New to this forum so......hello everyone! I just bought a new ms391 and am interested in possibly doing a muffler mod or porting. Has anyone done this yet to a 391? I saw one guy had done a muffler mod, then upgraded to a new/bigger saw. I didn't see where he said if the mod did much to help or not. Thanks in advance.
The 391 is not a popular saw to do port work on because of the clamshell design of the engine. Port work is certainly possible but raising compression and making certain changes to port timing is very difficult because the clamshell design makes lowering the cylinder complicated. This would limit the gains possible from port work. A muffler mod however is pretty easy to do. Not owning a 391 however, I would not be able to tell you if it's a worthwhile effort. I would start by enjoying the saw as is, or if you are looking for a saw to modify, trade it for a "pro" model that will readily accept performance mods. And Dave, welcome to FHC!
Welcome RacerDave24 to FHC...Good Advise that MasterMech gave. What you are looking at the saw to do for you? Processing? Cutting around the property?
+1 on what Master Mech said above. I have done a few of those saws and a muffler mod will wake them up a bit. You will like it, your neighbors won't.
Thanks for all the replies. I have a total of about 35 acres to maintain. Plus my parents property of 30 acres. Anything from small saplings to large oak and hickory. 8-10 cords a year on average. I don't NEED the saw to perform better as what little I have cut so far with it, it has done well. I just WANT it to perform better. Being that I am a hot-rodder and racer, I don't own much that hasn't been "tweaked" just a bit. The old Shindaiwa I had gave up the ghost 2 weeks ago so I ended up getting the 391. Now I am wishing I would have spent a little extra and gotten a 362.
Did you buy it from a local Stihl dealer? I know my local dealer would take something back(you might lose a bit) especially if you are spending more money. They want you to be happy
Yes, I plan to call them tomorrow and see what they say. If I'm lucky, I might just end up with that 362 afterall!!!
RacerDave24, I completely understand the I want statement. Well hopefully that dealer will work with you. On the upgrade.
I hate to see us convert every person who has purchased a homeowner grade saw, for a Pro grade saw..... But, the 362 will out preform and likely outlast the 391. Also, modifying the 362C-M is a much easier task, and because it's an Autotune saw, it is always in perfect tune. With that said, the 391 is a great saw and will take well to a muff mod. So if you feel it will handle the firewood duties that you have at hand? Keep it and run the snot out of it!! Oh, and the member that traded the MS 391 for the 362C-M, ended up trading the 362C-M for a 441C-M. I think he finally found the right saw for him. Welcome to FHC!! You came to the wrong place for saw advice! ! We will tell you that you don't have enough, or need more saws!! Just kidding (not really). Lots of knowledgeable people here that are always willing to help out and give helpful advice!
Best upgrade for that saw is to trade it in... But might as well save some time and money and get a 261 or 441. Because eventually you will want both.
You can cut a lot of wood with that saw. Until a few years ago I just had a 390. It and a sharp chain did everything. But then I found pro saws and big saws. Love them now. Reading this I almost had to check to make sure this was not Griz posting And mike you made me chuckle at that post. Welcome to the saw hoarding club...I mean wood hoarding club!
trading up if you are not happy with an initial purchase should not be frowned upon, I did it with my tiller(cub cadet but also my stihl dealer) they were gracious in the process of swapping me for a model that did what I needed. I buy chains and bars from them, power heads are already broken in by others - because I'm frugal
I had a Stihl 390 for over 8 years. It was dependable but lacked in the torque department for me (bogged in larger wood and cut slow). I sold it and bought a 660. If you keep it a muffler mod would help. If you want something more powerful look at a 441cm or a used 440. I'm sure my buddy, Kg461, would suggest his ported 362cm. Mod the muffler, use quality oil, tune it properly...unless it's M-tronic, and keep a sharp chain and it should serve you well.
It must be something in the air, but I hear a 362 calling my name. Should be in the garage tomorrow afternoon. The Shindaiwa was a 488 that my dad purchased new years ago. He and I had both run it hard and rebuilt it several times. He bought a Husky and I took over the Shiny. I finally traded it to a neighbor who wanted to rebuild it for some car parts. That's how I ended up buying the 391. I knew when I was standing in the showroom I would regret not getting the one I originally wanted. I just can't keep anything stock. I probably have the only Exmark walk-behind with a thermal-ceramic coated muffler.
The 390 with a muffler modd is ok up to about 20". If I were to buy a pro saw bigger than the 390 I would get the 460/1. Only a tad heavier and not much more than the 441
