I got the same exact saw a few years ago and I'm about to tear it apart now. Thanks for the video.

Just completed a complete fuel system cleaning and fuel line replacement on a 251. I can honestly say I have never seen what could and should be an extremely simple design become exceedingly complex and difficult to perform. It quickly became obvious Stihl design engineers and product managers completely despise repair technicians. For those that encounter a "sticky" soft start recoil pull, a tip. Remove the recoil starter cover and clean off all the dirt, oil, and debris from the starter rope assembly. No need to take the rope spool out of the cover or remove the rope, jusy spray it down with Simple Green or Purple Power and brush all the crap away, then rinse with a good stream of water from a garden hose. All that dirt and crud builds up over time on the pull starter and causes it to bind.

So you're not going to actually show the cleaning process, which holes, what product you used, how did you go about removing cleaning solution, etc. That's the whole point of this video beside disassembly and assembly. Need more direct to the point and skip the superfluous chatter.

The only video that even has a clue on putting the throttle linkage back on an MS251. Thank you!!! At $80 an hour i can't imagine ever letting a dealer work on my Stihls. Found a 9:56 on your video.

@A_Renaissance_Man

Жыл бұрын

Excellent. Thank you for pointing that out.

@mikeparker2865

Жыл бұрын

At $80+ an hour I’ll never have to worry about a shop ever touching any of my equipment.. I’ve been working on cars,trucks, farm tractors, etc since I was a teenager.. If I figured out how to do that I can figure out how to do the same on small engines…

Your video had convinced me to subscribe and say thanks for your help with the Stihl chainsaw. I do have the MS291 and it's kind of similar carburetor to the one you showed. The first issue as you mentioned was the damn 8 mm socket thin wall to fit in the holes and get to the nuts. After visiting few stores with the chainsaw with no luck, I just took out an old short 8 mm socket and polish it gently on the grinder wheel; it went in nicely. The rest of it with watching your video was easier, thanks to the great video quality..... I did not have the good spirit as you had since I wanted to get it done as soon as possible....It was tricky to return the needle valve assembly and finding T-5 key or some torx that fit. I found that screen you mentioned plug with dirt from the gas.. When I replaced the fuel filter in the tank I notice that the old one was cracked...... Bottom line, the machine fire up after many crossed fingers.....Thank you again...

Thank you so much! This helped me fix my saw today and I was able to clear out a fallen tree due to some late season snow.

Your video angles and showing all the parts and where they go, tips to remove and reinstall were all excellent!

@A_Renaissance_Man

Жыл бұрын

Thank you

Awesome! Thank you so much. I went the way of the slightly turned down sacrificial 8mm nut. Your vid saved me a lot of time.

Ignore the dumb critics about talking; it's how we all work. Good job. 8mm did it for my 261...thx.

did you try 1/4 in drive socket ? a 5/16 is exactly 8mm

There's a lot of great content here ... you just got to wait and wait and wait for it

@jjclarkson3261

Жыл бұрын

1.75 speed is about perfect

Thanks for the vid. Some useful info here. Now its time to get that carb of mine off!

I tighten / adjust my chain after each top off oil and gas. At least check it by pulling. Only time I’ve had issue with one nut was not checking it.

Had teh same problem with carburetor nuts: I figured out they are easily removed using a multiple tool screw driver. The one you can take the bits out of and flip. The 5/16 hex end works perfectly.

@A_Renaissance_Man

2 жыл бұрын

Thank you. That is great advise.

@mikeparker2865

Жыл бұрын

I just said screw it and took the bench grinder to a 1/4 inch drive 8mm socket I didn’t really care about 😂😂😂

@DescartesDooley

11 ай бұрын

I tried this, but the bolts were too long and not enough depth in the screw driver recess to reach. I spent the 20 bucks on the stihl tool. Easier than buying a cheap wrench and grinding down. I also don't have a grinder anymore

Thanks so much! I too was able to fix my saw that took a dive off the back of my truck. I didn’t know how the throttle was supposed to look.

@A_Renaissance_Man

Жыл бұрын

Your welcome. I am very glad this helped.

The diaphragm doesn’t pump the fuel. It meters the fuel. The opposite side of the carb is the pump, consisting of the pump membrane and two one-way valves.

The Project Farm channel has an amazing review on electric chainsaws.

Your video was the best I've seen, you explained how the metering device went in and the two holes for the adjusting screws, I almost put that in wrong. Great video!

@A_Renaissance_Man

Жыл бұрын

Thank you very much for taking the time to leave your nice comment

O yea the dreaded 8 mm. But all in all you did a great job I learned a lot. Thanks for your time and experience.

Thanks for the detail.

Following up on my comment about the special Stihl tool “STIHL 59108902420 8mm T-Handle Screwdriver”. I didn’t buy one in the end. It’s about Australian $30. Instead I bought a 8mm socket for $6 and then carefully ground it down with a zirconia flap disk on my angle grinder. Works perfectly.

Thanks for clarifying that a smaller 8mm socket will fit. I'm still struggling to take mine out.

@A_Renaissance_Man

2 жыл бұрын

Believe or not they actually make a 'special tool' for that. Fun Stuff. Good luck, it is not too bad when all is said and done.

@charlesmartinez5171

2 жыл бұрын

@@A_Renaissance_ManBelieve it or NOT! I'm still trying LOL

My 251C's carburetor, at least externally, looks just the same! (You mention somewhere that it's "completely different.")

You disassembled the metering assembly but didn’t check the metering lever height when you reassembled.

@A_Renaissance_Man

Жыл бұрын

You are correct.

I measured the ODs of my two 8mm sockets, the long one is 11.9 mm, the short one is 11.6 mm! The short one fits!

I have a 291, same carb, and it's a special tool, thin walled 8mm T handle socket. don't know why they did that! but I ordered it for about $8. fits perf.

@A_Renaissance_Man

3 жыл бұрын

Thank you for pointing that out.

@keithrayeski6417

Жыл бұрын

Just ordered mine!

You had me at, it's for your safety! Then you lost me at going electric.

@A_Renaissance_Man

8 ай бұрын

Turns out my electric endeavor is only good for small stuff and I still need the gas powered saw for tree trunks and logs.

If you switch to 1/4" drive socket you can then use metric or standard.

@A_Renaissance_Man

2 жыл бұрын

Excellent idea. Thank you

THANKS SHARING THIS VIDEO

Thanks for the video. My MS251 has become bane...as it is near impossible to start, and I've been looking for a good tear down video. Also, good to know about that second nut! I'll make sure to use a really thin walled socket to tackle this. I assume you're using a 3/8" ratchet; perhaps you'd have better luck with a 1/4" drive ratchet, or a nut driver...just a thought. Finally, I hear you about 'going electric'. However, until e-chainsaws get to where they can match the hp of the gas engine, I'm sticking with gas.

@A_Renaissance_Man

Жыл бұрын

Excellent. Electrical saws just are not powerful enough for trees. Smaller branches can be handled but trunks require the more powerful gas engines.

@JimDon-xj5qp

Жыл бұрын

@@A_Renaissance_Man Well, I've just torn down the carb on the MS251. And, for everyone else who may struggle with the 8mm nuts on the air cleaner, forget the socket; it turns out the 8mm nut driver is the perfect tool. It fit easily into the very tight cavity, and I was able to get on the nut with no problem. I tried several 8mm sockets, but not one would fit into the small space to get at the nut. Who designs these things, anyway....geesh.

Constructive criticism Use 1/4" drive with 8mm deep socket to fit in narrow access holes

@A_Renaissance_Man

2 жыл бұрын

Excellent. Thank you. I appreciate your input. Sometimes, I need all the help I can get.

@cbk-te7ru

2 жыл бұрын

@@A_Renaissance_Man no...... thank you.... Out of the half dozen videos that came up ..... yours was the most detailed that showed exactly what you were doing in your tear down. Helped me with my project immensely......👍👍

@ButterflyMatt

2 жыл бұрын

For the record, I have more than one 1/4” drive deep well 8mm sockets and none would go in the plastic access holes without having material removed from the outside. So I sacrificed/dedicated one too.

@dereksteele2284

2 жыл бұрын

It has to be thin wall

A 8 mm is .0025 bigger than 5/16 the outside socket is a commercial socket I’m sure Stihl has a special tool .

@A_Renaissance_Man

3 жыл бұрын

You are correct, I have been told that there is, in fact, a special tool involved.

Sooo glad you told me the size of those nuts at 8 mill. Very tight fit

I think the correct tool is called “STIHL 59108902420 8mm T-Handle Screwdriver”

@A_Renaissance_Man

Жыл бұрын

Thank you, I appreciate that info.

@nicklloyd9165

Жыл бұрын

THANK YOU

Fixed it.

Did you show the air and fuel path

@A_Renaissance_Man

Жыл бұрын

No I did not since the mixing point at the venturi was really the only obvious point of interest, I decided not to guess and be wrong about the liquid and air paths.

I appreciate the work you did for this video. Stihl should really use Allen head bolts instead of those 8mm socket heads.

When you started your saw the idle was so high the chain never stopped, so how could you say you fixed it? If it was idling normally, I would believe it.

@A_Renaissance_Man

Жыл бұрын

Two different things are going on. I fixed the carburetor and the fast idle is caused by the choke being on. The choke is turned off by the first pull and release of the trigger. Then the motor goes to idle. Sometimes I don't express my thoughts clearly. Thank you for pointing that out so I can correct that.

I’ve watched 7 and a half minutes of your video and finally learned how to get the plastic part off the carb. Now I’ve heard about two minutes of how you don’t have or weren’t using the right socket to remove it. The title of this video implies that you’re going to show us how to do something, but I have to quit watching because I feel held hostage by your talking and talking and talking. You also showed how to remove the choke linkage without even mentioning what it was or why. So you’re talking a lot, but not saying things that are useful.

@A_Renaissance_Man

2 жыл бұрын

I am not a technician. This was a learn as I go video.

@ButterflyMatt

2 жыл бұрын

@@A_Renaissance_Man I get it. I learn tons from regular people like you sharing their knowledge. I’m sorry to be a downer, but your content would be much more palatable if you didn’t go on repeating yourself about the minutiae. Unless you want fewer views and a one in six dislike stat.

Did it really start on first pull? Or did you cut out a few attempts? 😅

@A_Renaissance_Man

Жыл бұрын

1st attempt even to this day. No kidding, tricky editing, or cheating.

I cannot find a 8mm socket that'll fit in that deep hole. Found a crappy old socket and used a diamond flapper disk with the socket on a drill mowed the sidewalls down

@A_Renaissance_Man

3 жыл бұрын

I have been told that a special tool is used but I was able to use the 8mm by pressing on the socket and finally getting a bite on the nut.

Hi thx for that video! I just finished the same procedure...but cant succeed in getting fuel pumped. For some reason fuel is pressurized until the inlet of the carb but wont go further so that there is no fuel in the primer bulb. Cant figure out why, if someone have some idea to help :-)

@A_Renaissance_Man

3 ай бұрын

This was three years ago for me but, I do remember that the reassembly was very easy to get wrong. Each of the four gaskets had to be oriented correctly and the reassembly was orientated backwards from disassembly. In other words, I would suspect that one of the gaskets is orientated incorrectly and that is preventing the fuel from going to here it needs to go. Each gasket can be put in wrong by being up side down or 180 degrees out (Backwards). Good Luck and I hope this helped.

@3BTruck

3 ай бұрын

@@A_Renaissance_Man In fact, I just simply started the engine which ruuns quite fine but still fuel in the bulb, I will eventually guest whats happening later.

What other model diaphragm gasket can work???

@A_Renaissance_Man

2 жыл бұрын

Since I do not know if other carb gaskets are the same, you can buy a gasket material sheet at the auto parts store and make what you need. The gasket does not have to be perfect or look good. A pair of scissors and a razor knife should be all you need. Good Luck

@azardkhan2932

2 жыл бұрын

Actually it's a diaphragm gasket

Would this work for the 261c?

@A_Renaissance_Man

Жыл бұрын

I would think so as the larger engine is just a bigger piston.

@adambell3136

Жыл бұрын

@@A_Renaissance_Man I'm more worried about messing the computer chip up to be honest 😅😂

Those 2 nuts seem to be the hardest part

That linkage for the carb isn't as smooth as my 170 the 271 is kinda rough with that flip up design maybe it's just me thou

Muchas Grasias por este video porque yo tengo esta motosierra 251 y quiero cambiar el carburator

Any problems with stihl 251 ?

@A_Renaissance_Man

3 жыл бұрын

No problems. Had to clean the carb, but that is a fuel gumming issue and has nothing to do with the saw itself.

@juniorboyd6974

2 жыл бұрын

When storing it empty out all the fuel and run saw until it dies.

I would have preferred seeing it started from a cold start. After all. Wasn’t that the original problem?

@A_Renaissance_Man

2 жыл бұрын

It started right up. Maybe I filmed the second start. I'll have to watch this again. I definately don't cheat in my videos.

1/4 ratchet better for those 8mm nuts.

@A_Renaissance_Man

Жыл бұрын

You are correct and I dont know why I used 3/8ths.

I'm here because I'm having the same trouble trying to figure out what size those nuts were as well!😠

The nuts were hard to get off because you use the wrong tool. try the 5/16 driver screwdriver. take the flathead bit out and slap it on. EASY.

You didn't even mention the high and low speed mixture adjusting screws.

@A_Renaissance_Man

2 жыл бұрын

You are correct. As a matter of fact I have never had to touch them on any Stihl product I have owned.

Great -- so completely skipped Primer Bulb removal/installation unless 251 doesn't have one. 251C does however.

@A_Renaissance_Man

3 жыл бұрын

Thank you for your comment. There is no primer bulb on this model. I do have a how to start video on this model which demonstrates how this starts without one.

@jimdever4346

3 жыл бұрын

@@A_Renaissance_Man Good, but I have a 251C

@chrifaranaudo123

2 жыл бұрын

So find a different video

@kcpiggott10

2 жыл бұрын

@@jimdever4346 good for you!

Was looking into buying one of these saws, but seeing your video has told me to go back to the ms250. These pieces of junk are made as cheap as the company could make them and sell them for to much money. They just won't build a quality home owner saw. Even went as far to only use one lug nut on the chain tensioner. And take a look at all the plastic in the carburetor and throttle assembly.

@A_Renaissance_Man

2 жыл бұрын

I agree with you on that point. They are make for maximum profit not maximum quality.

@aportilla007

2 жыл бұрын

I'm dealing with the same saw, same bullshit - after cutting down just 3 trees - 1/2 day work. It is built cheap. I would have never bought it if I'd known.

Why are you taking the carburetor off was it not running I assume. I have this saw and never have a problem. Run clear gas only!! They have problems staying tuned. You need to know how to adjust the carb correctly or you will make it run worse.

You're extra bud

Don't be stupid, you'll change back . Evidently you only use one probably every 2 or 3 years. Backyard cleaning. Electric runs about 30 minutes and quite, then recharge time you probably work hard need a 1 hour rest anyway.

@A_Renaissance_Man

2 жыл бұрын

I had realized that electric is the way to go for me. At the time of this video, electric was unavailable.

If you use the craftsman 1/4 inch drive and 8mm socket you could eliminate 10 minutes of dialogue and grumbling. You did not address cleaning of the high and low speed adjustment screws.

You know it's a German saw right...of course it's 8mm.

@A_Renaissance_Man

Жыл бұрын

You are correct.

@PeterBaumgart1a

Жыл бұрын

What is 25.4 times 5 and divided by 16? (The difference to 8 is within most screwhead's tolerance.)

German design, almost always is going to be metric bolts and screws.

Talk way too much. 35 min should have been 10. Informative, but too much talking about useless stuff.

@marinamile

3 жыл бұрын

Lets see you do better!!!

You skipped half the steps

Electric sucks. The batteries are expensive, they only last so many charges, you need tons of them to work all day, they dont work good in the cold, or the heat, and they are hazardous waste.

@A_Renaissance_Man

5 ай бұрын

Well, the truth, the whole truth, and nothing but the truth.

BWXT lol

@A_Renaissance_Man

Жыл бұрын

Did I say that? Hopefully I did not devoluge any Confidential information, 😆

Why not drill the plastic so that your socket fits in it? I used an 8mm long socket and it fit fine. They must do this on purpose, so you'll get frustrated and take it to a repair shop.