Briggs sheared key

[Alan W.]

Hit a small piece of wood hid in the grass with the push mower and it died. Tried restarting but no go. Sounded like it was trying to kick back. Pulled the flywheel and yep the key had sheared. Didnt have the right size key stock so my son milled one down to size. Briggs forgot to tap the holes for the puller on the flywheel. Back to one pull starting.

 

[ruffdog]

Was the key made of steel or aluminum?

 

[Alan W.]

Was the key made of steel or aluminum?

It was aluminum. The replacement is steel.

 

[stuckmotor]

Last time I removed a flywheel with a puller, the puller had two self tapping screws that went into the holes in the flywheel. I don't believe they were threaded.

I'll leave it to Ruff to explain why the sheared key was aluminum.

 

[Thomas]

They don't make things like the use to.

 

[ruffdog]

Last time I removed a flywheel with a puller, the puller had two self tapping screws that went into the holes in the flywheel. I don't believe they were threaded.

I'll leave it to Ruff to explain why the sheared key was aluminum.

Yes, the aluminum key. When the blade hits something solid and the crankshaft momentarily stops, the flywheel wants to continue spinning. If it had a steel key, it would not shear so all the twisting force goes into the crankshaft. It is easier and cheaper to replace a sheared key than a broken crankshaft.

 

[RandyT]

Yes, the aluminum key. When the blade hits something solid and the crankshaft momentarily stops, the flywheel wants to continue spinning. If it had a steel key, it would not shear so all the twisting force goes into the crankshaft. It is easier and cheaper to replace a sheared key than a broken crankshaft.

Or explain why there are parts of a flywheel embedded into somebodies body parts when it fragments.

 

[RickB]

They don't make things like the use to.

They make some things exactly like they need to. The key sheared, probably saving a bent or broken crankshaft.

 

[Alan W.]

It did crack the flywheel a bit in the keyway. Or the crack couldve been there. Who knows.
Its got a scatter shield on it.

Its weird they put an aluminum key on a light flywheel that lacks a lot of inertia but on the bigger motors with the heavy cast flywheels its steel for the key.

 

[CalG]

With a steel key, the next wood strike will require a new flywheel.\ DTDT and I have the evidence.....

A wise man learns from the mistakes of others.