# Sudden rough idle and cutting out



## milkman2010 (Feb 11, 2016)

I have a Toro 826 about 3 years old. Never had any problems with it. Last week I struck something and it started acting up. It started misfiring and idling rough and curting out. I could restart it but when I switched from IDLE to RUN it would begin to misfire and not run smooth and after a few seconds it would shut off. I could prime it and restart but would get the same thing happen over and over. A couple of times it would work if i let it idle for a few minutes before switching to RUN but it wouldn't last for too long. There doesn't seem to be any gas leaking or anything in the auger. What could it be? The spark plug? I'm lost for ideas. THANKS!

T.C.


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## Blackfin (Jan 25, 2016)

milkman2010 said:


> I have a Toro 826 about 3 years old. Never had any problems with it. Last week *I struck something and it started acting up.* It started misfiring and idling rough and curting out. I could restart it but when I switched from IDLE to RUN it would begin to misfire and not run smooth and after a few seconds it would shut off. I could prime it and restart but would get the same thing happen over and over. A couple of times it would work if i let it idle for a few minutes before switching to RUN but it wouldn't last for too long. There doesn't seem to be any gas leaking or anything in the auger. What could it be? The spark plug? I'm lost for ideas. THANKS!
> 
> T.C.


If the engine stalled when you hit that "something" I'd suspect the flywheel key may have sheared. This results in the spark timing being advanced and the engine can then be difficult to start (may feel some kickback in the recoil starter, for example). If the flywheel moved a lot it may also throw the engine out of balance to produce a noticeable vibration.


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## milkman2010 (Feb 11, 2016)

Blackfin said:


> If the engine stalled when you hit that "something" I'd suspect the flywheel key may have sheared. This results in the spark timing being advanced and the engine can then be difficult to start (may feel some kickback in the recoil starter, for example). If the flywheel moved a lot it may also throw the engine out of balance to produce a noticeable vibration.


THANKS. You may be right about the flywheel key shearing. How do I go about checking this?


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## RedOctobyr (Mar 2, 2014)

Flywheel key would be my thought as well. You would have to remove the flywheel to check it.


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## milkman2010 (Feb 11, 2016)

RedOctobyr said:


> Flywheel key would be my thought as well. You would have to remove the flywheel to check it.


 Thanks. When I remove the cover, will it be obvious that the key is damaged or will I have to remove the flywheel?


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## RedOctobyr (Mar 2, 2014)

No, it will not be visible with just the cover off. You will need to remove the flywheel. 

This is a bit of a discussion topic unto itself. Removing flywheels can be tricky, and if done wrong, you can break something. If you have an impact wrench, for removing the flywheel nut, that is helpful.


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## Blackfin (Jan 25, 2016)

You may be able to see by removing the flywheel cover (the recoil housing) and removing the flywheel nut and starter cup. You can likely then see the key and keyway. On most engines, the two should be lined up. If they look like this:










it may be a sign that the key has sheared and the flywheel has moved.

Having said this, I've seen Tecumseh engines that use funky offset keys like this:










So maybe don't immediately jump to the conclusion that the key has sheared if the offset is small. Perhaps post a picture of what you see and the make and model number of the engine to help determine if what you see is "normal" or "bad."


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## skutflut (Oct 16, 2015)

Hmm, I never saw a key like that, maybe T shaped, but L- shaped? Trying to figure out why somebody would design something like that on purpose. I know there must have been a really good reason.


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## Blackfin (Jan 25, 2016)

Yeah. I worked on a neighbors Tec-equipped lawn mower in the fall and found this. First time I'd seen it too. Seems to be overly complicating a very simple concept. Maybe this is why Tec is no longer around


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## RedOctobyr (Mar 2, 2014)

My apologies, if you can check the flywheel key by removing the flywheel nut, but not necessarily the flywheel itself, that would be a lot easier. 

If it's helpful, I posted a bunch of info about how I removed some Tecumseh flywheels in this thread: 
How hard to remove Tecumseh flywheels?

Impact tools make it easy to remove the flywheel nut. It can be quite tight, and without impact tools, people are tempted to stick a crowbar/screwdriver into the fins of the flywheel, to hold it still while removing the nut. This can break off a fin from the flywheel. 

With impact tools, there is no need to hold the flywheel still. The flywheel's inertia is enough to keep it from turning while the impact wrench spins the nut off. 

You do need to hold it still while re-tightening the flywheel nut with a torque wrench. But at least the re-tightening torque is lower than the torque needed to remove it in the first place.


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## milkman2010 (Feb 11, 2016)

Thanks guys. I just started it up and it ran perfectly fine on CHOKE. I let it run for about a minute then switched to RUN. It immediately began to sputter and cut off. Its a Briggs & Stratton 1150 Snowseries 250cc. Does the symptom still sound like a flywheel problem? If so, I can remove the cover and dig in and get some pics. Or could could it be bad gas or the plug?


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## skutflut (Oct 16, 2015)

You said in your original post that when you hit something, it started acting up.

Did the engine actually stall when you hit that item, or did shear bolts break but the engine kept running? 

If it runs fine on choke, that would indicate a carb problem, running lean, as the choke richens up the mixture by reducing air flow. It it were not for the fact that you hit something, I'm sure everybody would be directing you to the carb, fuel, sparkplug.

The fact that a well running engine changed characteristics after hitting something still points at a possible timing problem, ie flywheel shifted position a bit due to a partly sheared key.

You didn't mention if you start the engine with the recoil or electric start. If you usually use the recoil, have you noticed if it feels "different" when starting, such as being harder to pull over, or kicking back and sucking the starter rope back in hard?

Sorry for all the questions, but the symptoms might help zero in on the problem and avoid disassembling things any more than necessary.


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## Blackfin (Jan 25, 2016)

I'd still look at the flywheel key. I'm theorizing that the richer mixture provided by the choke may allow it to run "better" with advanced timing and when you return it to the normal mixture, it fails.

My reasoning is something like this: An advanced spark occurs while the piston is further down the bore; because the piston is further down the bore the mixture is less compressed and, perhaps, there is less mixture between the plug electrodes (same amount of gas in a larger volume == less density everywhere.) By enrichening the mixture you make a weakly compressed mixture more ignitable. If you return to a mixture closer to stoich (like when you open the choke) the issue returns and it won't run right.

Because it happened after you hit something the carb and fuel system wouldn't be my first diagnostic target (unless what you hit was a passing snowplow and the blower ended up 25 yards down the road, upside down and on fire  )


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## milkman2010 (Feb 11, 2016)

Ahh some good questions guys. It starts normally when I pull the cord. Nothing different there. And no, the machine didnt exactly get tosseed by a tornado. It was like having a hard chunk of ice go through the auger. Just a quick jolt. As soon as I hit it, the snowblower started to run rough then soon cut off.


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## Grunt (Nov 11, 2013)

It is quite possible that some debris from the fuel line, tank or carb was dislodged by the impact and now resides in one of the carb passages. Sounds like a carb cleaning will be the next step.


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## nwcove (Mar 2, 2015)

^ + 1, thats where i would be inclined to focus.


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## skutflut (Oct 16, 2015)

It's probably easiest to start with the easy things first, carb, and rule that out. Flywheel is not that tough, but more of a chore to remove and reinstall, but it will stlll be there to check if the carb inspection and cleaning does not solve the problem. Besides, you can never have too clean of a carb. 

Seems to me I recall my mom always telling me always to have a clean carb, in case I get into an accident and have go to the hospital. SHE would have been mortified it I arrived in an ambulance with a dirty carb.


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## AL- (Oct 27, 2014)

I'm no expert, and long shot...but what if you played with main jet first in case something was stuck there ..


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## cdestuck (Jan 20, 2013)

Sounds like a fuel delivery problem. Maybe as little as pulling the main jet out of the bottom of the float bowl and cleaning up the orifices could clean this problem up. It that doesn't do it, rip off the carb and do a complete disassembly and cleaning.


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## nwcove (Mar 2, 2015)

skutflut said:


> It's probably easiest to start with the easy things first, carb, and rule that out. Flywheel is not that tough, but more of a chore to remove and reinstall, but it will stlll be there to check if the carb inspection and cleaning does not solve the problem. Besides, you can never have too clean of a carb.
> 
> Seems to me I recall my mom always telling me always to have a clean carb, in case I get into an accident and have to the hospital. SHE would have been mortified it I arrived in an ambulance with a dirty carb.


:wavetowel2:geez my mom was more worried about a dirty exhaust !! lol


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## db9938 (Nov 17, 2013)

Some methods to locking up the flywheel, that I've seen, have included removing the spark plug and fishing rope into the hole. 

I would be cautious with this method, as it applies all the torque to the internals.


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## milkman2017 (Dec 3, 2016)

Hello. I am the original poster. I changed usernames. I was unable to figure out how to remove the flywheel this summer. Im not sure how to keep it from spinning. I did change the plug when i was at it. We had our first snowfall today. The machine worked fine blowing snow perfectly for about 15 minutes. All of a sudden it acted up again, skipping, and sounding rough. When I tried to throw snow it cut off. It would start up easily, but after a few seconds it would fail. Im so fustrated and lost about this. Please help if you can...

TC


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## Mike C. (Jan 28, 2016)

You really should check out "Donyboy73" 's snowblower service/repair videos on Youtube.I believe he covers flywheel removal and has several videos on carburetor cleaning.There's nothing better than actually watching a repair or procedure.


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