Stihl MS290 muffler modification.

[hotsawman1]

I have a Stihl MS290 chain saw with a 20" bar on it that i use to log with and to do tree work with. What i want to do is modify this saw for more power output starting with the muffler and go from there. I've been modifying all kinds of engines from car engines to go-kart engines to every other engine in between which includes building racing engines for go-karts and etc. but, and this may sound odd and im sorry if it does, im not too familiar when it comes to stock saws. My question is this, can somebody tell me how to modify the muffler on this MS290 which is only 1 year old and i don't want to screw it up so thats why im asking. I know just like any other engine the better the engine breathes and gets rid of the exhaust the better. I really appreciate any help anybody can give me. Im slowly learning how to modify stock saws so this would be a big help because i really want this saw to kick a_s when i go to work with it. Thanks guys.

 

[Bushmans]

If you use the search feature and type in "029 muffler" you should get about a billion threads to choose from with pics and everything. It's pretty common to MM an 029/290.
Good luck!

 

[jughead500]

i just done a ms390 muffler for a friend a while back.i also done my ms270.im sure your 290 is pretty much the same.you'll have to heat the crimp around the muffler with a torch and un bend it.cut the cage out and open up the outlet.make sure you get all of the shavings out.heat and rebend the seam.

 

[z71mike]

Just get your drill and pop a couple holes. It's a 290. There's not a whole helluva lotta 'hidden' power.

 

[lambs]

Do the search as was recommended. Search on Google like "arboristsite 290 muffler mod" or variations on that theme. I've not done one yet, but have done a lot of the reading. You can definitely screw it up if you drill it out too much. I recommend the sphagetti method to figure how the max for your saw. Search on that word too in your reading and you'll probably find it.

Once you open it up you will need to retune your carb to avoid under lubricating the motor. Don't forget that critical step, but with your experience you probably already know how to do that part. Brad Snelling has a great video on how to tune a saw out there demonstrating a saw 4 stroking out of the cut. Highly recommend you look at that one no matter what else you do.

Good luck with it.

 

[H 2 H]

MS 290 - 310 and 390 are all the same just do a search there is plenty info here on them :msp_smile:

 

[hotsawman1]

I have a Stihl MS290 chain saw with a 20" bar on it that i use to log with and to do tree work with. What i want to do is modify this saw for more power output starting with the muffler and go from there. I've been modifying all kinds of engines from car engines to go-kart engines to every other engine in between which includes building racing engines for go-karts and etc. but, and this may sound odd and im sorry if it does, im not too familiar when it comes to stock saws. My question is this, can somebody tell me how to modify the muffler on this MS290 which is only 1 year old and i don't want to screw it up so thats why im asking. I know just like any other engine the better the engine breathes and gets rid of the exhaust the better. I really appreciate any help anybody can give me. Im slowly learning how to modify stock saws so this would be a big help because i really want this saw to kick a_s when i go to work with it. Thanks guys.

Thanks to all you guys for the advice and info. It is a big help.

 

[J_Arena]

Stihl MS290 Muffler Mod Threads

 

[hotsawman1]

Stihl MS290 Muffler Mod Threads

Thanks a bunch J Arena. I will check them out for sure.

 

[MetricMuscle]

Good morning Arborists! I'm new and this is my first post. I am not intentionally reviving a thread who's topic is the most popular thing to talk about but I have some questions.

I have an MS290 and it has a muffler like the one pictured above. Seems like most folks just cut more holes in the muffler for increased flow and better performance. It makes plenty of power for what I use it for so I'd like for my saw to run reliably as well as it can but also be as quiet as possible without effecting performance.

I'm wondering if the OE muffler acts like an expansion chamber at all or is it strictly a muffler?

Does the empty air space surrounding the rectangular perforated core just help with muffling or is there another purpose?

Has anyone tried stuffing this muffler with Stainless Steel Wool?

I have seen expansion chambers on Trials Motorcycles which had a perforated core running thru them and stuffed with damping material so that it would act as both a chamber and a muffler. The engines on these bikes are not tuned for high rpm HP so I'm wondering if the need for the maximum tuning pulse from a chamber is moot.

 

[a. palmer jr.]

I've done a few 290s and 390s this last year, it's a good idea not to drill too many holes or too big because the saw will become too loud and won't perform that much better. Remember it has to have some mid range power also, it won't all be high rpm use. Those big mufflers are also expansion chambers of a sort because the exhaust collects in the muffler and gets sucked back also, like a motocross bike only on a smaller scale.