New to forum...just bought MS390...

And its a beauty...it seems to bog down a little in cuts, I'm wondering if I'm asking too much of it...it's pushing a 28" Stihl Rollomatic ES bar with 3/8"X.050 chain. I'd like to keep the long bar as it is much more than I really need for firewood cutting but nice when I might need it for larger wood. On the other hand I don't want to hurt anything. Is there any reason I can't change the bar nose sprokect and drive sprocket and run .325 pitch chain...and if so how would I figure how many drive links I would need? I appreciate any help. I' not a professional and my previous experience is withe the 025, 009 and various less nice consumer saws all of which have less options, so I'd like to hear what y'all have to say.
Thanks, J.D.

So in your opinion the 28" bar is too much? Why would .325 be a bad idea?

Yeah, that 28" is a bit long for that saw. I'd run a 24" at most on it, but the 20" that TreeCo mentioned would do very well. I'd also stay with the 3/8" chain, but shorten that bar down a bit. Keep the 28" for when you need it, but run the 20" all other times. And if you keep it all in 3/8", you won't have to change your sproket on that saw, which when you go to replace it from use, I'd swap it out in favor of the rim type sprocket instead of the one piece drum sprocket that it should've come with.

Jeff

Yeah I knew the 28" was a bit big. I figured I knew a tree surgeon who runs 25" hardnose bars on the 038s and they perform pretty good, thought the 28" sprocketnose would be OK, but I can see the performance isn't what I'm used to. Is the MS390 going to have a lower cutting speed than my 025 anyway since its a bigger heavier saw or is it just that way because I'm lugging it?

I'd say it's because of the bar length. A 390 will have no probelm pulling a 20" or even 24" bar with plenty of speed and ease. Most would say to go with an 18" or 20".

And I'm not sure of the 038's hp numbers, but I believe they're higher than the 390's, especially the 038 Mags. They really aren't comparable saws.

Run that 390 with a 20" bar, and it should perform and cut fine for you as long as you keep it within it's intended niche, which is homeowner/farm work. Don't ask it to cut like a 44 or even a 38, and you'll be plenty happy with it. They're decent saws. I had a 310, and was pleased with it within it's intended useage, and it's a saw below the 390.

Jeff

If you realy want to keep the 28" bar you may want to check with your chain supplier to see if they have skip tooth chain.

Thanks for all the suggestions guys. I'll have to see what I can come up with. Yeah this guys saws are 038 Magnums. Thought they would be comparable. Don't really know much about Stihl's older stuff.

If I recall right, the 038 super, and Mag was a 72CC saw, with around 5HP or so, maybe a tad more. NO comparision between an MS 390, and 038. the 390, is a large homeowner grade unit, the 038, is a pro saw comparable to the 044/440.

For an ms390, I'd run the 20" bar, 24" max, as others have said, and sitck with those, but it can pull a 28, IF you arent planning on setting a world record, or cutting a ton of large stuff like that. but as I said, dont plan on setting a speed record with the 28" bar, or the 20" on that saw for that matter. if ya wanna cut fast, get an 880 and let the chips fly.

Diesel JD said:

So in your opinion the 28" bar is too much? Why would .325 be a bad idea?

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In Stihl chain the .325 and 3/8 have the same width cutters or very close, so the kerf would be pretty well the same.

28'' is wee bit long for that, depending on what you are doing Carlton make a 23 inch Premium sprocket tip that would fit nicely on your saw.

www.sawchain.com

Alright most of the stuff I'm cutting doesn't use half the bar's capacity, and speed is not that big a concern. What I do worry about is damaging the bottom end of the engine from lugging. Some of you guys have told me that .325 chain is not as good as 3/8" but I've used it and been real happy with it before, something like Stihl 23RS or Oregon 33-34-35LG. Does Stihl even make .325" tips for the ES or would I be forced to buy an Oregon Bar set up this way? I know the .325" isn't quite as good, but for what I do it's good enough...what I guess I'm tring to find out is if running .325" will take enough load off the saw to make the 28" bar feasible and if so is there any safety or mechanical problems that would arise from using .325 in this application. I kind of have myself in a pickle having bought the 28" bar and not wanting to put it on the shelf or beg the dealer to take it back and set me up with a smaller bar, which would mean money out of his pocket.

For a 3.9 cubic inch saw 28" is a bit too much. It can handle it if you don't push it. But like EVERYONE else said 24" you will have no problem with.! Have a great day, and God Bless!

If you are set on keeping the 28" bar, you should use skip link chain, and stay with the 3/8. Better yet, keep the 28" (skip link chain) for the big stuff, and get a 20" bar for your everyday cutting. Also, after getting a 20" bar, give your saw a chance to break in. The power will pick up.

I think you may be barking up the wrong tree with the .325. It isn't going to save you enough if any hp to make that 28" run noticably faster. Stick with 3/8" and a 20". You can find new factory Stihl bars on ebay for decent prices. Keep the 28" for the few times if ever that you'll need it, and run the 20" at all other times. Chalk it up to experience gained. By the time you convert the saw's sprocket to .325, get a new 28" chain, and manage to find a 28" bar in .325 (or hardnose) you're gonna be about the same dollar and hassle wise as if you'd just bought a 20" Stihl Rollomatic E and kept everything 3/8". Plus you're not gonna be any noticably better off.

In fact, here ya go-
http://cgi.ebay.com/20-Stihl-Chainsaw-Bar_W0QQitemZ7712937416QQcategoryZ85915QQrdZ1QQcmdZViewItem

And there's several other Oregon, and GB 20" bars on there too.

JMO. It's your saw.

Jeff

A 390 wont pull a 24" bar worth a ****, let alone a 28". Before anyone spouts off I actually own a 039.

Ben you need modded saws for the work you do, Deisel doesn't say he's into this day in and day out. Otherwise he's going to end up with sawitius (one modded saw is not enough) like Rawtreelimbs and the rest of us, ease him into sawitius. Deisel needs a 20" bar and the same size chain he is using, the 3/8" for his MS390 because he will not see enough difference changing to .325 to be worthwhile. The change to a 20" bar will make a difference as would changing to full skip chain on the 28" bar and using a light touch with a sharpened chain. If Deisel goes for the 20" bar and 3/8 chain and the full skip on the 28" bar 3/8 chain in no time he'll be having fun with better preformance and then he'll come down with a severe case of "got to have another saw or two" (sawitius). Then he can step into pro series saws and then to modded pro saws. Afterwards it will be time to join the 12 step program. So, let's get him set up with better MS390 preformance with 20" bar 3/8 chain and on his way to a severe case of Sawitius which can only be satified with a large collection of modded pro saws and antique big bore saws.

Deisel, first things first, 20" bar and stay with the 3/8 chain, you don't want to switch to the smaller .325 chain on an MS390. Get the chain sharpened for the 28" bar and save it for the really big stuff. When you use the 20" bar and chain set up you'll notice the difference in performance. Then when you wear out the chain you already have on the 28" bar cutting big stuff change to full skip for the 28". OR get the 20" bar and have the shop split the 28" chain and make it up for the 20" bar now and buy the full skip chain for the 28" bar. Stay with the 3/8 on your MS390, just use the shorter bar for most of your work and save the big bar for the bigger wood (over 36").

Yes, I should have said "full skip" instead of "skip link." Thank you Geofore.

How about I go with a 24" sprocketnose or 21" hardnose and then save the big bar with full skip for big wood? Is there any reason I shouldn't split up the Stihl 33RS 91 for the correct bar and get something like the Bailey's 30RCS skip for my 28? Thanks!

Diesel JD said:

How about I go with a 24" sprocketnose or 21" hardnose and then save the big bar with full skip for big wood?

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Now you're hearing us!

How about a 20" Stihl like the one in the ebay auction I posted the link to? I wouldn't go hardnose unless you're gonna be stump cutting or working in dirty stuff.

Jeff

And oh yeah, that 33RS would work fine that saw.

Jeff

George, I already have a modded saw or two with more in the works. I am talking real modded saws here , not warmed over muffler mods and air chisel porting.
The fact remains the 390 sucks with a 28" or 24" bar. Will it cut with one? Yes, but so would a 260. I would stick with a 18-20 for a 390.