# Possible flywheel key break Model 12527HV?



## crmoores (1 mo ago)

Tried the electric start and it’s like something broke - the flywheel revved up but it’s like the flywheel key may have broken. Tried the manual pull. same thing.
Is it difficult to get to the flywheel key to inspect it without a puller or special tools?


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## dbert (Aug 25, 2013)

Welcome.
Sheard flywheel keys are very rare on snowblowers in my opinion. There are belts between the engine and the other mechanicals to absorb shock loads. Different from a mower blade that is mounted to the engine crankshaft and it hits a stump or whatever.
Since the issue is with the engine you may want to expand your queries toward the engine. Looks like that machine uses a 291cc LCT engine.


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## dbert (Aug 25, 2013)

Perhaps you have something like an exhaust valve stuck open and without any compression, things are just spinning easily.


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## scrappy (Dec 7, 2014)

A have seen sheared keys on snow blowers. My boss brought his clone powered in for me to get it running. Key was sheared. He said he pulled the cord and "it locked up for a second".

The carb was full of crap and float stuck, so he must have hydrolocked it with gas. New carb and a keyway sent him on his way.


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## JLawrence08648 (Jan 15, 2017)

I agree with dbert, very rare to have a sheared flywheel key if not impossible. Do a compression test to check for the valves not sealing.


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## Oneacer (Jan 3, 2011)

In all my life, I have never come across a sheared flywheel key on a snow blower.


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## Sam Am I (Oct 28, 2021)

If the flywheel nut is torqued properly, probably never have it happen agreed, BUT if that nut is loose'ish(not 75 lb-ft, but 30/40 lb-ft for example), it'll happen!! Just sheared one the other day, impact wrench snugged the nut on, no load, just started it and it sheared....POOF! If that nut somehow gets loose'ish(heat, age, cold, vib, stress whatever cause), I wouldn't bet on it not happening.........The tapered fit of the flywheel and the crank shaft when pressed/fit together properly is what mainly keeps the flywheel from spinning on the crank, not so much the key-way, but if the fit isn't true and tight, then all the forces are directed on the small relatively soft key which typically fails almost immediately.


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## crmoores (1 mo ago)

so the reason I was asking about the key is the sudden “let go” from the flywheel. The flywheel took off (revved up) when it let loose, and when I try the electric start or manual it feels like the flywheel is not connected to whatever it was. Is there a belt between the flywheel and engine that may have broken? This blower is a few years old and treated well…
Thanks for the forum by the way!


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## Sam Am I (Oct 28, 2021)

crmoores said:


> Is there a belt between the flywheel and engine that may have broken?


No, the flywheel is bolted to the crankshaft(engine)..........If you electric start it and the piston isn't moving up and down(engine pulley in front isn't rotating), but the flywheel is spinning during cranking, the key is sheared or the crank shaft is broke.

*Sorry for the mess, but here's link to perhaps get the picture*











20211121_105244.jpg







drive.google.com





Woodruff key( a good one) is sitting in crankshaft channel @12 o'clock


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## vangasman (Oct 21, 2021)

I hope they haven't gone cheap and made the flywheel with the key a integral part. Some smaller engines are going this route.


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## crmoores (1 mo ago)

Well that is very helpful, thanks! It jives with what I am experiencing.
I’ve never taken the flywheel cover and flywheel off but I will attempt to get at it before the storm hits! I’m not finding instructions on accessing the crankshaft and key…


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## guzzijohn (Mar 31, 2014)

What engine is that? Bean counters are expert at pushing design features that guarantee sales of parts or new engines.


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## crmoores (1 mo ago)

Sorry, what I should have asked is how can I tell if the engine pulley in front isn’t rotating? Can Inaccess that?

And I skipped over dbert’s point, sorry…Question - could the crankshaft still be turning (at what sounds like higher rpm’s), but the belt connecting the crankshaft to the mechanicals broke? I have not replaced the belt on this unit…


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## Sam Am I (Oct 28, 2021)

crmoores said:


> Well that is very helpful, thanks! It jives with what I am experiencing.
> I’ve never taken the flywheel cover and flywheel off but I will attempt to get at it before the storm hits! I’m not finding instructions on accessing the crankshaft and key…


Sure, but like others here have said, might not be the flywheel key..........First I think I'd pull the front cover off (easy peasy two bolts held on plastic cover typically), after ya pull the cover, you'll see the other end of the crank shaft with a pulley and some belts wrapped around the pulley. Crank it and watch that pulley, it should spin sorta fast while cranking. If you don't guess/estimate that that front pulley is spinning so well, might pull the spark plug out next and crank it again watching that same front pulley, if it seems to spin much better, might have a sheared key, loose'ish flywheel.

At any rate, pulling off the flywheel cover is pretty easy, maybe 6 or 8 bolts around the shell/cover and they typically fall right off.

Pulling the flywheel is easy too, impact the nut off(if it isn't already loose) and remove the pull rope cup and fan, spin the flywheel nut back on the crank shaft by hand stopping when the nut's top edge is flush with the crank shaft end(nut still hand spin loose typically)leaving a small gap/distance between the nut and the flywheel.

Using a nice big ole fat flat blade screw driver, slide it in under and between the flywheel's ring gear and the engine block sorta loosey goosey still, but when twisted(not pried), the blade will put upward pressure on the flywheel.

While twisting the screw driver putting a desent upward force on the flywheel, strike the flywheel nut flat as you can across it's face with the flat face of a 5lbs mallet for example(you don't have to kill it, let the mallet do the work plus 2). Usually one or two or three blows and the flywheel should just pop up/off the crank shaft.


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## Sam Am I (Oct 28, 2021)

crmoores said:


> Sorry, what I should have asked is how can I tell if the engine pulley in front isn’t rotating? Can Inaccess that?


See just above



crmoores said:


> Question - could the crankshaft still be turning (at what sounds like higher rpm’s), but the belt connecting the crankshaft to the mechanicals broke?


Sure, when you've pulled the front cover, you can inspect these belts


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## crmoores (1 mo ago)

Ok I removed the front cover and found the crankshaft is turning. The rear belt is turning, while the front belt is not broken but is loose and not turning. Tried to attach a video but no luck…

[EDIT] Or is that belt loose just because the auger is not engaged?


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## crmoores (1 mo ago)

Well I tried using the electric start just to be sure, and that appears to have become “disconnected“ as it just spins with no effect on the engine.
I tried using the recoil handle to start it and it turned the rear belt, but then the engine “froze”. The recoil will not pull, and I tried the electric start (just a very quick try) and it sounds like the engine is seized…Ug…


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## Oneacer (Jan 3, 2011)

ughhh .... that's not good


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## Sam Am I (Oct 28, 2021)

crmoores said:


> Ug…


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## guzzijohn (Mar 31, 2014)

Plastic gear on starter not engaging due to teeth worn off or the engagement parts not working. That's a separate problem. If it turned over with the recoil but it suddenly stuck your engine isn't necessarily locked up the recoil may have. How long since it ran? Have you been trying to start it many times with electric?(that could've killed starter gear). If it turned part way and stopped something like a stuck or broken valve may be in the piston' s way. Was it a perfectly running machine that suddenly wouldn't work or it's been sitting 1-10 years won't pop right off. People will sometimes crank a machine until the starter breaks or burns out or they have the big one from recoil exertion. The history of the problem is cloudy. When you initially said flywheel spun free could you see that through the recoil opening or just hear the starter run? The belt pulley moved? Remove spark plug and try rotating pulley by hand. Long winded reply for what may be a simple issue.


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## Sam Am I (Oct 28, 2021)

guzzijohn said:


> If it turned over with the recoil





crmoores said:


> The recoil will not pull, and I tried the electric start (just a very quick try) and it sounds like the engine is seized…Ug…




@crmoores

Might want to pull the flywheel cover(includes re-coil guts), take the plug out and rotate the flywheel by hand....The flywheel should rotate by hand pretty easy for 360+ degrees nice and smooth, no clunks or clanks. This should put it to bed or not.....


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## laser3kw (Feb 11, 2018)

Broke a rod. Now, after start attempts, rod carnage has jammed up the crank. If you get the crank to turn, take the spark plug out and stick a plastic straw down the hole and turn crank over. Straw should move up and down if the piston and rod are still attached to the crank
Being a Husqvarna, it probably has a MTD Powermore engine. You could get a HF engine and swap over you flywheel & electric start. Maybe some other unique items.


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## guzzijohn (Mar 31, 2014)

Rods only break when the engine is running.


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## crmoores (1 mo ago)

Sorry for the delayed response folks..
So after thinking it through, we removed the electric start (after dissembling much of the blower) and found the electric start cast housing had been shattered and the gear was “floating around”. No real damage to the main gear or other components fortunately. We removed the start unit,taking care to fashion a cover from sheet metal for the hole where the start unit was.
No more electric start, but the unit starts very easily with the recoil start. Images below, hopefully!

Thank you all for your help and advice, great forum!


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## Oneacer (Jan 3, 2011)

Yeah, many times the starter on units loosen up, causing all sorts of problems, as you can see

Glad you got it all taken care of. Even though most of my units have electric start, I never use them. I always use pull start.

Now just keep a look out for a starter at a good price at your leisure ..... If you do replace it, use some luck washers, as well as some Loctite Blue 242.


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