How to Modify Stihl 039 / MS390 Chainsaw Muffler & adjust Carburetor - Shredder II
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- Опубліковано 26 лип 2024
- Stihl chainsaw 029/290, 031/310, 039/390 dual-port muffler modification and how to remove the "limiter tabs" on the carburetor air/fuel mixture adjustment screws. Plus... instruction for super-tuning the Carb on most modified Stihl chainsaws. Increased speed and torque means less work, improved fuel/air flow means less heat... This is a must do for any mid-range saw that's used on a regular basis.... Now, that's how it should be.
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Out of all the muffler mod videos your's is the best one start to finish. It's nice that you show what to do with the carburetor with the "limiter tabs". Also you killed it with drilling out the air filter cover (it looks awesome). Thanks for your video it was a big help.... not like the other tool bag videos that the other people put up.
Thx, glad to have helped..
I'm proud of my tool bag videos.
bought an 029 yesterday went out and cut with it once and it was great. got home watched your video took apart the whole saw rebuilt everything, new plugs, air filter, fuel filter, etc. then i did this upgrade and it was a world of difference. cuts so well, and so fast now, it doesn't even seem like the same saw. i am 16 and love working on saws and this video really is a miracle worker. thanks brother!!!
Awesome... Gotta dig that piped-up feeling, makes a guy wanna get his saw on. I'm probably grinning as big and proud as you are!! Like you, I started young. First working on my Dad's falling saws (.044, .056 super AV's) at 12 and fell my first 36" fir at 14... yet wasn't "legal" to work with power saws until 18... don't think I didn't cut and sell alot of wood thru high school :) Keep up the good juju and stay safe...
Thank you for explaining in plain english how to properly tune a carby. I wrote what you said down word for word and went and followed those instructions on all 4 of my saws and they're finally where they should be.
..super cool to hear, thanks for sharing your success!! check out my channel or subscribe for the latest logging video uploads :)
I'd forgotten all about this video,and my saw,lol. I'd bought a ms310 about the time you put this video out and did your muffler mod and tuning on it. It had been a great firewood saw and ran alot cooler too. The coil went out on it a couple years ago and I just started using my other saws. I forgot all about my ms310 until now. I'm gonna pull it back out of mothballs and order parts for it. Thanks to you it not only got tuned,but itll also get a 2nd life.
Right on!!
Weeeeeee BLOODY PERFECT WAY TO DESCRIBE TUNING carburettor on a chainsaw 👍👍👍- 1 of the good videos of a man that actually knows what he's talking about , GOOD STUFF , KEEP SAFE N HAPPY CUTTING , AS THEY SAY IN IRELAND (HOW'S SHE CUTTIN )
Wow, thanks! exellent comment! :) ..and we be cuttin good today, don't ya know!
Excellent tutorial, this is precisely what I needed. I just picked up a dealer-rebuilt MS390, and it’s time to make some mods!
Enjoy and good cuttin'!!
Cool ..
Im doing my climbing saw thanks for the tips!
Great Video 1moonbuggy..... Thanks for showing everything with the mod: holes to drill in the exhaust, how to tune the carb, and drilling the air box. My MS 390 runs like a rapped ape. I love it and my neighbors love it too !!!!
Sweet, good to hear.. and tell your neighbors you can hook them up, for a price! ..stay sharp out there
Thanks for your video. I’ve got a low compression 039 that bogs down and I tuned it as per video and it’s much better.
I’ve got a cylinder rebuild kit on order and can’t wait to get it installed and ultra tuned.
Good stuff, solid plan..
Great video Moon buggy, I just did my MS 390 and there is a big difference, thanks
Glad to be of help... It sure puts a big smile on a guys face to hear and feel the increase of cutting efficiency. And to have done it yourself :) thanks for the support.
I'm currently modifying a MS391 with the new style muffler and will be posting the -before and after- with comparisons to stock as well as Shredder II...
can't wait to get out to the shop and duplicate this!! excellent vid
Excellent sound effects, sir. Great video, thank you!
Thank you kindly!
Awesome video! Very detailed and informative ! On a scale of 1- 10 you get a 9.5 ,nobody gets a ten.
Sweet... I've built a few of these now, two were 029s, and got 'Gold Stars' for each of those. With your 9.5 and six gold stars, I'm a shoe-in for milk wagon duty on friday :)
Thanks for the awesome feedback... just hoping to be helpful!
Thanks, great job, explanations are excellent!
Glad to be some help... see ya next time
Great video. Thanks a million...
nice, i did this to my ms210. sold it to a buddy now I'm going to do it to my ms290,husqvarna 55 and 455.
+Kimball Cody - Yeah, wakes 'em right up. Glad to be of some help and passin' down the good ju-ju... B-)
very cool and detailed video, thanks!
Glad to be able to put it out there... always awesome to see the benefits of a little self effort! Thanks for tuning in and adding to the good Ju-Ju... thumbs up!
Yes, excellent job! I subscribed. 💪
Thanks for the sub! and comment.. :)
Good video... Nice saw! Getting ready to do my new ms291 ... Kinda scared! LMAO! Pulled the 32" bar with full chisel skip chain right nice ....all stock! I think this will really help it rip!
+David Thorne - Thanks for tuning in. And yes sir you're on the right track... Tho the 291 may have the new style muffler and they've made it a bit more difficult to mod. I'll try to post the process... as I've got a 391 that's getting ready for the auction block ;-)
David Thorne 32 inch bar on a plastic saw with no power. wow lots of idiots out there david is one of them idiots. 290 and 291 are TURD home owner saws
@@Wanous-hv7zo A 32" bar is to long for an ms290,but the 290,310,and 391 are essentially the same saw. The do use a plastic housing,but the engine is metal and self contained. It bolts into the plastic casing. Aside from being a little heavy,they are great farm and ranch saws. An ms 391 is 4.5hp and nithin to sneeze at. A muffler modded ms291 will hang with a ms261 or 550xp,its just heavier.
nice work keep posting
+P.R. Pursell - Thanks, will do...
I have a MS460, my question the compression release when trying to start the saw i push it down and after one pull the release button releases and come up. Is that working properly, or should it stay engaged until the saw starts. Thanks for another great video modifing the mufflr and fine tuning the carburator , Thanks again George, st louis, mo
+George Edwards - Wow, sorry for the delay. It should stay down until the saw "pops', then push it down, half choke, pull again, starts, trigger, runs. It may be wore out or your saw has high compression causing pre-start release. I don't use 'em... I plug 'em, as they can and do leak. Run it, replace it or install a plug?... ....Drop starting a plugged 460 on a cold morning takes... full commitment :)
Does the oiler on 390 keep up with 28" bar? Great vids. Subcribed. Thanks.
+LoveStihlQuality - With-out a problem... mines turned all the way up and keeps up with the 32" bar as well
Good video have you upgraded the sprocket, and chain to the 3/8 it helps cut faster, and stays sharp longer.
Thanks!! and.. Yes, been using the floating rim sprocket for years on the 039 and have always run 3/8 .050 gauge (full skip chisel) on shorter bars and 3/8 .063 gauge on 32" and longer bars.. :) let the chips fly!
Hi moonbuggy
Love your work. My 039 is running a treat now. What size chain you running?
3/8 pitch .050 28in. Full chisel skip (Stihl RSLF).. all other saws run: 3/8 .063 32" RSLF
If you ever want to take rusted bolts of in less than one hour its atv oil mixed with paint remover varsol
Awesome video i know its old but im about to do am upgrade on my 290 that i picked up for free with a burnt piston to a 390 top emd from hipa. Why the holes in the intake cover? And where did you get the bigger chip deflector amd the bigger dogs? Please let me know thank you
..added a "winter" air filter and drilled the intake cover after the muffler mod for increased air flow to improve air in/out ratio.. clutch cover, chip deflector and dawgs off an 044
Wow! Great video Moonbuggy...How much would you charge to a do a MS 390 muffler Mod...I have one that runs pretty good...but I see the potential here for greater gains. Thanks Reggei
Is this English your speaking?
I speak in chainsaw, dog and squirrel.. rarely english :) :)
Great video! Thanks for the prep and not making us watch five minutes of drilling, the tape explanation was great.
Only problem I have is with your verbiage (slang) when doing the carb adjustment, etc....... totally lost me. If you could add a glossary of terms, that would be awesome...... maybe it’s simply because I’m the wrong kind of mechanic (bad one), but if I don’t know what you’re talking about, then I’m not gonna be able to replicate, which makes the video useless to me (and I’m assuming I’m not the only one, almost 70,000 views and only a couple hundred thumbs ups means I might be right on that point).
Thanks for the vid.
Hello enjoyed your video ion modifications. Like to know where your located. May I inquire the cost of you doing the work on porting out and exhaust modifications. Thanks NJ Blanchard
G'day mate, any particular reason for keeping the spark arrestor ? I havent found much use for them, and the heat off the saw is just as risky for fire risk it would seem, as any spark (which ive never seen come out).
Good video, cheers
Forester/Wildland Fire inspections.. all my saws go though it more than twice a year, at the start of fire season on every jobsite and then on each Fire/Faller assignment.. so I just make 'em cut with the screen intact.. Thx for the inquiry :)
@@redlinetimber yep. Fair enough. I'm using them for personal farm use. Gets very dry here in Australia, have to watch out if you're cutting in summer. Cheers mate
*I think it is a good modification, but the two-stroke engines can not or should not have the exhaust very open these engines need some retention of gases for proper operation*
yes.. about 20% restriction, the porting should be done to allow proper expansion of exhaust gases and then constrict/expell though a max. of 80%(or two 40%) of the exhaust port opening.. re-tune of the carb is madatory as well
I've just done the conversion and muffler mod etc. And I cannot get this saw to run right at any of these tunes on the carb. It w9nt even start at quarter out on the low and I'm lost on what the issue is. Good spark getting fuel etc just won't run right or idle without idle screw way in and adjustment s way off
Initial setting is, 1 and 1 turn out H/L from seated.. your issue is more than likely a case seal (that's not as bad as it sounds).. check for air leaks: impulse line, carb boot, fuel line... but probably dried out seals, **turn saw on its side while running and listen for it to smooth out or pick up idle**.. the side it changes on will be the leaky side, most often flywheel side. seals are realtive cheap.. pop the old ones, use a piece of alum can over the crank shoulder and some two stroke to slide new one down without losing inner spring, seat it and reassemble.. now run that sucker a few times a year to keep the seals from drying out. Let us know what you find, thx :)
Where or what mod did you do for the bigger chip deflector
..was a piece of a lawn mower deflector chute, cut to shape and size then riveted on thru back of clutch cover.. Si Bueno
With these modifications, what do you think the increase in power is over stock?
Maybe a shetland pony :) The big gains are in cutting speed and torque, the ability to maintain high rpms under a heavy work load or pull though a bind...
+1moonbuggy followed these steps and I am impressed with how my older 039 handles a 28" bar. thanks for the video.
what did you do to the air filter cover ?
Drilled it out and backed it with high flow filter foam. That coupled with a high flow air filter equates to a modified intake... it lets the monster breathe :)
So set my low to 1/4 turn out and high to 1-1/4 turn out and that's it. The carb is good to go?
you'll need to adjust them with engine running.. idle turned up to chain rolling.. then LOW up/down till its rpms reach their highest, leave it there..turn idle down to non- rolling chain.. (secure your saw) trigger to WOT, adjust HIGH in till it screams lean(sounds too good), then out till it burbles (billy goats), now back in 1/8 turn or so till it just starts to burb(needs that richness for cooling and stump snort).. that should have it in beast mode, tho may need a micro adjustment to the high side if its too lean in the cut
Hey I just did the muffler mod on my ms390 and after I have it at full throttle it takes several seconds to idle back down.
check for bound up linkage in your trigger handle or as it passes thru into the carb area..?
Make a vid on 250 mods please
could I do something similar to a line trimmer engine?
Yes, you could... measure the exhaust port and open the muffler to 80% of that, then re-tune the carb and let the grass fly :)
What is the fuel mixture for a modified saw like this?
50:1 Stihl mix and non-E 92 oct... but richer carb setting than stock
Where you get your chip deflector sir?
cut out chunk of conveyor belt, or this one was a piece of lawn mower deflector, pop riveted to back of clutch cover
Can I do this to ms 391 ?
yes, a little trickier modding the muffler, but ive done it with great results.. give it a go and let us know!! ..thx
What size bore does your saw have?
+ian “treejunkie101” martin - It's still stock at 49 mm w/same stroke as 440... for comparison an MS361 runs a 48 mm w/shorter stroke and an MS440 runs a 50 mm... and they can all be built as big bore with oversize piston and jug...
I have an ms290 and Im getting ready to put a 390 kit on it. Ive done the muffler mod and carb tuning but Im just not happy with the power yet. Plus I dont like bending over and a 28 inch bar is great for preventing that XD
ian martin 290-390 are heavy underpowered home owner saws. ms 440 weight is a little more with way more power and a pro saw
1970 olds442 really. cause my 171 cuts quicker than my 290 and its a $200 homeowner saw thats 32cc
1970 olds442 and my 290 cuts quicker than a 361 running a 18 when its got a 20
Will this mod work on an 044???
yes, only your going to be making the factory port at the top left of the muffler about 80% of the size of the exhaust port and leaving the spark arrestor intact..
I thought this video was a tool recipe to spring myself from prison 😜 actually a cordless angle grinder from Santa would be great 😁
Funny! ..along with a couple diamond cut off wheels and two charged batteries in a carrot cake with cream cheese frosting??
Thanks for the vid!! (in fear length will dissuade you, would LOVE to know your thoughts on this mystery-ridge I found at the back/beginning of my exhaust-outlet-port, it's like a sleeving or something it's weird but I look at it and it looks like I could/should be shaving it, it's compromising like 50% of my exhaust-port! imgur.com/gallery/Ji4smGH (this just got a muffler mod last night, and I used red/copper gasket-maker when reinstalling muffler as the OEM gasket was more restrictive than the exhaust-outlet's-tip or the muffler's entry-port, so just left it off instead of grinding-out a muffler-gasket..)
You mention it's unnecessary to hurt the baffle inside -- have you found that to be the case universally? I don't have any Stihl saws but almost all of mine have muffler mods and I'd have to check but quite sure at least 1 of them had no "front-to-back" passageway that wasn't directed through the baffling... I don't "aim for" the baffling but, in hindsight, do wish I'd been more careful to have left more of it in (I only removed significant baffling from one of my mufflers and yeah it definitely is louder than I'd like but I've definitely compromised the baffling on almost/all of them :/ )
How about clean-up? I've seen a lot made out of cleaning-up the muffler for shavings and I usually do my best however I did one last night & didn't have an air gun, after the 1st or 2nd bang on plywood I couldn't bang-out any more filings am guessing the remainder are stuck to the inside wall or the baffling, while you didn't show anything I'd love to know if you do go and spray-out mufflers before install (and what you'd do w/o an air-compressor....if I've *gotta* flush this thing I'm thinking if I'm lucky i'll get away w/ a couple cans of carb-spray, otherwise will soak-through gasoline so I can have it submerged and just shake/bang out any filings while-submerged!)
I was also very surprised by your initial carb settings, if you're putting L//H at 0.25 and 1.25 turns after the mod, what were they before? Or did you mean an *additional* 1/4 & 1.25 turns to L&H after the mod? The unit I modded last night is similar-enough to the lil echo 2511t, a 7lbs/25cc little thing, had this clone-saw for >6mo now and love it it's the only saw I've never had to touch its H&L in fact I don't even know which spline-drivers it'll take (glad I got the assorted pack!), to be crystal-clear here: Since saw was OEM and running great, broken-in but still 'running like new' and never had the H//L//Idle carb settings adjusted before, and you went in there and reallllly opened-up the muffler *and* you opened-up the airflow as well.....would Idle even need adjustment? Or L? I guess I'm picturing the increased-flow-potential as something that'll only alter performance once it's being revved IE that H adjustments are all I'll really need to do... BUT whether it needs H, or H/L/Idle, adjustments then while I appreciate hearing (and'll try!) your approach here, was hoping to ask: is there a way to tune L/Idle w/ the tachometer? I've found my tachometer's sole usage is letting me know I'm not revving too-high when not under-load (ie setting H jets so I don't hurt my saws), for L & Idle i've found I cannot get most units "center-range" for OEM-spec-idle-RPM if I set it by ear & by the way it feels good / has great throttle response / idles all day, so I always set everything by-ear except H, but would love to actually just pick up the tach, say "this unit's OEM idle is 3200 RPM" and set it to 3200RPM WITH the L jet feeling like it's optimal (I have to choose: keep idle RPM at OEM-spec, or have it sound/feel great on low-end/idle, they never match and this even happens w/ one of my un-modded units it's bone stock and same problem!)
Thanks again, will be tearing-through your channel now as I'm getting a backup unit or rather a "new work-unit" so the current one can be modded w/o worry, these come 25cc/1.2HP/7.5lbs am dying to get them screaming --- In considering some mild porting w/ my die-grinder I found something...odd, to me at least....there is a *massive* blockage at the top/beginning of my block's exhaust outlet port, it blocks view of much of the piston/cylinder behind it, I'm looking at this thing dumbfounded, unsure if it's some integral sleeving/compression/etc component that I'm not understanding, OR if it's simply a 'tab' they put in there to meet EPA specs...What do you think? It's that whole giant upside-down 'V' shaped 'sheet of metal' at the very start/deepest part of the exhaust outlet port: imgur.com/gallery/Ji4smGH What on earth?!?
we're addressing a couple of theses questions in a well to understand upcoming video.. "tuning chainsaw carburators the easy way".
As for the mystery-ridge: almost appears to be built up carbon/graphite; produced from heat, friction, fat-fuel and/or clogged exhaust??.. may have to pull the jug or rotate piston down and see if you can pop/break some out with minimal force, as in: it shouldn't be there? or is it solid cast or sleeve?
This dude looks American 🇺🇸 but was talking all sorts of Chinese explaining how to adjust the H&L 😂
Super funny.. :) thx ..and for the laugh!!
i drilled to byp;ass the baffle. also those mufflers weigh a fucking LOT. goddamn near 2 lbs it feels like. once i bypassed the baffle i'm like why do i even have this muffler on here? i need to put a lil pipe muffler or something to save some weight cuz that fker is heavy