Stihl MS291 Chainsaw! HARD To Start! Bogs Down! No Power! Any Guesses? Let's Dive In Together!
2024 ж. 25 Мам.
49 600 Рет қаралды
This STIHL MS291 Farm Boss Chainsaw was dropped off for repair! It is hard to start and BOGGY! Let's dive into one of Stihl's most popular chainsaws and see what the problem is? Can you take a guess as to what is wrong? Come along with me and let's find out what is making this saw misbehave!
Thank you so much for joining me!
If you enjoy watching me navigate my way through a chainsaw - be sure to check out my other chainsaw vids!
Thank you watching! Please Subscribe! I will keep the camera turned on!
I am a small engine mechanic for many years. Wow I watched a few of your videos and a cannot believe how calm and well spoken you are. You remind me of my elementary school teachers back in the 80's. I really appreciate you taking the time to make these very well made and educational videos. I have not found one error on the way you work or tips you give to your viewer. Fantastic job! If there is one thing I can suggest to better your videos: You should do something about your mic because when you unscrew bar nuts and the saw bounces on your wood workbench or when you turn the saw around, you sometimes hit your mic and it sounds like an explosion in the audio. You should get a mic boom so you don't have to wear it all the time and put a mat on your table. ps: Always try to start the saw and replicate the problem if you can before you even do anything to it or the fuel. The carbon buildup could be due to using a low quality 2T oil or a 2T oil the wrong flashpoint temp. Does he own a boat? Ask him if he's using marine 2T oil in it. LoOl.
She is great mechanic and teacher 😊❤
1¹¹
@@philliphall5198 I wonder how she learned? Family member business?
She took the fuel out to inspect it, but then put it back in to replicate the problem.
Nice job walking through all the diagnostics. I like that you save the old parts and can explain why they need replacement. You actually do the work to arrive at a conclusion, not just firing the parts cannon. Well done!
Clogged spark arrestor?
@@jasonmercer9962 Huh? What about it??
I've been a mechanic for over 50 years. Many of that small engine. You are a very good tech. I appreciate your methods.
Yes! She's waaaybetter and more torrough than famous Chickanic. In case of Chickanic she skips half of the tests for example I've never seen Chickanic doing the pressure/vacuum test..
I don’t think we should be comparing technicians. Bre aka Chickanic has addressed some common issues faced by homeowners whereas I have not seen other techs address simple solutions.
I agree about comparing techs. Let’s be kind and thoughtful.👍
A pleasant demeanour and an expert touch, The show reminds me never to touch a carburetor, ever.
If only the OEM Mikuni carbs on my old Yamaha ATVs were that simple to rebuild!
One thing that I have found as a Stihl Technician, is that you need to make sure the cylinder has some fuel mixture in it. Just a small squirt will not flood it but lubricate it and prime it to start easier. Always hold the interlock and the throttle wide open and set to full choke if you are not prep-priming the cylinder under normal circumstances. you will notice that even though the choke is fully closed, the throttle is open somewhat. This reduces pulling tension needed to turn the engine over faster and with less difficulty. 1 to 3 pulls is all you need normally with full choke. If the saw "pops" then immediately, without touching the throttle, move the choke lever to half choke. If you have per-primed with a small shot of fuel into the cylinder for lubrication this is where the choke needs to be in this sequence. Now the throttle is still open but not fully choked. This makes it even easier to pull with both butterflies open. The saw will usually start very quickly with just a few more pulls. The engine RPM will race so be quick to pull the throttle to fully release the choke and lower the RPM as needed. As we work on these saws we learn the interlocks both at the throttle and in the linkages to help us start these powerful tools.
Just discovered your channel, you are very good at no nonsense explaining the things that 90 percent of home owner saw users do not know. Best wishes
Hello! I'm a Swedish guy who loves stihl chainsaws more than anything else but I have to praise you for your professionalism and knowledge in what you do and I love your videos😍so I'm looking forward to new videos there you fix your customers' chainsaws🙏 Mvh//Morgan from 🇸🇪
Carbon, oil residue below a good set of rings can come from a to rich mix. With the air filter as clogged as that one is it was starving for air and that made even a proper mix to rich. The engine running this rich will not get up to temp that would normally vaporize the oil in the crankcase and consume it. So it coats everything and it never tends to relieve it cause it can’t, it’s not hot enough! Short run times also does this especially in winter!
It will also coat the muffler and spark arrester. sometimes clogging it up so badly that the engine will idle but won't run at higher RPMs. In this case remove the spark arrester and with a torch flame burn off the carbon build up on the screen until you can see through it. Older two stroke mopeds used to clog up the muffler and run poorly. by taking an acetylene torch and starting the build up on fire you could then turn off the acetylene and leave the oxygen on to slowly burn out the carbon build up. usually the outside of the muffler would glow red where it was burning, so, if it was too red it would burn a hole through on you. Adjusting the oxygen for a good slow burn usually worked the fire through the whole exhaust.
It's very common for Stihl Ultra to carbon up the piston like that, especially the side of the piston. Have the customer run Echo Red Armor, it takes a while but the red armor will clean most (not all) of that carbon off. Nice video, you're teaching well.
Thank you. I’m thoroughly addicted to your videos, and I’ve learned a ton! This one especially because I have an MS291!
Glad you like them!
A nice trick for keeping the spring from falling over while installing it is to put a drop of oil in the spring pocket. The surface tension of the oil works surprisingly well to hold that spring in place while reattaching the metering lever and arm. Thank you for sharing once again great and informative videos.
Excellent info.....even sweeter knowing you're Canadian. Keep up the good work.❤
I don't like to bad-mouth someone behind their back, but it sure looks like this owner doesn't know the first thing about chainsaws. (Though they apparently did at least know about adding oil to the gas.) Part of your repair package should be a copy of the owner's manual. Love your videos! They're super clear and educational.
HEY! Thats my saw. Just kidding.
@@user-dj9us8ic7m I'll bet my dad might have owned that saw at one time. He didn't like getting his hands dirty or doing any maintenance. Of course, when he began having problems, he'd complain that gasoline engines were a curse.
Good job on the tuning immediate throttle response.That was a quick hour long vid.
Excellent video. A real masterclass in diagnostics and methodology. Great work. Paul. London, England
A trick I learnt is to put the metering screw in loosely then drop the needle in hook the metering balance under the needle. Then pop the spring in. Then you can slide the pin in from the side and tighten the screw
I’ve seen those deposits on the piston from the use of old fuel and/or poor oil quality. Great videos by the way. Clearly and logically presented and easy to follow. Cheers from Australia.
These are some of the most thorough explanations and tutorials that I have seen on KZhead when it comes to small engine repairs but they are long. This video speaks to keeping your equipment clean with good fuel. Thanks!!
Stihl ultra. Carbon buildup after 1 tank! I can only imagine after 50!
Right!
Excellent start to finish with only a small omission of the needle valve settings, and adjustment of idle and high speed screws using a tachometer. I would have liked that to be included, but otherwise, I think you have the absolute best videos helpful to viewers. Thank you so much.
Well done. Thanks. I learned a lot.
That Saw probably never ran so good before you touched it! Fantastic video!! Very detailed. I loved every minute of it. I only get to use my chain saws once or twice a year if im lucky and have learned a bunch from ya!!
Thanks 👍
Thank you my Chain Saw repair Friend 😊 I own a MS-291 😊 I can know keep my EYES on the most important part of preventive maintenance, for running my baby.
Glad to help!
You can put rope into the spark plug hole if you don’t have the tool to stop the piston. When setting the coil, you can put a business card between the flywheel magnet and the coil if you don’t have a tool, and the magnet will hold it at the right position for tightening. I worked at a tool rental store and we had about 7 Stihl saws. They were great runners, but all of them were hard to start cold.
I am a fairly new subscriber and a small engine mechanic in central Ohio. I want thank you for your in depth videos. You explain everything thoroughly and show what you are doing. I have a bore scope on my wish list. They really help in figuring out what has happened to the equipment. I also watch Brea the Chickanic on her KZhead channel using her scope. She also lists the tools she uses in the video description which lets others know what she uses and occasionally will do a tool tutorial to answer those questions before they're asked. She is an Echo dealer in Arkansas. Thanks again for all you do. Ray from Central Ohio.
Wonderful video. Thank you for being so thorough with your diagnosis and repair.
I really enjoyed digging into the MS291! What surprised me the most is the owner/operator! The MS291 is a beautiful saw and is expensive to replace. I was shocked at how poorly this saw was maintained and the lack of bar oil nearly knocked me off my stool! The fine dust you uncovered in every nook and cranny tells me this saw was operated in this condition for some time and not just one tank of fuel. Superb video once again! Thank you!
You do a great job of explaining what to do and what you are doing.
When I was logging in the 1980s and early 90s my go to saw was my Stihl 084. Favourite saw ever. I did buy a brand new 090 just for one job with a 6ft bar lol. That thing ate that massive log. Good ole old growth trees
I wish I had such a dedicated and competent technician near me. Great information video!
One of if not the best videos I’ve seen on diagnostic procedures! Thanks for all the work you put into this.
Not only are you a master mechanic but more importantly you are a master teacher brava!!
after the rebuild,helps to adjust thr idle and high speed jets. Screw in until closed, then set as required by stihl. Just takes a minuteand removes any tiny debris and makes certain that someone has not made a wrong set. graet video!
Thank you so much for your instructional videos - they have been a tremendous help to me! I'm a Stihl Tech (several years) and can honestly say that you have taught me so much from just this one video. I feel like I've found a jewel - thank you and keep up the great work!
Wow, that makes me happy!
Great videos, very well done please keep them coming. I have learned many good repair techniques from your channel.
Your videos are always good and get better all the time. Thank you for explaining the impulse driven fuel pump and for getting the Depstech bore scope! 😊👍👍👍
Excellent job explaining the why and wherefore. I have always used ethanol free gas but I never knew why. I would love to have heard what you said to the owner. There should be a Society for the Prevention of Cruelty to Chainsaws
Excellent video. I like your attention to detail and systematic approach to repair instruction. I have worked with the Scouting program for some years. My #1 safety tip is to always look to your non-dominant hand before taking action. Normally your dominate hand will be the focus of your attention and the one holding the tool. Whether it is a drill, hammer or chainsaw the hand at risk is your non-dominant one. A friend lost most of his hand in a chainsaw accident by ignoring this rule. Keep up the good work. There is too much garbage and not enough good instruction on the internet these days.
REALLY appreciate your knowledge and ability to teach! THANKS
Great video,camera ,glass jar,you explained fuel with dirt and water.also how important bar oil is.the tips on a dull chain are spot on the money.I don't think i could ever cut wood again without a sharp chain,I've also been guilty of letting my chain hit the dirt.Sometimes i even did it ON PURPOSE .to get roots.haha good going.
Stoke the fire then get the coffee pot going 😊
Your instruction is very easy to understand. I will be using your videos to guide me when working on my saws. Thank you!
Hi and Gday from sunny Queensland , Australia , top vid this one , thank you , cheers
I was definitely thinking carb rebuild when you first checked it out. When I saw the air filter, I was aghast at its condition and second guessing myself. That is, until I saw the diaphragm. But that carbon on the piston - oooh doggy! I don’t think I have ever seen that even on the old crap I work on!
The one thing a lot of people dont talk about when it comes to diagnosing diaphragm type carburetors are the importance of its internal check valves ,a fresh properly instaled rebuild kit will not fix a Carb with a bad check valve , there is usuly one in the main emulsion tube , and one in the idle circut. these tiny check valves are also why one has to be careful with what carb cleaning chemicals are used in the cleaning process, as some of them will turn the tiny flapper inside the check valve into a glob of goo ruining it ,, check valves can fail closed and not pass fuel either direction, (most common) or fail and allow it to flow both directions when it should not , either failure will cause runabilty issues due to this hidden fault .. can you refect on that in the future ? many shops wont service a carb with a bad check valve due to labor required to press it out and change it , and some carbs do not have servicable check valves anyway, its just something to bring awareness too. .
You’re absolutely bang on! I am going to talk about check valves in an upcoming video. Thank you so much for your comment!
Saw repair is my favorite!!!!!!!!!!!!!!!!!!! More!!!!!!!!!!!!!!!!!
Lots more coming up! I had 6 more saws get dropped off today!
You MAM do an exceptional job at demonstrating multiple diagnstics.. Ive been a small engine tec for years and still I watch a lot of youtube videos. Your by far the best instructer ive watched on line...thank you for what you seem passionate about,such as instructing procedures. Keep up the great videos.
Thank you!
I recently watched a video about how clean different fuels burn,most of the premixed fuels suc they leave tons of: residue
Well done 🙂
What a fantastic channel, how I hadn’t found it til now is a mystery! VERY nice job diagnosing these saws and providing useful information to the average person. I am a “Stihl afficianado” myself and love to see all models come back to life when possible. Excellent presentation, watching is very easy as it all flows nicely. New sub from Wisconsin!
I’ve been servicing small engines for years but I still learned from you. Thanks.
Great job. Very clear and focused video. Thanks!
Love the thorough overview during the troubleshoot,great job.
Thanks for sharing your valuable time and resources to present this well presented chain saw repair. May all your days start with sunshine and end with a smile.👍
Excellent methodical troubleshooting!!! Have you thought about writing down the checklist steps and posting them? That would be very helpful to keep on my workbench. Thanks for your vids!!!
HUGE amount of Blowby on piston, worn cylinder or rings. must be low compression? GAS/OIL blows past rings and runs super rich. great videos by the way!! always learn something
Great video I am glad that that you don't have to work on mine chainsaw I have a good clean and work place habit that was a mess of a chainsaw wow but u always get it running and clean up a great job and video be safe and enjoy your free time from the saws
Great helpful video. One extra thing I learned the hard way on my 20 year old saw was that I needed to remove the pull winder periodically to clean out dust/chips. They were collecting around the ignition coil and it needed replacement due to heat buildup.
Luv the bore scope!
Another excellent video. It's amazing how some people don't add bar oil. I swear by Amsoil 2-cycle oil in my chainsaw. No issues at all. John from MI
I learn so much! Thank you!
Great video, thanks for sharing.
Excellent Job Great Detailed Video I Like The New Bore Scope 😀👍🏼
Excellent diagnosing skills and awesome fix ! Just perfect 👌
As informative and detailed is your explanations are, don't worry about the length of the video. Would like to see more in depth explanation on carb air fuel mixtures . Old school tip, Chuck a q-tip in a drill and use it to polish the seat . Long story on how I found out this works. Thank you again for the great content.
good job done
I really appreciate the process and detail that you provide in analysis and subsequent resolution... nicely done.
The piston looks almost like it has been run on a lot of stale fuel. Ther is a picture of it on the echo piston failure chart. I have one of the older 290's its still a great saw.
Glad I found your channel, very informative. I have two old Stihl 031 saws that I cut wood to sell. They both have some problems but I manage to keep cuttin firewood.
Excellent job thank you so much!
Absolute top class video & commentary. Tuning the carbs to Stihl specs : would like to see that process.
Meant to add : regarding the video recording, I found sound quality good, and the lack of background music is a major Plus ! All the better to hear the explanations. Your purchase & use of the endoscope camera is a major boon. Never saw pressure/vacuum test on a crankcase before and I think I'll rob that idea to rebuild my old Suzuki V-Twin two-stroke motorcycle.....and maybe a Vespa or two... 😀
Brilliant content and presentation. Great tutorial.
Excellent video. Very clear and complete. Often how to videos rush through the details or maybe what they consider to be mundane processes skipping over things I need to know.
Thanks for this informative and educational episode.
Your customers should greatly appreciate you! I appreciate you and I just found you on you tube. Thanks!
I own an MS291 and learned alot from this video. Nice job. Thank you.
I'm glad you started using a clear glass jar to assess gas. It's easier for us to see. :-) Thanks for all you do for the rest of us!
Yes! I hear everyone's requests and I am trying to make it better. I have pipettes, glass jars and a borescope now!
Thanks for doing that for us.
I also like the closeup view of the carb. Thanks for that!
Great video. thanks for your work.
Much appreciate your videos. Very clear. Very precise. Presently running three saws. 2 50cc farm boss and one 75cc with a long chain bar. Nice to be reminded of why taking care of your machines is important. Like the new camera.
Good job😊
Thanks for making these videos. Your diagnosis process and explanations make these video's great. Your explanation rebuilding the carb in this video helped me alot. I was able to redo my carb this weekend. Thanks.
Amazing!
Thank you very much for your video of the show how folks miss use a chain saw. Plus, go, girl, great show, thank you. Thank you for many hints, too. 🤗😊👍
Really enjoyed watching that video as I have an almost still new MS291. It has a ton of compression. But it usually starts right up on either 1st or 2nd pull after choke. You do a great job of diagnosing the problems with chainsaws brought to you. I am very impressed.
Try pushing down when backing off bar nuts, much easier than trying to hold the saw down and pulling up on the wrench.
i suspect stihl/ castrol oil is the problem amsoil dominator is a better choice of oils i have witnessed this oil in a burn down condition and upper cylinders were completely spared of scoring this sold me on this product
Hi, great video! thankyou for sharing your knowledge, you have taught me a lot. thank you.😀
I use aviation 100LL from my local airport. shelf life is better than a year.GREAT video. Thanks.
A bit more money but less carb problems good advice
In the description of your channel there is no mention of where you are based (other than Canada) - I would have thought you want to display this at the start and end of every video - great content and it should bring you many customers.
great job with this one back to running like new and nice smile with your eyes at a few funny points 🙂
Probably lower grade oil such as motorcycle oil . You are doing a good job , well done .
Why do you prefer a vacuum test on the cylinder before a pressure test? Great video by the way.
One more advice... NGK spark plugs have that little paper ring because they were pregapped from factory so that paper ring protects the plug from being mechanically regapped in transport, so you don't really need to check the gap with NGK spark plugs. They are just perfect!!
I agree! I use NGK plugs in 90 % of my work here, and I have never seen one come out of the box with the incorrect gap.
PRETTY
Great job, thanks.
Thanks for watching!
You do nice work 😉
You said that air filters can last for years if you clean them!! How do you recommend cleaning the air filter? Love your videos!! You seem like a very sweet person!! Love your disposition!!
Excellent work once again. Those accelerate valves in the carb usually creates problems Not in this case! Actually i believe that they are not necessary at all
perhaps E85 fuel was used in this saw. It is the cheapest fuel. needs new sprocket for sure due to non oiled chain and tight chain
I’ve been fooled by those screens. They look clean, until you try to shine a light thru them. Somehow they manage to get a film on them that completely seals them off, and carb cleaner won’t remove it.
Well done 👍
We have an old saying in Texas YOU HAVE TO BE SMARTER THAN THE EQUIPMENT. Some peoples children are not the sharpest pencil in the box!
I agree ☝️ 😢