Stihl MS271 why it wont run and how to bypass Carb restrictors!

This is a crazy one and I might end up doing the repair if the Stihl Stealership declines the repair. I will say this, If the "TECH" had done a leak down test he would have found the problem. I don't know how the side of the crankcase is attached as I have not stripped one of these down before. The Owner said he was working the saw and it kinda made a Pop/Hiss and has never run since. Sounds and looks to me like this would be a covered warranty item. Ill give them Ace/Stihl the chance to repair or replace the saw @ no charge to the owner before I put my grubby little mits in it. Thats it for now BUT I have a Echo saw coming in tomorrow. See you then! Shout out to all the the new subs and Thanks so much!

[@andybecker2693]

Those are cylinder port transfer covers. Believe it or not they are more or less glued on or “bonded”. Pretty dumb design. It’s a well documented problem happening all of the time.

[@ZombieDaveAZ]

Thank you Andy, I didn't know that at the time. I'm gonna pin your comment for others. 👍

[@user-lh9xp9lx9z]

Thanks. After taking apart the carb on my MS271 a half dozen times trying to find the problem with fuel delivery, I found my engine is broken as was the one in this video. Not one of the things I checked.

[@HowardNichols-g6q]

I had the same problem with the cylinder side cover. Stihl's only response is that my warranty had expired. I used JB Weld Extreme Heat and put it back together and the saw is working

[@HowardNichols-g6q]

I had the same problem with the cylinder side wall cover. Stihl's only response to me was that my warranty had expired. I pulled the cylinder and reset the cover with JB Weld Extreme Heat. Got it reinstalled and the saw is working

[@roughwater3454]

I got the same problem on a 291 right now this was helpful thanks bud.

[@HowardNichols-g6q]

The JB Weld Extreme Heat held up for running with no load. When I started cutting a large log, the JB Weld failed.

[@ZombieDaveAZ]

@@HowardNichols-g6q I noticed that when I order replacement cylinders (aftermarket) for cut saws they don't incorporate that bonded port plate. Just worth noting. Do you think you will replace the top end?

[@pjoneal12]

Excellent info and demo. Thank you!

[@toddjacobs5660]

Excellent video 👍

[@HowardNichols-g6q]

I will be installing a Hyway cylinder and piston

[@storm501st8]

Those limiter caps can be unscrewed by inserting a hex wrench into the hole. No need to drill out the caps.

[@Canyster]

Thanks for the tip! I was about to go get my drill. Saved me the trouble!

[@jamesedwards6269]

Great video. I was wondering how I would defeat those.

[@pturk8839]

Thanks..It still may need something on the threads so it does not move from vibration

[@BrucesShop]

Good advice. I can't believe the negative comments. My saying as you know similar "If it is broken you can't break it". Warranty or not. You should not have seen it if it was under warranty.

[@ZombieDaveAZ]

A saw out of warranty that runs beats a saw under warranty that just sits there every time. Some peeps just dont get it. I LOVE the keyboard warriors that when you check their youtube channel there is nothing. At least guys like you and I put our selves out there sharing how WE are and what we have learned. So now I'll prolly catch a ration of shit for my comment. Lol 😱

[@bluesteel8586]

Thankyou!!!!

[@vadimosk]

I have the same problem. I little bit weld it in corners and then seal it around

[@zandralopez9238]

Awesome tip. Thank you! Now my tip, why not use a smaller drill bit.

[@ZombieDaveAZ]

Probably me just grabbing what was close. I agree with you. Thanks Z.

[@tobesmith7632]

Those plates are the covers for the transfer ports inside the cylinder. They are baked on. They did have an issue with these ways back

[@tobesmith7632]

Those screws are going to back out put a spring behind each one of them then put them back on

[@danwatkins1524]

Great tip! What are the new starting points for the carb adjusters with the carb stops removed? How many turns out for each? Thanks

[@ZombieDaveAZ]

Start at 1.5 turns out from full seat. Get it to run on its own at idle with the screw that is closest to the engine. "L" Then tweak the H screw. Go full lean til the engine stumbles and then 1/2 turn out. That will keep it rich enough to run and give it power to go through a tree. Up to 10" is good for this size saw.

[@danwatkins1524]

ulitepilot aka Zombie Dave 1.5 turns on all three adjustment screws?

[@ZombieDaveAZ]

@@danwatkins1524 the H and L screws.

[@Aldama0909]

I have a 271, sometimes it works nice and like at the week later it will try to work and I’ll die as soon as I rev, like gasping for air. Change the filter and spark plug already, then leave alone and try again next week and it works again. I don’t know what it is wrong.

[@mmholling87]

Odd question- could you order a different part number carb without the limiter caps and no mtronic stuff?

[@ZombieDaveAZ]

Mark, this is probably one of tbe best questions ever asked of me. The short answer is "I dont have first hand knowledge so I don't know". I do have a opinion that I would like to share if you would be so kind as to indulge me. So lots of guys read the comments and someone will know more than me. The Mtronics by stihl that you mentioned basically was or is the stepping stone leading up to a fuel injected chainsaw. WTF! Yeah I know! BUT the ultimate goal is to take a lightweight hand tool and give it incredible power. Computers making micro-second diagnosis and corrections leaving the operator the sole job of getting the saw to the log and Stihl will do the rest. Mtronics can adjust the throttle, change the timing, add more fuel etc. Sounds like your car doesnt it? How many guys know what to do when the Check Engine light comes on? There rest is a foregone conclusion in my opinion. You will get to know your dealer very well. But because WE never give up I Will go to the dealer and find out if there is a "limp" mode that the machine will default to. If thats the case and I can get a printout of what the operating parameters I will make a video. Do You own 1 of these and if so is it out of warranty? We need spark( @ what ° is the fault? 5?4?3? BTDC) we need fuel ( is it possible to override what Im assuming to be some sort of stepper motor controlled by voltage/pickups from the flywheel magnets?) Compression probably would not be an issue. Now you got my brain going on this. Thanks and sorry Im no help to you. Any more you want to share please do.

[@mmholling87]

ulitepilot aka Zombie Dave thank you for your response! I do not own one of these saws. I wanted a ms261 non m-tronic model (standard carb) but these models are no longer made and to my understanding everything is now m-tronic . I own an Echo CS501p which is close to the professional Stihl stuff but not quite there imo. It is a complete old school style saw and very easy to adjust and fine tune, thanks to no brain box! There are a lot of advantages to electronic controlled engines for Stihl and the EPA but not too many for the consumer. If someone could figure it out and sale carb kits they might make some money.

[@ZombieDaveAZ]

@@mmholling87 I went to the dealer yesterday and asked if you could bypass the mtronics and if others have asked about this. He (guy behind the counter) said "no one has asked to do that. Why woild you want to? Its a great system." I just left the discussion there. I did take the ms271 I was working on and showed him the engine side cover plate. I'm quoting: "Oh Shit! Thats not right!" I asked if it would be covered. The owner of the saw will be happy to know that it IS COVERED. Thanks for getting back to me brother. Stay in touch and have a Merry Christmas.

[@mmholling87]

ulitepilot aka Zombie Dave I can just imagine your conversation with the dealer; you know what they say ignorance is bliss. Thank you again, and have a Merry Christmas and a happy New Years from Tennessee.

[@ZombieDaveAZ]

Hey Mark, There us a guy on youtube that bypassed his mtronics. He replced the flywheel,coil and carb. Then he showed it running and running well. So it CAN be done. Sorry I dont have the link but the video is on here.

[@davessmallenginerevival2847]

You are the 2 cycle master. Great video bud

[@pooper547]

Fantastic video tho i wish you showed how to properly remove the carb to the point you are at in the video. This video isnt much use if you staring at an intact chainsaw

[@ZombieDaveAZ]

Valid point my friend. I don't make regular how to videos very often. It's when I find something unusual that the camera starts rolling. Once I found the engine side plate blown off that's when I started filming. Yeah, pretty much I only shoot a whole start to finish is if someone has a specific problem and I'll shoot it for them. Thanks for the comment

[@pooper547]

@@ZombieDaveAZ i apperciate the reply, i managed to find a disassembly video else where on youtube and managed to fill in the blank. I appreciate what your and you helped me get my chainsaw running nice.

[@crossroads5771]

those side covers are just pressed in, i've never seen them come out before

[@ZombieDaveAZ]

They are not supposed to come off. That was a crazy one to find.

[@cbnx82703]

The problem is if you would of performed the pressure check you would of discovered the fault and not voided his warranty by destroying his carburetor by removing the factory EPA limiter caps, I’m not against removing those caps but not on obviously under warranty equipment...

[@ZombieDaveAZ]

I 100% agree. I should have done the the dealers job. Oh wait!, I don't work for them. This is totally on me now. 🤔 hmmm.

[@cbnx82703]

No you don’t do the apparently incompetent dealers job , but you certainly have an obligation to protect the customers warranty unless you just don’t give a fuck! Shit at least inform him you just fucked him out of his future warranty at possibly another dealer who is competent!!! JMO!

[@ZombieDaveAZ]

Ok. Are we done?

[@brianseaman4094]

I have a MS271 and there is no sign of gas getting into the carb. It's dry even after several pulls on the starter! The problem is that I can't remove the carb because I can't find a socket that fits the two nuts holding the plastic frame onto the carb. They are all too fat to get into the narrow holes where the nuts are located. Does anyone know the size of those nuts?

[@ZombieDaveAZ]

The nuts are 8mm. Take the oldest 8mm socket and grind it down . Start with a thin wall socket to save time. Lots of guys do this.

[@ZombieDaveAZ]

The nuts are 8mm. Take the oldest 8mm socket and grind it down . Start with a thin wall socket to save time. Lots of guys do this.

[@1996509]

Mabye try put a little gas in the barrel put the plug back in and see if it will pop off Is it a new saw

[@stuinit2793]

Your basic run of the mill driver bit extension is 8mm(cant have a slide cover on it like those dewalt ones). I use a screwdriver that takes different bits without a bit in it and fits right down and removes those nuts no problem

[@Budro4764]

Is that the ACE South of Speedway BLVD ???? That is the biggest ACE I have ever seen in my life ...... It takes up almost the block on the road side .......... Is that crankcase broke or does bolt on ???? I haven't tore one down myself either..... They getting smaerter with those limiters for sure ....... Plus Tard Mon Ami ~!~!

[@ZombieDaveAZ]

It wouldnt be nice to expose the tech. Maybe he is new or young or whatever.. I just say. Know what I mean?

[@Budro4764]

Naw I ain't worried about the tech I was just curious as to whether that was same big A$$ store.... That place is huge ........

[@ZombieDaveAZ]

@@Budro4764 LOL no its not that store and I know the 1 you are talking about. I cant find the parts blow up for that side access port. Ill go to stihl and have them show me the blow up on their parts lookup.

[@johnoceanyang5522]

My ms271 won’t start need help. Thank you

[@zachsheffield1325]

STHIL doesn’t want you working on your own equipment even though you already paid for it!!

[@ZombieDaveAZ]

You're right Zach but it's not just Stihl.

[@lukeboehmer5790]

Next time just put a 2 mm Allen where you would typically adjust it.. that way you get full adjustability.. without having to mess with all that bullshit

[@buklau4818]

Dont bad talk ace when you dont know what the stihl engine check is🧐

[@ZombieDaveAZ]

REPEAT: If Ace had done THEIR job it never would have come to me. REPEAT: If Ace had done THEIR job it never would have come to me! Lol.

[@jefferyfunk3598]

Get rid of the potato camera. 😅

[@cbnx82703]

Your knocking Ace when you never pressure & Vacuum tested the unit from the start, probably never was a carburetor issue...

[@ZombieDaveAZ]

Thats a fair statement. BUT if the Stihl/Ace tech had done that it never would have come to me. Agreed? Me doing work on a warranty machine? Thanks for commenting

[@BrucesShop]

@@ZombieDaveAZ I agree buddy. It was broke before you got it. Not fixed by the store. Go for it.

[@ZombieDaveAZ]

I went to the big dealer yesterday. They sell Stihl/John Deere equipment. I showed him the side coverplate that blew off and the guy behind the counter said (AND I'm quoting him) Oh Shit! Thats not supposed to be like that!) best part is that its covered. I took the saw back to the owner @ no charge. $40 tip just for finding the problem and checking with another dealer. But Wait! It gets better, the guy behind the counter asked me if I wanted to work on some of their backlog of saws. I asked whats the problem on getting them fixed? He said ecconomics. Tractor repairs bring in more money than a saw. I told him no thanks,Im good. Lol

[@Budro4764]

Here ya go Coozan ..... I think the cylinder is broken myself ... I have never seen a side plate on a saw engine before ........ stihl.partsmartweb.com/Catdata/EMP_IMG/STGSTH/Images/SERVICE/00590264.PDF

[@ZombieDaveAZ]

I think you are right. Thanks for the link. TONS of great info on there.