ms 391. i have a feeling this was a bad purchase.

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mrtoler22

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i generally only have a couple of smaller saws that dont get used too awful much just the occasional storm cleanup and a few loads of firewood a year. anyways a couple weeks ago we had a few windy days and i lost a largish tree roughly 23 in dia. none of the other saws i have were big enough and id been wanting to get a bigger one for a while i just hadnt done my research.............. needless to say i went to the local powershop and the biggest he had is the ms 391 so i picked it up and have proboably ran 2 gal of fuel total through it and dont have any complaints other that i was expecting more power. is there anything i can do such as muffler upgrades? ive only ran the moto mix in it, could it need richened up a tad? its still at factory specs on the carbs. or is this thing just a pile and i should go trade it in and get a 440 or 460? btw the guy told me it was out of the pro line up...typical salesman.
 
Do a lot of reading but yes you can. Mainly a muffler mod would waken it up a lot and adjust the carb setting. May have to pull the limiter tabs off but that and the muffler mod are pretty easy mods.
 
limiter tabs? as you can tell im pretty oblivious to all this. but im all for making things run better. and whats anyones thoughts on the motomix by stihl? and when running it should things be richened up at all?
 
limiter tabs? as you can tell im pretty oblivious to all this. but im all for making things run better. and whats anyones thoughts on the motomix by stihl? and when running it should things be richened up at all?

the limiter caps are little plastic red caps on your L and H carb screws, if you pull out the black rubber grommet that covers your screws you will see them in there, some people take them off with a dentists pick I wound up taking mine off with a small screw, just be careful that you don't run into the adjustment screw tops with the tip
 
I have the 391 and I like it for what I use it for. It should be just a little bit better on power once it is broken in some more.
 
the limiter caps are little plastic red caps on your L and H carb screws, if you pull out the black rubber grommet that covers your screws you will see them in there, some people take them off with a dentists pick I wound up taking mine off with a small screw, just be careful that you don't run into the adjustment screw tops with the tip

I run older Stihl saws, does anyone have any photo's of limiter caps?
 
According to Stihls info on that saw, they recommend a 20" bar as max. Wonder why the dealer sold it with a 25" bar? Put a 20 on it and it will run better. I think I would go that route if the saw is new. Any mods would void a warranty if it was needed I would assume. I plan on getting a 391 soon myself.

Rob
 
Motomix looks like some good stuff other than the price. Its straight gas(no ethanol) and Stihl Ultra premixed at 50-1. Place I work at just bought two new FS90 weedeaters and he put moto in one and ethanol in the other. He didnt adjust anything different on them carb wise. :msp_wink:
 
According to Stihls info on that saw, they recommend a 20" bar as max. Wonder why the dealer sold it with a 25" bar? Put a 20 on it and it will run better. I think I would go that route if the saw is new. Any mods would void a warranty if it was needed I would assume. I plan on getting a 391 soon myself.

Rob

I am a complete newbie so take this with a pinch of salt. But I was wondering the same thing as rob said if the bar is too big for the saw.
CR500 has a 25 and a 20 on his, he should be able to answer this better.
 
Yeah, I think my first "mod" would be a 20" bar and chain. 25" is a lot for that saw. After a few gallons of fuel, it should be running good.
 
391 bar ?

Your 25" bar is running which chain safety or non safety? The 391 with a 25" and semi skip non safety chain is the bomb,especially if the riders are dropped a few thous:rock:
 
First thing is first the 391 replaced the 390 which was rated up to a 28 inch bar according to Stihl. Thus making me think that a 25 inch is a possibility for my saw and 390s. The 391 can turn the bar pretty good for the most part(would not leave it on there full time though) it is not as fast as lets say my 044 with the same bar or even the 32'' bar. If you can keep the the chain speed up with the 391 it can cut pretty good not the best but not bad.
Most people say why would a person get a 391 when they have a 044? The reason being is that I got a pretty good deal on the saw and I needed a good firewood cutting saw. Also having an extra saw is a nice thing to have going into the woods in case 1 saw gets pinched or 1 saw breaks. 1 thing that I like when I use it it to cut fire wood is the better anti vibration system, The 044 is not bad but the 391 is just a pinch better for those long days.
Here is a pic of the 25 on the 391.
 
yep thats the same bar i have. i do not know why on stihls website it says to only run a 20 in bar. all the 391's i have seen have had the 25 in bar.
 
Bar

Mostly short bars and safety chains are on saws as a liability issue. The 390(1) saws are fairly good saws for power. I have run my BIL 390 with a 24" bar and full skip and the saw is unstoppable in hard wood.
 
arrowhead can you pm me with some ideas. im 2 1/2 hours away but thats not an issue. and yes im a dumb@$$ when it comes to knowing things about saws but how do i tell the difference between a safety and non safety chain? im just running whatever it came with.
 
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