Stihl 025 chainsaw no start diagnostics

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[@chrisbuccitelli9023]

I have one from 1991 and it is still running strong. 93 octane fuel, and startron fuel additive

[@downloadedxzx]

I was running this saw for about 2 hours at about a 30-50% duty cycle kzbin.infoUgkxfQm1wmg0ItKDLavxj1nXtQY9HP7EF504 and it did a great job. I used the lever for the built in sharpener to clear chip buildup out more than to actually sharpen the chain. It managed to cut some hardwood stumps much larger than it's size without bothering the neighbors with hours of 2 stroke noise.

[@keithbess516]

Well it looks like you deduced it was not getting fuel, but that does not conclude it is the carburetor. Maybe there if a fuel line or filter problem

[@paradisebird7108]

Indeed, without the filter with new carb the plug doesnt get wet :(

[@irishsailordog1391]

GOOD YT a simple procedure to eliminate the three main problems, NO: Fuel, Spark or Compression. Here's a couple tricks to add to your above average YT. 1 - boot too big to hold chainsaw using foot rest = take any piece of board or steel that fits thru the slot between trigger assembly and foot rest then you can place your boot on the board and it will hold down the saw if needed and the board long enough you can put a boot on both sides. 2 - a fair amount of times you need to use full throttle which can but not always be hard to do requiring more then two hands etc. Remove air filter or what else needed to access compartment holding carb look inside and pull throttle back and forth to see the mechanisms that control the accelerator, a lot of times you can insert a block or other solution to interfere with the return of accelerator connecting rod so it can't return - attach or staple a piece of string to the block to force the the full throttle position to not return to low that way you can instantly pull the block out quickly after it starts. NEVER run a cold saw if started on full throttle at full throttle until well AFTER the whole saw has had a chance to warm up at low throttle; doing this can often cause piston damage or seizure and render your saw into history. Good job on your YT.

[@colerobinson8527]

Carb is not always the problem on these older saws I’ve replaced a lot of impulse lines and that was the problem

[@7400Denmark]

I would like to see it start twice ? Good job !

[@TraumaChaplain]

Since it's getting near hurricane season can you demonstrate how to start a generator perfectly every time assuming it has a clean carburetor and good gas...

[@larryseago730]

What Keith said below. But, buying the carb kits on ebay, all that stuff comes with the kit, so you just change everything out, and get new fuel lines and filters, etc.

[@paradisebird7108]

Mine the sparkplug doesnt get wet, cleaned the carb, used a new one, still dont start without putting direct fuel.

[@edwardfowle2404]

I have a 034 stihl that won't start and I used the old fashion putting a cut plug wire and stuck one end in plug cap( did strip wire) and took it about 1/4 inch from frame. no spark. how else can I verify its not getting spark? Thank You!

[@RCASSIN]

I have good spark. Ii poured starter flid/gas down the plug hole but still no start. Any recommendations? thanks, Rob

[@greggschultz5768]

There is no half choke. The switch setting you are talking about is the high idle setting. Check the manual to confirm this.

[@RG-wy1ol]

Thanks for making this video very helpful and educational 👍🏽👍🏽

[@chuckreed2677]

Can you tell me how much fuel you put in the cylinder, 4 or 5 drops?

[@toddkratzer7953]

Why didn't you check for spark first thing? Instead of removing spark plug to check for scoring then putting it back in to check for spark then taking it back out to dump fuel into it.

[@jasonblanton7185]

You shouldn't just assume it's the carb ,it could be the fuelline or the filter ,easy to check as well.

[@avalanchereviews2352]

That is correct. Maybe I should have checked that. However, more often than not it ends up being the carb. Plus, I always change the fuel filter every time I change a carb. Thank you for the feedback, I will be sure not to leave out info like that on future videos.

[@timboltz7421]

sthil o25 o28 sthil chain saws how much you charge to fixs ther carbs

[@larryreno8293]

The pulse line could have failed, fuel line split, filter plugged.... the only thing you know is that you have a fuel delivery concern. You should continue with your diagnosis and not jump to conclusions, you owe at least that to your customer.

[@oring137]

This was helpful in diagnosing an issue with my 025 Stihl..It would be interesting to see how one is broken down to verify the piston scoring mentioned

[@neilhamill318]

To get a true indication of piston scoring without having to dismantle the engine is to remove the exhaust on look directly at the piston. Pull the start cord slowly to view all the piston and the barrel were scoring can occur.

[@roniler7960]

What if it starts & idles,But once you squeeze trigger it stalls out?

[@TheKrayusKorianis]

The H mixture screw needs to be turned counter-clockwise to increase fuel. It should just be a small turn.

[@tarnicasper4632]

So please let me know, could this not be fuel feeder tube problem?

[@ralphcrabtree5687]

I have an 025 that will start and run for 5 minutes and idle for 30 seconds and then cuts off and will not start. Any ideas whats wrong

[@SksToTheMini14]

Same problem here

[@my83roadster4me]

I wouldn't be certain it needs a carb from that diagnosis.

[@tudor41746]

I agree

[@bobwoerner8731]

have an 024 ,,,was running fine 4 months back. but tried a week or so ago . would kick over with a blast of starting fluid then just die .over and over.emptied tank and checked fuel line which just fell apart when i grabbed it.took it to a stihl dealer to have new fuel line installed .told him to use the same filter,,,,,,,,,they called today and said they changed the fuel line for 28.00 bucks but the saw wont even kick over on initial pull..asked if they tried it with starting fluid but they said they didnt have any ?,,,,,,,,,,guess ill pick it up and try to figure it out,,,,,,,any thoughts?.

[@avalanchereviews2352]

sounds to me like the carburetor may be plugged up, and either needs to be cleaned or replaced. the rebuild kit a K20-WAT, and the new carburetor Stihl part number is 1121 120 0611. It is always a good idea to empty the tank and run the unit until it dies when storing for an extended period of time. mixed gas tends to go bad and start to gel up after a while of sitting. I hope this helps, and if you have any other questions, Please feel free to ask.

[@felipesandoval7593]

Hey buddy I just bought this 025 USED GUY SAID IT STARTED FAST WENT AND GOT IT.HAS SPARK BUT WONT START

[@stefanodogg280]

The carb is probably just clogged and needs a good soak in Seafoam mix. Run your tools dry every fall with a little Seafoam in the mix and you will be OK

[@cristinafultz4572]

What about the fuel line

[@mooregoodink7734]

After cleaning the carburetor, my MS250 Stihl ran well but over a two-week period it began to smell rich particularly when idling. Then it refused to start. I leaned the idle air-fuel mixture by one-eighth of a turn but nothing would induce it to start. In thought and deed, a day's time vanished: checking air filter, fuel filter, compression, the spark--in fact, the spark plug was removed probably five or eight times. Each time its condition was visibly wet and each time I dried it. The Stihl manual states the plug gap as 0.020in. Mine was probably 0.025in or greater. So I reduced the gap, installed the spark plug, and began pulling the starting cord, avoiding choke and half-choke positions but still to no avail. I fitted a pair of slim shoes and slipped my right foot through the handle far enough to engage the throttle trigger. After a further 10 pulls or so, I noticed it seemed to fire--almost imperceptibly. Then, the firing became more audible and shortly after it burst into life. My conclusion was that it was rich, soaking in fuel.

[@DavidGurrney7589]

So what did you do to correct it because mine has the same problem. I am leaning towards carb.

[@mooregoodink6971]

@@DavidGurrney7589 Hello Vinny, it's a year ago but from memory this chainsaw had one major fault; that is, when at normal operating temperature it idled for about 15 seconds and then the engine stopped. The secondary problem I wrote about above was caused by my own stupidity: I applied full choke to restart it and flooded the thing. But the primary problem (quitting during warm idling) was likely cured by an 1/8 to 1/4 turn on the idle mixture screw. My comments above indicate richness and, if so, the idle screw required a small turn inward to reduce fuel flow. However, it is much more common to increase the idle fuel by a small amount to encourage the saw to idle when warm. Cheers Vinny and hoping this helps, Vic

[@mooregoodink6971]

@@DavidGurrney7589 Hello Vinny, after I wrote to you I wondered if your Stihl starting troubles were the same as mine (won't start when warm) or won't start at all. If it is the latter, turn the saw on its side, open the throttle fully and pour half a capful of fuel mix into the crankcase. Apply the choke and pull the starter cord. This technique usually causes the two-stroke machine to fire and run for a few seconds. If so, you've proved the saw has sufficient spark and compression to start and the trouble most likely lies in the carburetor.

[@buster2725]

Hi my stihl 170 has 3 new plugs new carb no high and low needles to adjust. new gas filter and air filter and gas line muffler clean great spark the idle screw 2 turns out like the book says,and new gas mix in a can from stihl and it still won't start,lets hear some fancy answers

[@TheKrayusKorianis]

Does it have a new impulse line?

[@pthrelkeld090]

I'd go ahead and replace the fuel filter/ line assembly INSIDE the gas tank before you go tearin out the carb? Otherwise you may be inadvertently overcharging people due to misdiagnosis

[@tomkrzemecki5166]

I have an 025 like this. Can you show more detail on the carburetor linkage?

[@joejones4820]

Thanks for the info. Good instructional video, Sir.

[@Hollywoodhouse74]

The gas was checking in but not checking out... lol

[@johnkosheluk1041]

Ok what about a psi test or vac you could have a air leak or impulse line off

[@joaniebarton3472]

Stihl fs120has Lowe spark can you help thanks steve from uk

[@Hollywoodhouse74]

Check the exhaust screen.. that's what was wrong with mine

[@louleone1032]

Good Video, Buy a stand for your camera...

[@johnclarke6647]

Your first comments should have told you what was wrong - stinky fuel. The first thing I would check is for spark. Compression should be evident by pulling the starter rope. Old fuel means gummy carb. The next thing I would do is pull the carb. Gas in the cylinder does not work as well as gas down the carb because two cycles put the gas and air mix in the crankcase, first, and then in the cylinder. On the 025 the choke spring in the air filter can be a real problem because it can stay on and make the saw impossible to start. My guess is a filthy carb. And bad diaphragms. .

[@rickybigriggun8971]

I need to know how to change a spark plug on a 024 av still chain saw

[@rfshields1]

RickyBigRig Gun remove top eld in place by one slotted screw. Pull off rubber cap from spark plug. Remove with your saw’s wrench.

[@danielenfinger3927]

Huge help Thanks for sharing.

[@calebwillhelm2635]

Why does my ms250 have 165 psi

[@jeffmays3608]

165 is good. 125 like he mention in video not so great, not terrible but definitely some wear.

[@chrisbuccitelli9023]

It was not the carborator , it's your fuel . Or the fuel filter. Big box store fuel is junk

[@juliamarple3058]

You’ve got the choke on, or chain break off. It looks new

[@kenhardy4167]

Good, but incomplete diagnostic evaluation: Repair technician should first thoroughly check fuel filter, fuel line, and fuel lIne connection to carb before deciding that a new carb is needed. If those three are all fine, then old carb should be removed and either a gasket kit installed in it (time-intensive and sometimes inadequate with some internal carb hardware problems), or install a replacement carb (OEM-very expensive; Chinese clone very cheap, but less reliable). Knee-jerk replacement of a carburetor will not repair an air-leaky or disconnected fuel line, nor a clogged fuel filter…..both are very common problems that are simple and cheap to fix. Also please note that too much gas added directly via the spark plug opening will flood the engine and no fire will occur even in the face of repeated cranking. If this occurs, always check spark plug for wetness/flooding, de-flood and then repeat with smaller amount of gas mix directly added. I prefer to first remove the carburetor entirely, pull the piston into TDC, and then add 1-2cc of fuel mix through the carb intake boot directly beneath the piston into the crankcase…..this is much less likely to flood the engine, and repeated cranking will eventually unflood the engine anyway, allowing it to fire up briefly if vacuum, compressionmand spark are all OK. Dealer repair shops rarely take the time to do this, instead they just tell you that your engine/saw is toast and that you need to buy a new one…..good for their business, bad for your wallet. Dr. K.

[@DougHinVA]

damaged fuel lines or filter is a good start and obvious. Dump any old fuel and evaluate it. piston view .... 'you can't really see in there but it looks good' with a flashlight.... what ? no solution or action.... skip it

[@adrianb9081]

Ikr it could be gas line fuel filter or impulse hose

[@jacklavel]

Sthil ms 024 is similar to a model ms 230 sthil. Sounds already the same..

[@exinanition2307]

The video clearly shows the fuel line coming up out of the carburetor and it is cut off. The fuel line is not even connected to the carburetor. There is a very clear shot of this at 3:32 in your video. Also, when you do a compression test the throttle needs to be wide open. I do not mean to be condescending or rude but you need to be a bit more thorough in your diagnosing a problem with an engine especially if you are going to making how-to videos. I wish you all the best, sir.

[@avalanchereviews2352]

That "fuel" line that you see there is not a fuel line. What it actually is, is a fuel tank vent tube. Thank you for your observation though.

[@avalanchereviews2352]

Stihl does not use thygon fuel lines on their saws. They use custom fit fuel lines.

[@avalanchereviews2352]

And if the compression is good at no throttle or half throttle, it will also be good at full throttle

[@avalanchereviews2352]

Not to be rude, but you should get your facts straight before making comments like that. Best of luck to you as well sir.

[@giantsdude1017ify]

Oh,Hi!!!!!!!

[@chrpchr1christodoulou476]

The fuel line has a problem,

[@avalanchereviews2352]

The fuel line that you see there is not actually a fuel line. It is actually a fuel tank vent tube. Stihl does not use tygon fuel line line on their saws. They use an OEM molded fit hose.

[@Pr0ph3cy-k5z]

Sadly, you done the grunt work by diagnosing the issue and probably don't get much $$ for diagnosing. The customer can easily change the carb him/herself. I'd give options. Here is my diagnostics fee if I don't get the job. No diagnostics fee if you hire me to do the job. I do diagnostics on automobiles, computers, small engines, appliances etc and will waive my fees if I get the job. If I don't get the job, then I hit them with a high diagnostics fee.

[@avalanchereviews2352]

JackOfAllTrades I do the same thing. 1/2 hour minimum diagnostics fee. Unless i do the job. Then it is normal labor rate only.

[@Pr0ph3cy-k5z]

How To Great. I know a lot of people diagnose for free regardless if they get hired and most of the time, the customer will either do the work themselves or get someone else.

[@jr4750jr]

Can't really see in there but looks good????????? WTF

[@avalanchereviews2352]

jr4750jr sorry, but i meant that you can't really see down there with the camera.

[@avalanchereviews2352]

@David Jones, Thank you for the feedback about my speaking more clearly. Plus... that isn't always true. with a scored piston and/or cylinder, you could have compression cold, and lose compression when the unit gets hot. I have seen it hundreds of times.

[@avalanchereviews2352]

Yeah, them older saws are harder to work on and harder to find parts for, but when you do get it going, they run great, and for a long time.

[@JuiceBanger1]

@@avalanchereviews2352 interesting. Never knew that. Thanks.

[@iridefast1]

👍

[@michaelmarton5483]

Impulse line

[@kevinalbers1084]

Get a tri pod

[@jeffbang7847]

Need to replace more than the Carb! Replace the Chainsaw with a Quality Chain Saw! My New Stihl Never ran and had to return it. What a battle that Was!!! Buyer Beware!!!

[@peytoncare3181]

OPERATER ERR

[@jeffbang7847]

@@peytoncare3181 Fixed it by returning it and purchasing a better Brand that actually works!!! :)

[@deecee2837]

Bang! KaPow!

[@poorsalotto6108]

Lol