# Stihl MS 170 bogging down, no power



## GerrySM (Jul 14, 2016)

I have big saws but now only use this small chainsaw because a back injury means I cannot handle the heavier ones.

MS170 is 2 years old, suddenly developed a bogging out problem in the middle of a cut. 


Muffler screen is clean.
Spark plug and chain are new.
Bar nose sprocket turns easily. 
Fuel is fresh and correctly mixed.
Fuel filter is clean.

My suspicion is contamination via the air intake







When I remove the cover (13), I find the upper surface of the filter (2) heavily contaminated (this is an aftermarket eBay filter, perhaps it is not sealing properly?). There is oily sawdust on part 4, and if I put my finger into the intake vent on 3, it comes out contaminated with fine, slightly oily sawdust as well. I found this a bit shocking, as this area is supposed to be pristine, right?

I cleaned it all out as best I could, but the contamination occurred again, and I'm worried that some of this gunk has got into the carb. The saw loses power and almost stalls in deep cuts now. (There is no way to alter the fuel mixture on this machine, btw).

Is my next step a carb cleanout? I hope none of this stuff has damaged the piston ....


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## GerrySM (Jul 14, 2016)

Someone reviewed these typical aftermarket air filters on Amazon like this:



> Filters are much too thin. Would take 2 to 3 together to work right. Even Stihl makes heavier filter to try and keep sawdust out of engine.



I suspect this is the problem for me too. The OEM filter did not allow sawdust through, but these did, because the edges do not seal properly (filter too thin to cause enough pressure against the cover at the edges).

I also saw this review on Amazon for a new MS170 carb:



> I replaced the original carb because *air leaked around the chintzy air filter* when the saw was new. It clogged the carb up with saw dust and I couldn't spray it out to where it would work right. Kept bogging down at full throttle. This new carb cured that issue.



So now I wonder ... new carb, or risk just getting a carb kit?


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## VinceGU05 (Jul 14, 2016)

does it run without air filter? if all good then yr filter is choking it.


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## GerrySM (Jul 14, 2016)

It runs fine with the new air filter I have inserted. It just bogs down in the cut.

I'm pretty sure the carb is fouled. Just want an opinion on what to buy:

*
Carb Kit? ($5 on eBay)
New carb? ($12-15 on eBay)
*


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## mountainlake (Jul 14, 2016)

I'd just take it apart and clean it. If that doesn't work a new carb. Steve


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## GerrySM (Jul 14, 2016)

Thanks Mountainlake, I'll do that


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## HarleyT (Jul 14, 2016)

Look at the fuel line closely. Look for cracks, also look for it to become soft and gummy.


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## CR888 (Jul 14, 2016)

Clean out the screen in carb like moutainlake suggests. Bet there is some crud in there. Probably don't even need a kit.


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## Chris-PA (Jul 14, 2016)

These kinds of carbs cannot hold a constant fuel/air ratio as air flow changes. So anything that causes a change in air velocity through the carb will change the mixture, but these carbs are non-adjustable. If the filter significantly changes the air flow, the mixture must change. 

The people who designed this thing with a nonadjustable carb knew exactly what kind of a cheese they were doing. That they sold it that way anyway shows they simply didn't give a crap about their customers.


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## GerrySM (Jul 14, 2016)

In all fairness to Stihl, I think I am to blame here for buying cheap-ass Chinese filters that are too thin to seal out the airborne sawdust. I am now using 2 of them at a time to create some sort of seal at the edges when the cover is put on and locked down onto them.


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## GerrySM (Jul 14, 2016)

Excellent aid to anyone looking to clean their MS170 carb:


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## sugarbush (Jul 14, 2016)

if particles are going into the carb through the air filter that won't plug up carb.


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## GerrySM (Jul 14, 2016)

sugarbush said:


> if particles are going into the carb through the air filter that won't plug up carb.



If you look at the messages I quoted above, you'll see that others have found the same issue. Where do you think the sawdust will go, just evaporate into thin air? They will plug the airflow or fuel flow, I will find out which today.


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## GrassGuerilla (Jul 14, 2016)

Might want to get a look at the P&C before you buy anything else. If enough chit went through the filter, where do you think it went? Quite possibly right on through.


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## Chris-PA (Jul 14, 2016)

GerrySM said:


> If you look at the messages I quoted above, you'll see that others have found the same issue. Where do you think the sawdust will go, just evaporate into thin air? They will plug the airflow or fuel flow, I will find out which today.


Fine sawdust is very unlikely to build up in the parts of the carb exposed to the intake air. It will go through the engine, possibly causing wear on piston and some carbon buildup.


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## TBS (Jul 14, 2016)

I had an 017 at work that would do the same but eventually just wouldn't start, I took the carb apart and cleaned it but had to throw it back together because more important things came up, sent it to a dealer who said it was dead, year or so later last month pulled the carb apart and found out needle valve lever didn't have enough bend to open the needle valve. Bent a hair and that little saw runs like a champ now.

As for the filter use oem or just go to the store and get a pack of green scotch bright pads because they cheaper, much stiffer, and filter as good as most aftermarket air filters. You can cut them to fit as well.


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## sugarbush (Jul 14, 2016)

the sawdust will go into the engine not into the passages of the carb. those passages are affected by what is in the gas tank. buy an adjustable walbro carb from ebay for about $15.00.


GerrySM said:


> If you look at the messages I quoted above, you'll see that others have found the same issue. Where do you think the sawdust will go, just evaporate into thin air? They will plug the airflow or fuel flow, I will find out which today.


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## GerrySM (Jul 14, 2016)

Ah hell, got inside the carb but while removing the little brass jet, which was screwed in _very_ tightly, the screwdriver slot on the jet just cracked under the torque pressure of my screwdriver, so I guess I'll have to buy a new carb anyhow. As far as I know, this little brass jet is not available separately.

One could almost say that these cheap little carbs are not made to be serviced, they are throwaway items; quicker and cheaper just to replace them. Got a new one on eBay for around $12 (can't see the advantages of buying an adjustable Walbro ... the unadjustable one I had was working great until recently).



> Fine sawdust is very unlikely to build up in the parts of the carb exposed to the intake air. It will go through the engine, possibly causing wear on piston and some carbon buildup



I had a look at the piston from the connection tube to the carb, seems unmarked and smooth. But there could still be damage in there, we'll see with the new carb.

If the new carb fixes things, it means dirty air can affect the carb. If not, then it suggests the machine is f*ed.


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## dugide (Jul 15, 2016)




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## GerrySM (Jul 15, 2016)

dugide said:


>



Yup, looking at the old carb, cannot see any dirt in it, so unless there was tiny debris in places I cannot see, I suspect the engine has been damaged by sawdust debris, which means the machine could be kaput.  I have to wait 2 weeks for the new carb to come from China, then I'll report back here.


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## TBS (Jul 15, 2016)

I'd really doubt it if the piston looks ok, my redmax sucked a bunch dust past the foam seal for the strato valves for quite a while but zero damage to engine.


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## GerrySM (Jul 15, 2016)

First pic shows dirty choke flap


Broken jet (actually known as "remote jet" on this diagram, part #65), before the break


gasket where carb attaches to engine


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## GerrySM (Jul 15, 2016)

One weird thing I noticed is that one of the nuts holding the carb to the engine was not tight; not exactly loose, but no effort required to turn it open. This could mean air was leaking past the gasket you see in the last pic above.... making the machine run lean, which of course means a loss of power. Hmmm.


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## Mattyo (Jul 15, 2016)

Have you pulled the muffler yet to look at the piston?


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## VinceGU05 (Jul 15, 2016)

GerrySM said:


> Excellent aid to anyone looking to clean their MS170 carb:



so hows yr fuel line? not soft and gummy like in the video?


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## GerrySM (Jul 15, 2016)

Mattyo said:


> Have you pulled the muffler yet to look at the piston?



That's next, but as I said the piston looks smooth through the carb-cylinder barrel.



VinceGU05 said:


> so hows yr fuel line? not soft and gummy like in the video?



No, firm and round. It's not the fuel line. We don't use ethanol in fuel here in Australia...


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## Chris-PA (Jul 15, 2016)

A non adjustable carb on a chainsaw is not a workable design, it's just junk - no matter what name is on the thing. These carbs cannot even hold a constant fuel mixture with changing air flow, let alone changes in temperature. They are not accurate enough to be non adjustable, and the people who produced this saw knew that. 

Provided the cylinder/piston is not scored, the loose carb bolt may have been a factor.


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## HarleyT (Jul 15, 2016)

GerrySM said:


> Yup, looking at the old carb, cannot see any dirt in it, so unless there was tiny debris in places I cannot see, I suspect the engine has been damaged by sawdust debris, which means the machine could be kaput.  I have to wait 2 weeks for the new carb to come from China, then I'll report back here.


You should have gotten a real one at your Stihl dealer for $21.49


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## GerrySM (Jul 15, 2016)

With muffler removed, here's the piston.




Good page on diagnosing piston damage


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## GerrySM (Jul 15, 2016)

HarleyT said:


> You should have gotten a real one at your Stihl dealer for $21.49



The one I bought is marked "Zama" just like the one I took out of the MS170. Here's a pic of it from the eBay listing:


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## Wood Doctor (Jul 15, 2016)

Chris-PA said:


> A non adjustable carb on a chainsaw is not a workable design, it's just junk - no matter what name is on the thing. These carbs cannot even hold a constant fuel mixture with changing air flow, let alone changes in temperature. They are not accurate enough to be non adjustable, and the people who produced this saw knew that.
> 
> Provided the cylinder/piston is not scored, the loose carb bolt may have been a factor.


I ran into this same problem with a non-adjustable carb somebody installed on an 025. The saw refused to idle down, settling in at no lower than 4500 RPM. I replaced it with an adjustable carb (both hi and lo setscrews), and the saw runs today like it was new.


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## HarleyT (Jul 15, 2016)

That seller is in Hong Kong, it will take a couple of weeks.


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## GerrySM (Jul 15, 2016)

Wood Doctor said:


> I replaced it with an adjustable carb (both hi and lo setscrews), and the saw runs today like it was new.



Regarding the people who suggest replacing the carb with a more advanced, adjustable carb: I do not think it is necessary. The machine performed well for the first 18 months with the OEM carb. I believe what has happened here is that the factory did not tighten the carb up properly, and over time the one nut became looser, allowing air to leak into the cylinder, making the machine run weak and lean. All I needed to do was tighten it up, but I never recognised it as the problem until too late — by then I had broken a jet in the carb.

This machine should be able to run perfectly even with the primitive OEM carb.

On another topic: does anyone have any tips for cleaning my aluminium (or "aluminum") muffler? It's pitch black with baked-on carbon. You cannot burn it off, the aluminium will melt (I think). I do have a heat gun though, if anyone thinks it's worth trying or has experience of heating up an aluminium muffler to decarbonise it. Ammonia would probably work, but ammonia will attack aluminium.


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## VinceGU05 (Jul 15, 2016)

just for ***** and giggles. blow out the old carby and pop it back on even with the cracked jet. (tight this time) and try again. ( might as well while you wait for new carby)

the muffler has like a galvanized coating. heat gun it will be fine but may kill the gal coating.


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## HarleyT (Jul 15, 2016)

It's not aluminum.


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## GerrySM (Jul 15, 2016)

VinceGU05 said:


> the muffler has like a galvanized coating. heat gun it will be fine but may kill the gal coating



Can I respray it afterwards with a gal paint?



HarleyT said:


> It's not aluminum.



I thought it was, I think I read it was somewhere....



> blow out the old carby and pop it back on even with the cracked jet



If I can only find that jet ....


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## HarleyT (Jul 15, 2016)

Here is one with a magnet stuck to it.


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## GerrySM (Jul 15, 2016)

D'oh! Should have thought of that....  

Would ammonia attack the gal coating?

Edit: apparently it will — from this page:



> *Cleaning Organic Contaminants from Galvanized Surfaces*
> 
> The AGA recently conducted a study to test which commercially available products are best at removing organic contaminants from galvanized steel. The following products did not damage the coating:
> 
> ...


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## VinceGU05 (Jul 15, 2016)

it may.. can paint it with black exhaust paint too.. just do a little test on the back of it. 
could open the muffler up a little if you want to help it along. i did this on mine just with a screwdriver.




some other good reads too.

http://www.arboristsite.com/community/threads/stihl-025-bogging-in-the-cut.164893/

http://www.arboristsite.com/community/threads/stihl-ms170-bogging-when-hot.247889/


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## HarleyT (Jul 15, 2016)

Put up a pic of your muffler, curious to see this residue..


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## GerrySM (Jul 15, 2016)




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## VinceGU05 (Jul 15, 2016)

i would just wipe it down with thinners or the like and repaint if you want.
i was thinking it was looking like this.


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## GerrySM (Jul 15, 2016)

VinceGU05 said:


> i would just wipe it down with thinners or the like and repaint if you want.



So there is no simple way to get a muffler back to the silver finish? I did do it once, but it involved a lot of hard work and even some wire brush work with the Dremel.



> i was thinking it was looking like this.



The inside looks a bit like that


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## HarleyT (Jul 15, 2016)

I'll sell you my shiny one for $5.....


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## GerrySM (Jul 15, 2016)

HarleyT said:


> I'll sell you my shiny one for $5.....



Yes, if you are in Australia and if it's with minimal shipping costs. Why are you selling it?


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## GerrySM (Jul 15, 2016)

For cleaning, oven cleaner would be ideal, wouldn't it? Except most oven cleaning products contain lye (caustic) and have the warning: "Due to highly alkaline nature of formulation, do not use on aluminium, copper,* galvanized,* plastic composition tile etc etc"


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## VinceGU05 (Jul 15, 2016)

wire brush it.. if it comes off good.. if not so be it.. silver frost paint over the top of it.


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## GerrySM (Jul 15, 2016)

VinceGU05 said:


> wire brush it.. if it comes off good.. if not so be it.. silver frost paint over the top of it.



Yep that seems sensible. I think I got most of it off last time with a dremel and wire wheel, see top left hand side one here:








Probably buggering up the galv coating though!


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## dugide (Jul 15, 2016)

didn't it have a screen?


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## GerrySM (Jul 15, 2016)

dugide said:


> didn't it have a screen?


Yes, but I have put it to one side. Not really needed in my situation, and just gets dirty and needs cleaning


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## dugide (Jul 15, 2016)

if you haven't cleaned it would you post a pic?


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## GerrySM (Jul 15, 2016)

It is not gummed up. I was long ago aware of looking out for a carboned up screen, this saw's screen was always fairly clean, a few brushes with a wire brush and good to go.


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## HarleyT (Jul 15, 2016)

Did you just put your location in your signature?


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## GerrySM (Jul 15, 2016)

Yup


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## GerrySM (Jul 16, 2016)

Actually I am thinking of using a home made soda blaster to clean the muffler. Here's what a soda blaster can do:



and they are dead easy to make yourself:


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## moondoggie (Jul 16, 2016)

Do you think an adjustable carb would help with your carbon situation? 18 months is not that long for a carb to last IMO


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## GerrySM (Jul 16, 2016)

Nah, I don't think my carbon buildup is that unusual.


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## moondoggie (Jul 16, 2016)

I cut 350 cords in 3 years with my 445. Zero carbon buildup. That carb lasted four years on a "home owner"saw.

These guys recommending an adjustable carb really want to help you. They know what they are talking about. Stihl is hoping you just throw that saw away and buy another one.


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## GerrySM (Jul 16, 2016)

Thanks, but you'll see similar carbon buildups on MS170 saws all over the net if you do a google search. You'll also see it on more expensive saws that do have adjustable carbs. I think mine was performing to spec, and with a new (properly tightened up) carb it should run fine.

BTW, I also have carbon stains on my 455 Husky muffler, and that is after careful adjustment of that carb. If you have zero carbon on your muffler you are probably running too lean.


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## moondoggie (Jul 16, 2016)

GerrySM said:


> Thanks, but you'll see similar carbon buildups on MS170 saws all over the net if you do a google search. You'll also see it on more expensive saws that do have adjustable carbs. I think mine was performing to spec, and with a new (properly tightened up) carb it should run fine.
> 
> BTW, I also have carbon stains on my 455 Husky muffler, and that is after careful adjustment of that carb. If you have zero carbon on your muffler you are probably running too lean.


OK thanks for the tip.


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## Chris-PA (Jul 16, 2016)

Curious why they bother with adjustable carbs on their more expensive saws.


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## sugarbush (Jul 16, 2016)

don't know why someone with your chainsaw expertise bothers asking for help.


GerrySM said:


> Thanks, but you'll see similar carbon buildups on MS170 saws all over the net if you do a google search. You'll also see it on more expensive saws that do have adjustable carbs. I think mine was performing to spec, and with a new (properly tightened up) carb it should run fine.
> 
> BTW, I also have carbon stains on my 455 Husky muffler, and that is after careful adjustment of that carb. If you have zero carbon on your muffler you are probably running too lean.


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## GerrySM (Jul 16, 2016)

Guys, I have not found that an adjustable carb makes that much of a difference on a 2-stroke engine. I had my carbs on my bigger saws professionally adjusted by 2 different small engine workshops, and their mufflers still got dirty.

Please note that since I have lost power on my machine, it's actually been burning white (lean). The inside of the muffler is grey and clean, and the spark plug looks very clean (too clean). This just supports my theory that the loose bolt on the carb mounting was allowing air in. An adjustable carb will not fix this.


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## Chris-PA (Jul 16, 2016)

GerrySM said:


> Guys, I have not found that an adjustable carb makes that much of a difference on a 2-stroke engine. I had my carbs on my bigger saws professionally adjusted by 2 different small engine workshops, and their mufflers still got dirty.
> 
> Please note that since I have lost power on my machine, it's actually been burning white (lean). The inside of the muffler is grey and clean, and the spark plug looks very clean (too clean). This just supports my theory that the loose bolt on the carb mounting was allowing air in. An adjustable carb will not fix this.


It's possible that the bolt was loose enough to cause it, but you will find that out. 

Really though keeping the muffler spotless is not the goal of tuning - keeping the engine healthy and producing good power is. There is no real hope of keeping the muffler clean with a fuel system than goes so rich it misfires with only a slight lift and rpm increase.


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## abikerboy (Jul 16, 2016)

Keep in mind also that they do make different jets for these carbs. I know there is a high altitude jet and a low altitude jet. Don't know if they're others or not. My dealer and I were talking about these carbs a while back, and that's how I learned about the jets. When the saw leaves the factory, they jet it for whatever part of the country that it will be sold in. When you get your new carb, and especially with it coming from another country, you may have to buy a different jet for it. That is the only way to adjust these carbs, and that only changes the high side. You're pretty much stuck with whatever you get on the low side. When the time comes for carburetor service on my MS170, I'm going to put an adjustable one on it and call it a done deal. Not worried about it right now though as it runs pretty good with the stock one.


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## GerrySM (Jul 16, 2016)

abikerboy said:


> When the time comes for carburetor service on my MS170, I'm going to put an adjustable one on it and call it a done deal.


Ah well, for a few dollars extra I should have bought the adjustable, but too late now.


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## abikerboy (Jul 16, 2016)

GerrySM said:


> Ah well, for a few dollars extra I should have bought the adjustable, but too late now.


Don't get too worried yet, as there may be a pretty good chance that it will work right off the bat. And even if you do have to rejet, those jets shouldn't cost too much.


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## Chris-PA (Jul 16, 2016)

abikerboy said:


> My dealer and I were talking about these carbs a while back, and that's how I learned about the jets. When the saw leaves the factory, they jet it for whatever part of the country that it will be sold in.


I'd be extremely skeptical about this claim from your dealer. These are the very cheapest of mass produced saws, and I doubt they have any idea where they are going when they are built. If the carbs are jetted differently then they would have different part numbers, so someone who knows Stihl can easily verify it.


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## abikerboy (Jul 16, 2016)

Chris-PA said:


> I'd be extremely skeptical about this claim from your dealer. These are the very cheapest of mass produced saws, and I doubt they have any idea where they are going when they are built. If the carbs are jetted differently then they would have different part numbers, so someone who knows Stihl can easily verify it.


I'm really not sure if that is so, or not. I haven't had any carb problems with mine, so I don't even know if the jet is removable. It just came up in conversation with him. I would really like to know if that is true.

Edit: The ipl does show fixed jet 0.45 part#1130-121-5604 and high altitude fixed jet 0.42 part#4137-121-5601


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## GerrySM (Jul 17, 2016)

I bought a Harbor Freight style sand blaster today (from the Australian store supercheapauto.com.au on a special) and used it on the muffler, using only sodium bicarbonate. *Wow! Looks brand new*. I will spray it silver and post pics in a few days. Meanwhile, I can highly recommend one of these units to y'all. It just revolutionises cleaning and rust removal.


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## GerrySM (Jul 17, 2016)

abikerboy said:


> Edit: The ipl does show fixed jet 0.45 part#1130-121-5604 and high altitude fixed jet 0.42 part#4137-121-5601



I remember looking into this years ago, and the info I got then is that most saws, Huskies specifically, are jetted/adjusted from factory for sea level. I'm at 450m (1500ft) and that is still considered low altitude (only just), so no re-jetting required (although it would be nice if I could run a little bit leaner, I admit). That's probably why I am seeing a little carbon building up, when it is running normally. Could I fix this by going from 50:1 to 60:1, or 70:1? Or are carb settings and fuel mixtures different creatures entirely?

I think you have to get up over 600m/1800ft to justify re-jetting these units, from memory (could be wrong, will check if you push me)


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## mountainlake (Jul 17, 2016)

If you run at close to the same temperature all year you could get by with a non adjustable carb, over here when I have a carb adjusted right for the winter -5 to 15 above F the saw will be pig rich when it gets up to 80 F. Steve


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## GerrySM (Jul 19, 2016)

Is there supposed to be a gasket between the muffler and the body on the MS170? Mine does not have one and the dealer says it does not come with one .... all my other saws have had one.

Can't find the relevant parts diagram.


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## VinceGU05 (Jul 19, 2016)

nope .. doesnt have one.


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## GerrySM (Aug 5, 2016)

New Chinese carb made no difference, in fact it ran worse. I had to wind back the idle speed to the lowest setting and still the chain was advancing. They'd sold me a carb using a listing that had a picture of a Zama carb, but when I got it I found it was a generic carb, a lookalike  , so I started a claim on eBay and got the money refunded. 

Then I made the belated but fortunate discovery that the saw was on _*the last day*_ of its 2 year domestic use warranty, so I rushed it in to the dealer (d'oh!) 

Dealer found that the seals on the original carb had deteriorated allowing air in and making it run too lean. I did not quite understand the explanation over the phone, will speak to them more when I pick it up. It's not the gasket he's talking about, but some sort of seal on a hole/s drilled in the carb by the manufacturer for some sort of reason. Maybe he's talking about a diaphragm? They also replaced the tiny brass jet I broke and then lost.

They tell me it's running great now. 

No charge. Phew!


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## rocketnorton (Aug 6, 2016)

Nathan lassley said:


> As for the filter use oem or just go to the store and get a pack of green scotch bright pads because they cheaper, much stiffer, and filter as good as most aftermarket air filters. You can cut them to fit as well.



felt, ftw.
scotchbrite not only wont filter fine stuff, it does come apart. will polish up the piston when it does. just my $.02.


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## GerrySM (Aug 11, 2016)

Ok, final update on the carb saga.

Dealer technician showed me inside a carb exactly what happened. The sealant on the welch plug had deteriorated allowing air to be sucked. The sealant runs around the edge of the welch plug, about 1mm thick, barely visible.

He replaced the plug and sealant, and it runs fine now.

He says a lot of new, cheap chainsaws sold at Bunnings (Australia's Home Depot) have this problem due to sitting in a hot warehouse for a long time. The sealant can go. He has them coming in for this repair frequently, right after they are bought from Bunnings..

This is not a repair a home handyman can do easily. You need a special punch (and a special sealant, and a very tiny applicator) to get a new Welch plug back in.

He did not know why the new Chinese carb did not improve the situation. Moral of the story: don't buy Chinese carbs off eBay.


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## blsnelling (Aug 11, 2016)

sugarbush said:


> if particles are going into the carb through the air filter that won't plug up carb.





sugarbush said:


> the sawdust will go into the engine not into the passages of the carb. those passages are affected by what is in the gas tank.


This is true. Any saw dust will simply pass through the venturi of the carb. There's nothing to draw them into carb orfices as fuel is coming out of those.



HarleyT said:


> You should have gotten a real one at your Stihl dealer for $21.49


Definitely.

Glad you got it running right. BTW, a welch plug is simple to remove and replace. Drill a small hole in it and remove it with a wood screw. Install it with a flat punch. Sealant should not be required, but nail polish can be used.


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## mountainlake (Aug 11, 2016)

Where is the real one from Stihl made. Steve


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## GerrySM (Aug 11, 2016)

> Where is the real one from Stihl made. Steve



Zama is owned by Stihl and made in China. That still does not mean you can buy a generic Chinese carb on eBay and expect to get anything like the same quality.


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## rynosawr (Aug 12, 2016)

I rarely ever say anything like this, but I think it is deserved.


Rant/

There are now four pages of this train-wrecked thread wasted on trying to help you out by the good members here, and it is obvious that you spent more time on your avatar than you did reading any of the threads on this forum.

Why come to one of the best forums on chainsaws to ask for advice and take none of it? Seriously?

You bought a crappy aftermarket Chinese tissue air filter for an MS170? Really? was ~$7 at the dealer just too steep for you?

Couldn't just wash the old dirty one out with good degreaser and let it dry real good?

Your muffler gets carboned up bad? So run a higher quality gasoline with a synthetic 2 stroke premium mix oil like Stihl ultra or Husky XP at 50:1. Running cheap, crappy 2 stroke mix oil and bottom rung gasoline causes carbon buildup, especially if the carb is non-adjustable, which leads me to:

Couldn't get the one screw Chinese carb to work? Sounds suspicious to me, I have bought and used over 20 of these cheapie Chinese aftermarket carbs on all different models without a single issue. They have left hand threads on the one screw carbs, and you usually get them to adjust correctly at 2-3 turns out from bottomed. You should have bought the adjustable carb as advised, of course you would have just argued with all who advised you on how to tune it properly as well.

In the end, you took your FAIL to the dealer and let them fix it for you after you screwed with it and tampered/damaged the carb jet. That dealer is a saint and you should never try to work on your saw again. Why didn't you take it to the dealer in the first place? Always just take it to the dealer. Some people just aren't talented mechanically or can open their ears to good advice; just don't ask for help that you don't intend to utilize and can't fathom why someone would advise it.

This is why many members quit helping new guys on forums.... 2 strokes are finicky and tough to tune and fix at times, so you will get different advice from many, but all are only attempting to help you solve your frustration by giving advice of what they did in what they think was a similar situation.


In the end....

Bless your heart.


/rant


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## GerrySM (Aug 12, 2016)

rynosawr said:


> There are now four pages of this train-wrecked thread wasted on trying to help you out by the good members here, and it is obvious that you spent more time on your avatar than you did reading any of the threads on this forum.



I made my avatar several years ago. I see you have never bothered with one (too complex for you?), but you're more than willing to spend time flaming people, which is a much better investment of your time, so kudos to you for great time management. It's all about priorities, I hear. 



> Why come to one of the best forums on chainsaws to ask for advice and take none of it? Seriously?



Interestingly, none of it would have solved my problem. Nobody mentioned welch plug sealant, or even welch plugs. Since the techs tell me this is a common cause of saws bogging down in cuts, it will be a very useful thread for many other people, I reckon. Of course, this is not a useful thread to those who regard anything exploratory or open-ended as a "train wreck". For you it's either:

take lessons at the feet of the Arboristsite Masters of the Chainsaw Universe, 
or get lost
Right? 



> You bought a crappy aftermarket Chinese tissue air filter for an MS170? Really? was ~$7 at the dealer just too steep for you?



Er no. If you actually read the thread and engaged tiny brain before loud mouth, you'd have seen that the carb was sold to me as a "Zama", although it turned out not to be a Zama when it arrived. That's why eBay refunded me.



> Couldn't just wash the old dirty one out with good degreaser and let it dry real good?



In your parallel universe, a good washout would have fixed the seals on the welch plug. In everyone else's universe, not. 



> Your muffler gets carboned up bad? So run a higher quality gasoline with a synthetic 2 stroke premium mix oil like Stihl ultra or Husky XP at 50:1. Running cheap, crappy 2 stroke mix oil and bottom rung gasoline causes carbon buildup, especially if the carb is non-adjustable



My fuel and oil are _excellent_ quality. Any other helpful suggestions?



> Couldn't get the one screw Chinese carb to work? Sounds suspicious to me



Perhaps you should speak to the Stihl tech then, because he couldn't get it to work either. I still have it. If you are prepared to pay for shipping, I'll send it to you and you can futz with it to your heart's content. 



> You should have bought the adjustable carb as advised



Or: spend nothing and have the carb fixed under warranty, which was much smarter. 



> In the end, you took your FAIL to the dealer and let them fix it for you after you screwed with it and tampered/damaged the carb jet.



Wrong. I learned a lot from the whole process. I know much more about carbs now, and the internal workings of this chainsaw. That is worth a lot to me. And the tech told me that those jets break very easily, and that you have to have a screwdriver that fits the head of the jet very precisely (length and width) or it will break, which is another gem of info I am adding to this thread for other readers facing the same issues. (Aboristsite Masters of the Chainsaw Universe are free to disregard this info)



> Why didn't you take it to the dealer in the first place?



I had no idea it had a 2 year domestic use warranty. Most items I buy have a 1 year warranty. So sue me.



> Some people just aren't talented mechanically or can open their ears to good advice; just don't ask for help that you don't intend to utilize and can't fathom why someone would advise it.



Thanks for the insults. I have a few choice ones for you too, but I'll hold my tongue. I think I did pretty well, considering it was the first time I've got into the guts of a 2 stroke engine. I learned a lot, and would do it all again.



> Bless your heart.



Phuck you very much.


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## SEAM (Aug 12, 2016)

The dealer really is a saint. Usually warranty expires the moment anyone not qualified messes with the product.
I am really glad I didn't waste any time here...


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## GerrySM (Aug 12, 2016)

SEAM said:


> I am really glad I didn't waste any time here...



D'oh! Too late


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## SEAM (Aug 12, 2016)

Time to buy a new saw - warranty's over


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## GerrySM (Aug 13, 2016)

SEAM said:


> The dealer really is a saint. .... Time to buy a new saw - warranty's over



Final note about this: while I should have been aware the saw was still under warranty, the "saintly" dealer also has to bear some blame here. I emailed him a month ago telling him I had a problem and asking what carb model to buy for replacement. He looked in his records and reported to me that I had not brought it in for a service, and it may simply be a service issue. I did not think so, since I had done all the things that are done in a service (new spark plug, general clean up etc). Now when he checked my saw's record, *he would have seen that the saw was still under warranty*, and should have simply told me to return it under warranty. That's why he agreed to fix it despite the fact that I messed with it. _He erred in not informing me of the warranty in favor of getting me to pay for a service_, and when I became a bit annoyed about that —when the new Chinese carb failed and I discovered that the saw was still under warranty— he bent over backwards to look after me. The last thing he wants is for a customer to report this sort of thing to Stihl. Stihl dealerships are highly prized and can be lost if there is any whiff of impropriety. Hope this clears up the "saint" issue.


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