As I was at a pawn shop today, I ran into an older fellow that has this same exact chainsaw, and, brought it in to put a new carb on it. He was unsure of what to do and I told him I do small engine repair and he sent me to work. The carb kit came with an intake boot, and, little did I know what I was getting into with that. He wanted the new lines and intake boot and all installed, so I took it home and will take it to my shop tomorrow. I would suggest inspecting that intake boot, but (spoiler alert) you will need to remove the entire engine to do so from the main plastics. I got down to the clutch assembly, which, once removed, you can then remove the engine. Hope this helps!! Love your videos!!
I had a similar problem with my chainsaw. It turnout that the fuel line had a crack but it was in in tank just below the grommet. The carb was sucking in air and fuel
@@HomeGaragechannel Rule #1 is always start at the beginning. Never assume that someone else’s previous repair was done correctly. That can have you chasing your tail for quite some time. A tiny nick, split, or a loose fuel line can give you fits. Replace the fuel filter and lines and don’t look back. Just because a part is new doesn’t mean it’s good.
try adjusting the rocker arm height, it worked for me in a brand new ms170 that was bogging down when squeezing the throttle, moving the rocker arm up it will deliver more fuel to the engine, it may work for you too
I'd change the plug to what it calls for, NGK BPMR7A, not use HIPA plugs. Change the fuel line and filter. Get an OEM carburetor as THAT model uses a cheap carburetor. Stihl sells them for around $20. But, honestly, I think it's the plug being bad. I've run into that quite a bit honestly. If changing everything doesn't work, then it needs a new coil which isn't cheap for the OEM Walbro coil it needs. The MS170-180 use duckbills as vents in the oil and fuel tanks FYI.
You can remove the periscope from the original carb and put it on the new carb. I have done it lots of times. My guess is tank vent. However you can adjust the Stihl carb, but you will need a very small torx bit or jewelers screwdriver. There are very small torx bit holes in the adjustment holes, which you can adjust like most other saws. I have a brand new ms 170that I found to me turning over 14,000 RPMs. I backed out the high jet a quarter of a turn and dropped it down to a respectable and safe 13,030 RPMs. I had to use the smallest jewelers screwdriver that I have. It must be a #1 or #2 torx bit slot in the adjustment hole.
i would take off the muffler and check the exhaust port if its blocked it can cause these kinds of problems and can also give an artificially high compression reading
Lol. I just took this type of carb apart for the first time. That spring is a pain in the ass. I took the carb apart at the kitchen table to make sure I wouldn't lose anything.
My next thing to change would be the spark plug, i’ve had the same symptoms on a Honda mower engine & i was sure it was fuel related but instead it was a faulty spark plug.
Sounds like lean running so either carb or a vacuum leak. Non-adjustable carbs are a BIG no no to me but that's what we have to put up with a lot. I'll get an adjustable if I can find one if I'm keeping the machine. If not, it might go on down the road. I don't have enough hair left to leave it on a rock because of banging my head on it trying to figure something out that can't be manipulated. The 261 has instructions on how to readjust the carb if it gets off kilter BUT it's commercial grade and not entry level. Battery stuff would be their way to go. BLESSINGS
Always replace the fuel filter, there cheap. Check for leaks from the carb. Never buy a cheap aftermarket, unless you have to of course. You can also pull the fuel filter and check for leaks that way also.
Seems to me like if the fuel filter is clean and line is good, it's getting unmetered air from somewhere. Crankshaft seals, case seals or intake maby? After saying that, is the metering lever set too low? Also worth trying it with the fuel cap loose to eliminate the possibility of a bad vent. Thanks for sharing👍🏻 look forward to hearing what the issue ended up being!
One thing I have learned with Stihl products they like NGK spark plugs you can’t really use any other spark plug don’t know why but that’s one thing I would replace on that saw
If it is not the carb it is maybe a leak in the crank case i had this problem on a stiehl Av024 and i seached for hours There are two sealing rings on each side of the crank case. To test it block the intake the exaust and putt 0,5 to 0,8 bars of ptressure throug the spark plug opening
@@HomeGaragechannel yes but it is easy to test with pressure That seal has not to bee that thight You can although apply pressure and vacuum just with your mouth. That would be enough.
Whew. After reading all the suggestions and your replies I am left with a bad Goer. Lets see. It does not appear to be fuel blockage, air leaks, muffler blockage and not the coil. I wonder if it could be a grounding issue with the kill wire is all I am left with.
that's a good idea, and I appreciate you going thru the information that's available before coming up with an idea. You're efforts are very welcome D Butler
Its sucking air. Either the intake boot, cylinder gasket, or crankshaft seals might be letting air in. Take the top cover off, have some carb cleaner or WD40 or whatever, start it and spray around the intake boot. If it doesn't change the way it runs, it'll probably die out. Start it again and spray around the intake gasket. The seals don't really go bad unless its old. I want to say its the carb because I saw a small brass jet in there. I'd hate it to be rubbish under those oblong welch plugs. If it's not sucking air, I'd go straight for the jet. Make sure your rocker arm is flush with the carb body (diaphragm mount).
I recently found out that the fuel injected V twin Kawasaki engine being sold on commercial grade equipment is currently being recalled because they’re catching on fire. Something to do with the high pressure fuel line rubbing against moving parts and starting leaks that can lead to a fire.
As always another excellent very detailed video! Thank you home garage you’ve helped me a lot! But honestly I would probably start with a cheap aftermarket carb then see what happens..
You’re the one expected to fix it because when it’s owner asked you, you said yes! 😁 In my experience, if you do a good job at a fair price, you’ll be getting the broken equipment first instead of ‘Mr. Can’t Fix It’ from thereafter, so you probably won’t have to clean up someone else’s mess anymore!
I can say from experience the MS170 is definitely one of my least favorite chainsaw that Stihl makes. For the power and reliability it's might be better to buy a different brand if you buy a new chainsaw like a Poulan, craftsman or even a Ryobi. But i guess you get what you pay for.
I bought a ms251 a few years ago. Brand new from authorised dealer. The bar got badly scorched on first use as the oil wasn't getting through to the chain. Took it back and rectified. But still have a badly scorched bar.
good possibility but stopping after less than a minute of running, and being able to start again, only to have it again, would make it a very special spark plug indeed
I hate 2 cycle… I would look further… On those cheap kits I never trust the spark plug and have mixed results with fuel filters. I hate 2 cycle You also had someone else work on the machine could have messed up fuel line and filter during install. I hate 2 cycle
Nothing to do with the carb it’s sommet in the tank not getting enough fuel the carbs working running fine just might be blocked in the air filter or fuel filter or lines I’d strip it all down start again new everything in
I would check the fuel tank next. The fuel filter might be blocked or the vent line or fuel lines might be kinked.
You're headed in the right direction !
@@HomeGaragechannel honestly from the way it ran i would have thought of a crank seal leaking air into the crank case
As I was at a pawn shop today, I ran into an older fellow that has this same exact chainsaw, and, brought it in to put a new carb on it. He was unsure of what to do and I told him I do small engine repair and he sent me to work. The carb kit came with an intake boot, and, little did I know what I was getting into with that. He wanted the new lines and intake boot and all installed, so I took it home and will take it to my shop tomorrow. I would suggest inspecting that intake boot, but (spoiler alert) you will need to remove the entire engine to do so from the main plastics. I got down to the clutch assembly, which, once removed, you can then remove the engine. Hope this helps!! Love your videos!!
thank you for the information Flaming Fox Productions
I had a similar problem with my chainsaw. It turnout that the fuel line had a crack but it was in in tank just below the grommet. The carb was sucking in air and fuel
I wish this was the situation but the fuel line was already replaced before I got it.
@@HomeGaragechannel Rule #1 is always start at the beginning. Never assume that someone else’s previous repair was done correctly. That can have you chasing your tail for quite some time. A tiny nick, split, or a loose fuel line can give you fits. Replace the fuel filter and lines and don’t look back. Just because a part is new doesn’t mean it’s good.
What liquid do you have in your rejuvenation bath for the diaphragms?
that's brake fluid
AT-205 would be my bet
check the intake boot, impulse, and fuel line.
This
thank you Matt Fleming
try adjusting the rocker arm height, it worked for me in a brand new ms170 that was bogging down when squeezing the throttle, moving the rocker arm up it will deliver more fuel to the engine, it may work for you too
ah, you make good point.
how much fuel is in the tank? Maybe there isnt oxygen flow in the tank , mine got the same or very similar behaviour , definitely lack of fuel .
thank you Czecher86
my guy, at this point you should open a small engine repair shop
I know right!
I'd change the plug to what it calls for, NGK BPMR7A, not use HIPA plugs. Change the fuel line and filter. Get an OEM carburetor as THAT model uses a cheap carburetor. Stihl sells them for around $20. But, honestly, I think it's the plug being bad. I've run into that quite a bit honestly. If changing everything doesn't work, then it needs a new coil which isn't cheap for the OEM Walbro coil it needs.
The MS170-180 use duckbills as vents in the oil and fuel tanks FYI.
thank you for the information
Considering all the junk in the carb I'd be looking for a clogged or broken fuel line and filter. Also check the tank for crud and the vent tube.
that's very possible
You can remove the periscope from the original carb and put it on the new carb. I have done it lots of times. My guess is tank vent. However you can adjust the Stihl carb, but you will need a very small torx bit or jewelers screwdriver. There are very small torx bit holes in the adjustment holes, which you can adjust like most other saws. I have a brand new ms 170that I found to me turning over 14,000 RPMs. I backed out the high jet a quarter of a turn and dropped it down to a respectable and safe 13,030 RPMs. I had to use the smallest jewelers screwdriver that I have. It must be a #1 or #2 torx bit slot in the adjustment hole.
Could there be a crack on the intake boot?
it's possible, but this saw has not been ran, all that much.
i would take off the muffler and check the exhaust port if its blocked it can cause these kinds of problems and can also give an artificially high compression reading
good idea!
9:03 why there a needle bearing on the back of the carburetor
that's how they close passages
Lol. I just took this type of carb apart for the first time. That spring is a pain in the ass. I took the carb apart at the kitchen table to make sure I wouldn't lose anything.
you made the right choice in locations
What chemical is in the rejuvination bath?
it's brake fluid
My next thing to change would be the spark plug, i’ve had the same symptoms on a Honda mower engine & i was sure it was fuel related but instead it was a faulty spark plug.
that's very interesting
I am wondering if it isn't the spark plug or the coil
it's possible
The stihl ms 170 has adjustments scruws but the are hidden very well
As others have said, check the rest of the fuel system, if that’s not the problem, it could be an air leak somewhere
that's good advice, thank you Hester's Workshop
I have a stihl trimmer doing the same think and even when I just the carb it still dose the same sort of thing
unfortunately you and I are in the same boat.
Because you know what your doing an you respect everyone's equipment that's why I like 👍 you so much
I appreciate the Kenneth Drown, I try my best.
Sounds like lean running so either carb or a vacuum leak. Non-adjustable carbs are a BIG no no to me but that's what we have to put up with a lot. I'll get an adjustable if I can find one if I'm keeping the machine. If not, it might go on down the road. I don't have enough hair left to leave it on a rock because of banging my head on it trying to figure something out that can't be manipulated. The 261 has instructions on how to readjust the carb if it gets off kilter BUT it's commercial grade and not entry level. Battery stuff would be their way to go. BLESSINGS
this one is going to be tricky for sure.
Always replace the fuel filter, there cheap. Check for leaks from the carb. Never buy a cheap aftermarket, unless you have to of course. You can also pull the fuel filter and check for leaks that way also.
ah,, you're headed in the right direction!
Looking forward to your follow-up video. I won't spoil the ending.
thank you for that, the answer is just weird but it might make since to those that know.
Did you hear it idle up before it shut down. This tells me it is a cue delivery problem. Tank vent,fuel line, etc.
yep you are correct, as it runs out of fuel, It will idle open right before stopping
Seems to me like if the fuel filter is clean and line is good, it's getting unmetered air from somewhere. Crankshaft seals, case seals or intake maby? After saying that, is the metering lever set too low? Also worth trying it with the fuel cap loose to eliminate the possibility of a bad vent.
Thanks for sharing👍🏻 look forward to hearing what the issue ended up being!
ah, you're definitely going in the right direction
One thing I have learned with Stihl products they like NGK spark plugs you can’t really use any other spark plug don’t know why but that’s one thing I would replace on that saw
yes agreed
Iv seen this problem in saws with a blocked tank vent or impulse line.
both good idea.
I would check for an air leak. The crank seals on the 180 are not the best and l would assume the 170s are the same sadly. Good luck!
that would be a good idea.
If it is not the carb it is maybe a leak in the crank case i had this problem on a stiehl Av024 and i seached for hours
There are two sealing rings on each side of the crank case. To test it block the intake the exaust and putt 0,5 to 0,8 bars of ptressure throug the spark plug opening
that's a lot pressure for testing for a leak on a seal that typically only see vacuum.
@@HomeGaragechannel yes but it is easy to test with pressure
That seal has not to bee that thight
You can although apply pressure and vacuum just with your mouth. That would be enough.
Whew. After reading all the suggestions and your replies I am left with a bad Goer. Lets see. It does not appear to be fuel blockage, air leaks, muffler blockage and not the coil. I wonder if it could be a grounding issue with the kill wire is all I am left with.
that's a good idea, and I appreciate you going thru the information that's available before coming up with an idea. You're efforts are very welcome D Butler
Ive had this happen on a customers saw, unscrew the idle speed screw, i dont know why, but it worked.
really? that's an interesting idea. thanks
I would get an adjustable carburetor for it. If it continues to run lean then a pressure test is in order..
good idea, thank you Joe W.
I like a challenge. I would keep digging for the problem.
me too!
Its sucking air. Either the intake boot, cylinder gasket, or crankshaft seals might be letting air in. Take the top cover off, have some carb cleaner or WD40 or whatever, start it and spray around the intake boot. If it doesn't change the way it runs, it'll probably die out. Start it again and spray around the intake gasket. The seals don't really go bad unless its old. I want to say its the carb because I saw a small brass jet in there. I'd hate it to be rubbish under those oblong welch plugs. If it's not sucking air, I'd go straight for the jet. Make sure your rocker arm is flush with the carb body (diaphragm mount).
that's a pretty good possibility
0:32 Mines the opposite can’t stop from flooding
have you considered replacing the carb?
@@HomeGaragechannel next step
I rebuilt it. new diaphragm ,needle , and gaskets still flooding
carb is it then
I'd keep digging into the fuel system.
thank you TK Mad.
I recently found out that the fuel injected V twin Kawasaki engine being sold on commercial grade equipment is currently being recalled because they’re catching on fire. Something to do with the high pressure fuel line rubbing against moving parts and starting leaks that can lead to a fire.
I'll have to look that up, but yes that's big issue if it's true.
Man I wish I could give you advice but I’m here to learn 😂. Can’t wait to till the next video
lol.. I appreciate it man, don't worry, I typically get them fixed either way.
Sounds like you have an intake leak by chance on the Kranks side or something
it's always possible
I guess I would keep digging os i Could Look for otherproblems Thank you for the video
no problem
As always another excellent very detailed video! Thank you home garage you’ve helped me a lot!
But honestly I would probably start with a cheap aftermarket carb then see what happens..
thank you Chris's garage and that's a very good idea.
@@HomeGaragechannel thank you home garage!
Diaphragm
Sounds like it's not getting fuel
Try another carb and check fuel line
Hey bro what's up? I would personally keep checking the fuel system to see if I can figure out the problem.
yep that's the plan, thank you Ramadin Sookhoo.
My guy, people remove it cause of blockages, like a generator. And most people don't know how to clean it
thanks
Non adjustable jets are a requirement of EPA. Since this is not a Strato saw EPA requires non-adjustable carbs to pass their emissions tests.
I see
i,d check out the fuel tank and fuel lines as they might be clogged and kinked etc.
you're headed to the right direction!
@@HomeGaragechannel for sure mate and never hard to look into etc.
I wood do à pressure test on the carb and the chainsaw to see if there is a leaking gasket somewhere
that's a good idea.
Hey mate, Great vid. Yeah if they wern't waing on it and i wasn't too busy, i would dig further you never know what you may learn. Cheers
that's the plan thank you Aussie nebula
You’re the one expected to fix it because when it’s owner asked you, you said yes! 😁 In my experience, if you do a good job at a fair price, you’ll be getting the broken equipment first instead of ‘Mr. Can’t Fix It’ from thereafter, so you probably won’t have to clean up someone else’s mess anymore!
you make a great point
I wouldnt soak the diaphragm in brake fluid because it could expand.
thank John Evans
I can say from experience the MS170 is definitely one of my least favorite chainsaw that Stihl makes. For the power and reliability it's might be better to buy a different brand if you buy a new chainsaw like a Poulan, craftsman or even a Ryobi. But i guess you get what you pay for.
I appreciate the insight
I bought a ms251 a few years ago. Brand new from authorised dealer. The bar got badly scorched on first use as the oil wasn't getting through to the chain. Took it back and rectified. But still have a badly scorched bar.
I think it gets some extra air from somewhere.
that's a good possibility
Tank vent? Also I wouldn't trust that spark plug, Hipa makes ok replacement carbs but spark plugs, probably not so much.
Yes the tank vent might be an issue. Not sure about the spark plug
I will take the muffler off and check to see if the port is partially plugged. 🤔🤔
good idea, thank you RayFpv!
I would keep digging. Mick's mowers uses wd40 to clean carbs and he says it works great.
really I never asked what he used, thanks.
Good videos 👍🏼👍🏼👍🏼👍🏼
Glad you like them!
Check for air leaks and impulse.
thanks
Ok, not always, but it sure feels like it sometimes. 🙂
this one is going to be a strange repair.
Run a pressure test on the cylinder
thanks
Change the spark plug put an NGK in instead of the Chinese one that's in it.
good possibility but stopping after less than a minute of running, and being able to start again, only to have it again, would make it a very special spark plug indeed
I came to hate Stihl over time, especially the cheaper ones. Such overcomplicated stupid machines. The non adjustable carb is nuts.
I know what you mean
Impulse line maybe
it's possible
I hate 2 cycle…
I would look further…
On those cheap kits I never trust the spark plug and have mixed results with fuel filters.
I hate 2 cycle
You also had someone else work on the machine could have messed up fuel line and filter during install.
I hate 2 cycle
thank you Pattay's Performance, it's always nice to see you in the comments.
That hipa plug isnt THE problem but it will be a problem
not sure why It was in there but must have been from the last guy that worked on it.
After that I would do a leekdown test
the following video shows what happened to it
Nothing to do with the carb it’s sommet in the tank not getting enough fuel the carbs working running fine just might be blocked in the air filter or fuel filter or lines I’d strip it all down start again new everything in
LOL.. you are very close to the answer!
@@HomeGaragechannel mention me in the next vid on this saw just so Ik how close I was
Keep digging. Try running it of a test fuel tank
thank you Russell Houghton and that's a great idea.
Second my guy!
That idle seems way too high. Probably an air leak.
yes it's hard to tell since the bar and chain is not on there.
The chainsaw might have an air leak
I'd send it to a mechanic.
nothing wrong with that, just the bill
Throw that Hipa trash out, I used their stuff as a brand ambassador, what a mistake
thanks
First
thank you Warrens Outdoors
Air leak.
If it is, then it would be the most interesting air leak I've seen.