Flywheel Keyway

[pioneerguy600]

Do you have a "pulse degausser"????

No, but my saws start and run when I need them to and really cut wood, they are work saws and that is all I can ask of them. They are not polished and waxed shelf queens, they get dirty and are used in all types of weather from well below freezing, in deep snow and pouring rain, the fine sunny days are a treat around here. I punch a witness mark on the flywheel that lines up with the keyway in the crank, I have never found one yet that has moved from that mark.

 

[HarleyT]

Snow?
Punch a witness?
Yeah, I never could get anyone to believe me when it comes to flywheels......

 

[moresnow]

As already stated, the key only holds the flywheel in position until the nut is tightened. The key would shear off in an instant if the torque from the nut had not set the flywheel solid to the crank taper.

X2.

Normally more of a concern removing items held on a tapered crank!

 

[dynodave]

From
http://www.milfordpower.com/Genuine-Briggs-Stratton-398811-Magnetron-Armatur-p/398811.htm

* Will not work on old cast iron engines. Flywheel has reversed polarity and magnitron can't function.
**Please note, depending on your engine model spec and code date this armature may not fit your model. Please verify all or call us and we can help.

 

[HarleyT]

From
http://www.milfordpower.com/Genuine-Briggs-Stratton-398811-Magnetron-Armatur-p/398811.htm

* Will not work on old cast iron engines. Flywheel has reversed polarity and magnitron can't function.
**Please note, depending on your engine model spec and code date this armature may not fit your model. Please verify all or call us and we can help.

So, I am in disagreement with your buddy in NH, Eh? And he wrote it on his website selling the coil I mentioned, so it must be true. Here is the IPL of an old cast iron Briggs, is this the model series you are referring to?

https://www.partstree.com/parts/bri...ne-rope-starter/carb-a-c-blower-hsg-fueltank/

 

[HarleyT]

https://www.partstree.com/parts/bri...ne-rope-starter/carb-a-c-blower-hsg-fueltank/

coil part number# 298968

 

[HarleyT]

Here is another block, with the same coil, the electronic coil will bolt on this one just fine too.

https://www.partstree.com/parts/bri...gine-rewind-starter/cyl-sump-piston-oil-fill/

 

[dynodave]

The main thing I am trying to convey is that "usually" the magnetic polarity matters. The early Briggs example is one. Later model engines had more likely become standardized and was no longer an issue for points(initially ) and evolving into EI.
On chainsaws the polarity can have an equal effect, good or bad. On this pix:
http://www.arboristsite.com/community/gallery/photos/poulan-3400-sectioned-flywheel.4617/
you can see the construction. south then north ...in normal rotation
Magnetic polarity translates into electrical polarity and since EI are using transistors, which are polarity sensitive, most higher level EI all the components must be of correct orientation.
Pure electromagnetic points systems don't care about polarity.
If I was trying to find substitute EI modules, I would be looking at the original magnet sequence and try to match it to the target saw flywheel. The direction of rotation must also be taken into consideration if a gear reduction saw..Since all my saws are old this is my main area of concern.

 

[HarleyT]

Yes, polarity matters. Found that with the Homelite EZ.
I have put at least 2 of the Briggs #398811 coils on an old Cast Iron Briggs personally, and have sold several more to folks for that purpose, the 2 I did ran fine. No one ever came back saying the coils I sold didn't work either.