# Stop-Wire issue



## Hajo (Jan 11, 2019)

Hallo! First time and happy to be here. I hope someone can advise me with an irritating within my Craftsman Snow-Blower Mod. 254880 (MY 2010) with B&S engine 21M314-1475-E1. Any hint appreciated … hard to believe but Bavaria has fallen in snow, so I hope for my blower.

The Problem: Engine will not start because the spark-plug doesn't fire. The plug itself is o.k.. So I assume a fault in the stop-engine-wiring: The switch operated by the small red plastic-key is o.k., the wire and its connection to ground either. But the behaviour of the second wire from the switch, the real Stop-Wire, appears absolutely strange: I measure a connection to ground even if the plastic-key is plugged in, where I expect an „open circuit“. The Stop-Wire itself runs below engine shrouds to the Magnetron-Armature. Unfortunately my B & S repair-manual cannot help.

Can you tell me where this wire is electrically connected within the Magnetron-system? Perhaps "something" is broken or corroded so connecting the said wire electrically to ground. The blower had a standstill of about two years in a carport.

Thank you very much. Let me know, perhaps I can help YOU! I like DIY and generally combustion engines (won't cry this too loud considering Germany's turn to E-Mobility ;-((( )

Hajo


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## cranman (Jan 23, 2016)

The stop wire is attached to the coil to ground it.....try unplugging at the coil. I've heard ( not from my own experience) that having the spark plug disconnected while turning over on the newer engines will destroy the coil, so if the engine doesn't spark with the coil unplugged , maybe swap out the coil.


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## JLawrence08648 (Jan 15, 2017)

I'd remove the wire first at the switch, if that doesn't work then at the throttle, that's where it generally goes?


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## orangputeh (Nov 24, 2016)

on a Honda, you can disconnect the ground wire and it will fire if the stop/kill switch is the issue.


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## Lottstodo (Feb 16, 2018)

Are you sure that it has not sheared a flywheel key. Have you pulled the recoil housing off? if so was there any sign of rodent activity or debris left from them. also look at the condition of the coil armature gap to flywheel, for debris, rust etc.


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## skutflut (Oct 16, 2015)

Hajo said:


> The switch operated by the small red plastic-key is o.k., the wire and its connection to ground either. But the behaviour of the second wire from the switch, the real Stop-Wire, appears absolutely strange: I measure a connection to ground even if the plastic-key is plugged in, where I expect an „open circuit“. The Stop-Wire itself runs below engine shrouds to the Magnetron-Armature. Unfortunately my B & S repair-manual cannot help.
> 
> Can you tell me where this wire is electrically connected within the Magnetron-system? Perhaps "something" is broken or corroded so connecting the said wire electrically to ground. The blower had a standstill of about two years in a carport.
> 
> ...


If the wire from the coil to the switch is grounded, you need to investigate that problem and repair that short circuit to ground. 

You can look for pinched wire or worn insulation that allows the inner conductor to touch metal. 

I think you are going to have to remove the recoil starter assemble and the flywheel to really see whats going wrong. Leaving equipment outdoors for two years can lead to problems.


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## Hajo (Jan 11, 2019)

Thank you so much! You now encouraged me to disassemble the work environment of the coil. Give me a couple of days to look what's the matter. I'll be here again to report on my "adventure".
Hajo


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## 132619 (Nov 20, 2018)

Lottstodo said:


> Are you sure that it has not sheared a flywheel key..


 unlike lawn mowers, it is very rare if at all, to find a snowblower with a sheared crankshaft flywheel key, 

snow blower keys are steel, ver soft cast of a older lawn mower that are made to shear with the blade hits something solid. many newer mowers many now have soft alloy blade adapters between shorter crank shafts, that act just like the older shear keys. which than also use steel flywheel keys


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## Lottstodo (Feb 16, 2018)

Ah yes that is true, however a sheared key was the exact reason that 2 years ago I pick up a Ariens for $30.00 that the dealer told the owner that the coil and or ignition was bad and at dealer prices would well be over $400. to fix. So after checking everything out and $2.00 later ran perfect and netted $450. profit.

And again just this week another blower I got for free had a key sheared when the machine picked up a part of a plow blade, ( no shear pins on auger) owner replaced that one , however auger drive was destroyed .

There have been many more that I have worked on that at some point in time a aluminum key/ and or soft key had been installed as the owner did not know or check the specs, and purchased off shelf at big box or had it laying in junk drawer.

The point is its easy to check and yes they can shear.


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## skutflut (Oct 16, 2015)

If you are in far enough to check for a damaged coil grounding wire, or a bad coil, and the fly wheel is off anyways... it couldn't hurt to take a look if the key is sheared oe bent like it wants to shear, and at every other possible thing that could be cleaned, polished, broken, adjusted, fixed, while your at it. If you don't check, you might be taking it all apart a second time.


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## skutflut (Oct 16, 2015)

Hajo said:


> Thank you so much! You now encouraged me to disassemble the work environment of the coil. Give me a couple of days to look what's the matter. I'll be here again to report on my "adventure".
> Hajo


Remember to *retorque* the nut that holds the flywheel after your reinstall it. Check with Briggs and Stratton for the torque value, its quite important to get that right.

If possible, use an impact tool to remove the nut, They can be difficult to remove with a hand tool since you have to lock the flywheel and you don't want to break any bits of flywheel or cooling fins trying to get the nut loose. 

Some people put a length of rope inside the cylinder and move the piston up to compress the rope to keep the crankshaft from turning while removing the nut from the flywheel. Same process when re-installing and torquing the nut.


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## Hajo (Jan 11, 2019)

*Snow's wellcome now ... not really!*

Hi,
sorry beeing back so late, but due to shipment of a new armature I had to wait. Now I'm happy that after swapping old for new everything is all right and the maschine runs. I don't know what has happend with the old armature, in both cases, old and new, the air gap to the flywheel was within tolerances measured with a specifique gauge. As I mentioned measuring results of the ignitor are a bit strange. I didn't expect too much from the impedances though the secondary high-voltage winding showed a plausible value of 4.5 kOhm. The primary switched winding showed a measurement of about 1 Ohm, while the „kill“-tab to ground showed almost the same. There should be some semiconductor-arrays within the coil-housing making it difficult to decide wether the device is o.k. or not. Unfortunately B&S doesn't provide their customers with detailed diagrams.
Anyway, everything is in order now, thanks for hints and kinks and a useful discussion,
Hajo


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## Hajo (Jan 11, 2019)

Sorry, beeing back so late, but it was due to shipment of my new armature. Swapping old for new, the machine now runs. I don't know why the ignition didn't fire with the previous device, visually I found no differences between the two armatures, the air-gaps where the same. As I mentioned, the electrical behaviour of the ignitor is a bit strange. I didn't expect too much measuring the impedances though the secondary high-voltage winding showed a plausible value of 4.5 kOhm. The primary switched winding showed a value of about 1 Ohm, the „kill“-tab to ground almost the same. There might be some semiconductor-arrays within the coil-housing making it difficult to decide wether the device is o.k. or not. Unfortunately B&S doesn't provide their customers with detailed diagrams.
Anyway, the blower waits for snow from now, myself - not really.
Thank you so much for your hints and useful discussions,
Hajo


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