Briggs & Stratton 31C707 won’t start after flywheel magnet failure

Is there a reliable source where I can buy the exact same flywheel as the original OEM part? Since both flywheels have the same casting number (215700) but appear to have the ignition magnet in a different position, I want to make sure I get the correct replacement.
 
sgkent said:
yes. The timing is off with the new flywheel. Not just off but way off.

The simplest solution until you can find one, and there are none on ebay that I could find. New is NLA and no one is posting a superceded number. You can pull the rest of the magnets off, use a rotary sander to remove the epoxy that held them on, and run it without charging. The other alternative until you can find a replacement is to take both to a machine shop, have them measure and weigh the two to be sure they are similar in size and weight, then have a new key way cut in the right location. Neither may be optimal and frankly, all bets are off as to whether a new keyway would eventually cause a crack on the old key way, or the new one. Finding a shop that can cut a key may be hard, and even then getting the timing right may not work.

A mower bone yard may have one. There is one on ebay but it is probably as much $$ as a new one.
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Is there a reliable source where I can buy the exact same flywheel as the original OEM part? Since both flywheels have the same casting number (215700) but appear to have the ignition magnet in a different position, I want to make sure I get the correct replacement.
 

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there are many other places. May have to call each one. Trying to help you find one I came across a post on Facebook where someone else is looking for one too. Must be a common failure point.
 
Thank you for looking into it. Do you know of any Briggs & Stratton dealer or reputable supplier that can verify the correct OEM flywheel by my engine model (31C707 Type 3346 G5 Code 120514ZA) instead of just selling a “compatible” replacement?
 
What can happen is you send them the photo of your old flywheel and they can verify before selling you a replacement.

I’d be willing to bet you can find a used flywheel off eBay and visually compare the keyway to the coil magnet on the outside to the listing before purchasing.

You have been given excellent feedback and advice from all the comments.

We all see the issue and now you have a better understanding of the situation.

I’m certain you can find a replacement flywheel, but it might take a bit of time.

Please update us when you have a solution?
 
I believe your part is on eBay now for about $100 delivered.

Briggs And Stratton Flywheel For 17.5hp 31C707

Your photo shows your date code as 120514 so it should be a match.
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A good used flywheel with good ring gear and tight magnets, use before code date 12071800

removed from a 2002 17HP Briggs & Stratton Engine

model 31C707
type-0230 E1
code-020730ZA

parts may need cleaned

last pic is the engine that part was removed from
Buyer responsible for fitment, pictures are part of description

​
 
Last edited:
Just to prove the theory sgkent suggested , clean up the old one and put it back on the machine , if it fires off you'll know the keyway is not cut to the correct orientation . Which is what it appears to be , a machine shop would cost you more than the replacement flywheel and no Guarantee they will cut it in the precise position , even if it's really close , any little offset and your machine will still not run correctly if at all
 
The flywheel must be ordered via the date code as Briggs redesign both the flywheel and crankshaft keyways.

1783334121133.png
One problem is 698281 is NLA so you must upgrade to the newer flywheel and crankshaft if using new parts.
1783334668070.png
And the new setup uses a double length key.

So it is just a lot more involved and expensive to do this.
 
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