed you wind up with close to the same cost as the 441 which is how it will end up running.
 
LMAO... Stihl saws don't come from the "factory" with bars on them...

...and I highly doubt a 391 would have a 28" bar on it anyways...

Gary

I do believe the dealer put a 28" bar on so that it would "sell faster."
As crazy as this sounds, my local Husky dealer says that many times he puts longer bars on because folks "like the looks of a big bar" on a saw.
 
I do believe the dealer put a 28" bar on so that it would "sell faster."
As crazy as this sounds, my local Husky dealer says that many times he puts longer bars on because folks "like the looks of a big bar" on a saw.

That's where I was goin' with that. The saw was on the shelf with that bar on it. Didn't come from the "factory" that way.

If this cats dealer told him that... his dealer is FOS...

Gary
 
I'm a nobody, but a couple months ago I bought my MS310, I wanted the MS390 for the extra 5 cc's but couldn't afford the $100 price difference. The dealers around here suggested I hurry and buy one of the older models because they are worried that the new model saws, the one series, will give people trouble and will cost alot more to repair. They said that the 310 maxed out at 20" bar and that the 390 maxed out at 25" bar. That's just here in NW Arkansas.

Help me out here... The new series have a small computer processor and computer chip that senses the air flow into the carb and adjusts the fuel mixture to accordingly.

I was also worried that you would not be able to adjust the carb due to the new features... So all of you are saying that you can?????

I am no mechanic, and don't trust any of the stihl mechanics around here now. My 025 was turned up to 12,500 and I love it. The problem is, that was 18 years ago and that mechanic doesn't do it anymore. I plan on turning up my 310 because it doesn't perform like I expected. Any suggestions on what the max rpm should be adjusted to??

Terry congrats on the new saw! I would have loved to have purchased the MS 390, or 391 I was just a little skiddish and couldn't afford it at the time anyway. Thanks, Chris
 
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