# Stihl MS 170 Mod Oh Yeah Baby!



## tmessenger (Feb 17, 2014)

Holy baby bumble bee batman.........

This little guy came along as a free ride with another saw I bought so why not. This is a bit of a mix with a 170 cylinder / crank, an early 017 single ring piston and 017 chassis, so sort of a 017 in drag. This one got the muffler-ectomy, a cheap china fully adjustable carb and a micro .043g 14" B&C.

The saw went from being a dog before the mod into.............well another dog but a different kind of dog like from being a chiwawa into being a miniature wiener dog if you get my meaning, so in other words quite a difference.

The good: Ultra light at around 10 pounds wet with B&C. Big old oil and gas caps (others should catch on to this) so you can actually see in the tanks when filling and not over filling. The tanks are translucent so you can check fuel and oil levels on the fly. Lots of cutting on a tank of gas for you penny pincher. Easy to come by for not many $$ and loads of used parts around. With a mod and sharp micro chain it's a usable very light saw for thinning and limbing.

The not so good: Choke is either on or off, this saw would like half choke for 5 seconds on cold starts so when it's chilly out it usually has to be started a couple of times to get some heat into it to keep it running. The plastic case has lots of nooks and crannies that trap oily sawdust behind the engine and the only way to really get it clean is pull the engine. You have to pull the handle bar off to get the starter housing off (bad design IMO). The micro .043 Rollomatic is a junk bar and has no business wearing the Rollomatic name, they should call it the Rubomatic or Ruinomatic. I got a couple of them used cheap so I'm good but if buying new I'd look at an Oregon brand it might be better made. These clam engines are not very high compression (around 140psi if healthy) and there is nothing that can be done about it.

Things to consider: The early 017 and the 170 are different engines with different almost everything so mixing parts for the most part does not work. The 170 has quad transfers and a double counter-weighted crank vs duel transfers and single counter-weighted crank for the 017. The early 017 engine does not mod very well or run as smoothly and really is not worth the effort, I'd stick with the 170 engines. These saws need all the help they can get so the micro bar & chain are a must IMO. The china carb is a bolt on without tweaking, the stock throttle linkage works without any tweaking and the carb is under $10 shipped so not a bad deal. I did have to grind a little of the 017 plastic air filter housing off to clear the longer mixture needles on this carb and add another hold in the engine cover for the high speed jet adjustment.

And to save Mr. SawTroll the trouble: yes we know this is not a professional saw, never was intended to be and never will be and no I'm not going to throw it in the dumpster, well as least not yet. 

Video disclaimer: This video was made by a trained professional, DO NOT TRY THIS AT HOME.


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## z71mike (Feb 17, 2014)

Kewl. Thx for the writeup, man. I been trying to buy my buddy's 170 for a year now. He bought it to drop the only tree on his property. It's down now and he doesn't burn wood. Can't see a reason for me not to take ownership


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## tallfarmboy (Feb 17, 2014)

That already sounds better than every 170/017 that I've ever heard... I get so frustrated with non-adjustable carbs. Glad to hear the ChiCom's are at least working decent... and at less than the cost of a carb kit, why not give one a try?


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## bezza1 (Feb 18, 2014)

ya dont need to pull the handle off to get the starter cover off only the fuel and oil caps
ive built 2 ms180 s today out of my parts pile im giveing to my farther in law he has a old stihl 07 and its getting heavy for a general house cleanup


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## treesmith (Feb 18, 2014)

Love my 170, modded the muff, fitted the walbro adjustable carb and advanced the timing, wears 12" .050 Stihl and it runs great. It gets battered as a chipper saw for an arb company and its not died yet

Sent from my GT-I9100 using Tapatalk


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## fuzz1500 (Feb 18, 2014)

Love the 170/180 as well . Great little saws for what they are . Ive been keeping my eyes open for a good one as well ! Nice work on that one


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## o8f150 (Feb 19, 2014)

heres the one I did and still have,, wt 215 carb and mm


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## Rockjock (Feb 19, 2014)

Here is my 017 adjustable carb and no MM


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## z71mike (Feb 19, 2014)

No MM? God why?!? Haha


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## KenJax Tree (Feb 19, 2014)

Scott i bet your splitter recoil loved you after that.


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## o8f150 (Feb 19, 2014)

KenJax Tree said:


> Scott i bet your splitter recoil loved you after that.
> 
> 
> Sent from my iPhone using Tapatalk


it did ,,, 2 minutes of running and it was all cleared out though


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## stihlfanboy (Feb 19, 2014)

New to the forum. Have an ms170 stock other then a .50 3/8 16" bar. Still have the micro bar to. What can I do to give it alittle more power? Just my back up saw to my o28 and ms311


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## Rockjock (Feb 19, 2014)

z71mike said:


> No MM? God why?!? Haha



Well if I MM it I am afraid it will out run my 440! I just never thought about it. It runs great as it is. If it aint broke don't fix it I guess.


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## z71mike (Feb 19, 2014)

Or...... if it runs good, make it run better! Bore it out!


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## brian22 (Feb 19, 2014)

Can anyone tell me the part # for a adjustable carb for these saws?


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## z71mike (Feb 19, 2014)

WT215 according to Scottso


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## Chris-PA (Feb 19, 2014)

Rockjock said:


> If it aint broke don't fix it I guess.


I've seen a lot of crazy things posted here, but that may take the prize!


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## z71mike (Feb 19, 2014)

BWAHAHAAAA


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## Rockjock (Feb 19, 2014)

Chris-PA said:


> I've seen a lot of crazy things posted here, but that may take the prize!


 yeah I know madness I am gonna port it advance the timing and do a muffler mod. Add a 660 carb and run it on go go juice that honey boo boo so loves.


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## o8f150 (Feb 19, 2014)

z71mike said:


> WT215 according to Scottso


yep,,, wt215,,, its a straight bolt up


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## Adirondackstihl (Feb 19, 2014)

Workin on mine right now.
Whats the trick to getting the wrap handle off?


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## treesmith (Feb 19, 2014)

Should come off easily, you'll have to drill holes for H+L screws in the cover but the idle already has one. Nothing hard as I remember. What muff mod did everyone do? I bent the fins open on the cover and drilled it 
out underneath. 

Sent from my GT-I9210T using Tapatalk


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## Tim Moffett (Dec 18, 2018)

Hi Folks - Hoping someone can help me here... I did the exhaust mod and installed a WT-215 carb on my MS170. It idles great but when I whack the throttle open, it bogs and dies. While the H screw adjust does seem to make a difference in the running of the engine, it does not get rid of the bog. It runs good until warm, so I am guessing that it's a rich bog? Any suggestions?


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## Adirondackstihl (Dec 18, 2018)

Did you pull the brass plug in the impulse circuit?


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## Adirondackstihl (Dec 18, 2018)




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## 1Alpha1 (Dec 18, 2018)

Slap a *MAGNUM* sticker on it and then you'll really have something to brag about.


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## Tim Moffett (Dec 18, 2018)

I saw that plug but couldn't tell if the OEM carb had a complete passage or not. I have not messed with it. What does that do, meter 'draw' on the high speed circuit


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## Tim Moffett (Dec 18, 2018)

1Alpha1 said:


> Slap a *MAGNUM* sticker on it and then you'll really have something to brag about.




Boom!


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## Adirondackstihl (Dec 19, 2018)

Tim Moffett said:


> I saw that plug but couldn't tell if the OEM carb had a complete passage or not. I have not messed with it. What does that do, meter 'draw' on the high speed circuit


It’s the impulse passage.
Pull the center plug and block the side one with sealant


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## Tim Moffett (Dec 19, 2018)

Thank you!


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## Tim Moffett (Dec 19, 2018)

Finished product - does this look right?


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## Adirondackstihl (Dec 19, 2018)

Tim Moffett said:


> Finished product - does this look right?
> 
> View attachment 691149


Exactly


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## Tim Moffett (Dec 19, 2018)

Cool thank you! The trail gods will be happy today!


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## Adirondackstihl (Dec 19, 2018)

Tim Moffett said:


> Cool thank you! The trail gods will be happy today!


Let me know how runs now


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## Henry E (Dec 20, 2018)

To get rid of the bog, you richen (back out/counter clockwise) the Low screw (closet to the cylinder). Not the High.
Generally you back out the low screw until you hear the revs just start dropping, then turn it back in just a hair.


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## Adirondackstihl (Dec 20, 2018)

Henry E said:


> To get rid of the bog, you richen (back out/counter clockwise) the Low screw (closet to the cylinder). Not the High.
> Generally you back out the low screw until you hear the revs just start dropping, then turn it back in just a hair.


Did you read anything here or just post based off the original post?


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## Schipp (May 17, 2019)

Adirondackstihl said:


> It’s the impulse passage.
> Pull the center plug and block the side one with sealant


What kind of sealant did you use to block the side hole? UPDATE: I read I can use “Plumbers sealant”!
Another question though! Do you have to pull that plug on all WT-215 carbs when you put it on the 170? Or are some of them already open there?
Ok, thanks!


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## Andrew Massey (Sep 6, 2019)

Any chance someone can throw up a link to where there getting there WT215's from, All of the ones i look at on ebay don't say WT215 but look correct, Like this: https://www.ebay.com.au/itm/CARBURE...340429?hash=item35e8c2b24d:g:1IIAAOSwWm5dRMZZ Can anyone confirm this is the correct carb?


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## Schipp (Sep 7, 2019)

Andrew Massey said:


> Any chance someone can throw up a link to where there getting there WT215's from, All of the ones i look at on ebay don't say WT215 but look correct, Like this: https://www.ebay.com.au/itm/CARBURE...340429?hash=item35e8c2b24d:g:1IIAAOSwWm5dRMZZ Can anyone confirm this is the correct carb?


Go to Amazon, type in wt215 carb!


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## Ando81 (Sep 12, 2019)

Hi all, I have just fitted a Chinese copy of the Walbro 215 carb to my Ms170. It took a bit of tweaking in the adjustment screws to suit my Australian conditions but the saw is a lot more throttle responsive. It was getting late and I didn’t want to disturb my neighbours by trying it in a piece of solid wood but I’m confident that it’ll be a big improvement. Muffler mod to follow soon [emoji1303]


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## Andrew Massey (Sep 12, 2019)

Ando81 said:


> Hi all, I have just fitted a Chinese copy of the Walbro 215 carb to my Ms170. It took a bit of tweaking in the adjustment screws to suit my Australian conditions but the saw is a lot more throttle responsive. It was getting late and I didn’t want to disturb my neighbours by trying it in a piece of solid wood but I’m confident that it’ll be a big improvement. Muffler mod to follow soon [emoji1303]


 can you please post a link to the carb you bought


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## Ando81 (Sep 12, 2019)

Andrew Massey said:


> can you please post a link to the carb you bought



Sure [emoji6] https://rover.ebay.com/rover/0/0/0?mpre=https://www.ebay.com.au/ulk/itm/183672301360


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## Huskybill (Sep 12, 2019)

Is it worth the upgrade?


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## Ando81 (Sep 12, 2019)

I haven’t put the saw into a solid piece of wood yet but it sounds much sweeter just revving it without load. Like someone posted earlier, it may be a bit harder to start without having the half choke option like the original carby but I think I can live with it. I hope to use the saw on Saturday so I will be able to share my findings then, stay “tuned” [emoji1787]


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## Huskybill (Sep 12, 2019)

Sounds a interesting read.


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## Andrew Massey (Sep 12, 2019)

Ando81 said:


> Sure [emoji6] https://rover.ebay.com/rover/0/0/0?mpre=https://www.ebay.com.au/ulk/itm/183672301360



Thank you, This was the exact carb I was looking at too, Look forward to seeing how you go, Whats the go with the choke as in what happens when you put it in the half choke position? its just in run?


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## Ando81 (Sep 12, 2019)

The choke seems to jump off the second notch and goes straight to run. I didn’t take a lot of time to look at it enough but I’m thinking that the choke flap lever is slightly different to original carb and pulls the start lever straight up to run instead of stopping half way. It might need further inspection on the weekend.


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## Andrew Massey (Sep 12, 2019)

All good mate just trying to get a mental picture of what happens, Sounds like its definitely worth it though! I was looking at the wt215 as my ms170 was bogging down at wot, But pulled the carb apart and cleaned it out and now its all good but is running slightly too rich and no longer pulls the rpms it did and cuts no where as fast so might buy one and throw it on just for the adjustability and tuning benefits!

Called the dealer near me and a genuine wt215 is $112.50, not worth it when I payed $150 for the saw


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## Ando81 (Sep 14, 2019)

Well after giving my setup a tune I tried it in some very damp greybox and it seemed to bog down a little. I had my 14” tungsten tipped chain so figured that it wasn’t a really practical test for it. I tried it in a piece of very dry ironbark with the tungsten chain and it performed well. I wouldn’t say a huge improvement in power but a small improvement. I actually got the choke to work on the half choke and it started up really well. I’ll try to get to the muffler mod and another tune tomorrow to see if anything changes.


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## ChuckRock (Jan 23, 2021)

treesmith said:


> Love my 170, modded the muff, fitted the walbro adjustable carb and advanced the timing, wears 12" .050 Stihl and it runs great. It gets battered as a chipper saw for an arb company and its not died yet
> 
> Sent from my GT-I9100 using Tapatalk


How much did you file off for the advance ? No issues with detonation I trust


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## Mike Kunte (Feb 4, 2021)

Hey, All!

So glad I found this thread! Based on its contents, I ordered an OEM Stihl W215 carb. I love my little 170, but have always found her slightly gutless. In general, I try to match the saw to the job, and use the smallest one possible. Can't wait to do the mods.
Also found this video on YT, in which the poster did 6 mods to his 170. Take a look:



Hope this helps!
Mike


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## Ando81 (Feb 4, 2021)

I’m definitely doing the side tensioner mod. I’ve done carby & muffler mod already [emoji1303]


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## Mike Kunte (Feb 4, 2021)

He


Ando81 said:


> I’m definitely doing the side tensioner mod. I’ve done carby & muffler mod already [emoji1303]


Hey, Ando81!!

How did the carby mod go? Did you also remove the brass plug, and fill the left hole? Yes, agreed! The first mod I did was the side tensioner - if I wanted to struggle with a fiddly little screw next to the bar, I would have bought a Husky!!!

Thanks,

Mike


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## cranman1951 (Feb 4, 2021)

Very interesting thread! The smallest Sthil I've used is a 230 and it was one of the handiest saws I've ever run.


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## Ando81 (Feb 4, 2021)

Mike Kunte said:


> He
> 
> Hey, Ando81!!
> 
> ...



That’s right, I had all of the tips from here how to prepare the new carb to suit my 170. It’s running great but I’ve tuned it to be slightly rich just to be safe. It goes really well.


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