Craftsman ys4500 flywheel issue

[Schmidty081]

Hi all - I recently acquired a craftsman ys4500 riding mower that had damage to the flywheel. The key had sheered and cracked the collar of the flywheel. I replaced the flywheel but I’m still having issues. The flywheel spins freely when turning the ignition if not key’d town. The flywheel only gets a spin or so when key is installed. Video at link below - any suggestions or help greatly appreciated!

September 19, 2021

youtube.com

 

[Scrubcadet10]

does the crankshaft spin when the flywheel when the key is not in?

 

[Schmidty081]

The flywheel spins freely when the key is not in. I can turn it while key’d manually with a little resistance

 

[ILENGINE]

I think you are looking at the wrong issue. Install the key and torque the flywheel to the correct spec. Then adjust the valves clearance and then try it. Still don't spin then remove the engine and replace the camshaft after finding all the pieces of the broken compression release. Assuming this the briggs single cylinder engine

 

[StarTech]

But ain't those camshafts still on back order. I am beginning to think they are awaiting a shipment from Neptune. But maybe the Neptunes are waiting on Briggs to pay for them first.

 

[ILENGINE]

@StarTech Yep still on backorder and currently showing pending again. My March ordered carb that was supposed to be ETA on September 2 is also now pending.

 

[Schmidty081]

I appreciate everyone’s quick responses! I did some more digging and I noticed the notch on the shaft had been damaged and the key isn’t holding. Picture attached. Is it possible to deepen the notch so the key doesn’t slip?

 

[Hammermechanicman]

@StarTech Yep still on backorder and currently showing pending again. My March ordered carb that was supposed to be ETA on September 2 is also now pending.

A distinct possibility that Briggs has stopped ordering spares parts or vendors have stopped shipping them parts. I wonder where they are at in the bankruptcy? Maybe they on on one of the hundreds of container ships off the coast of commiefornia. Anybody else paying almost double what they used to for parts?

 

[ILENGINE]

@Hammermechanicman Briggs claimed in their online update seminar that they are using two different sources for all parts to eliminate the parts backlog. Right

 

[bertsmobile1]

I appreciate everyone’s quick responses! I did some more digging and I noticed the notch on the shaft had been damaged and the key isn’t holding. Picture attached. Is it possible to deepen the notch so the key doesn’t slip?

You do not quite get how this works.
The key is purely for timing purposes so the magneto creates the spark at the right time
It is not of power transmission
That is done by the two tapers locking into position.
If there is any damage to the key slots in either the flywheel or the crankshaft then the tapers can not lock so the flywheel will spin freely on the crankshaft
So time to dress the burrs on both with a fine file
Then apply some Brasso or fine valve grinding paste or reel mower blade lapping paste to the taper and lap them together
This is not easy because the flywheel is heavy but unless done the flywheel will never tighten properly to the crankshaft and you will go broke replacing keys.
Then when you put is back, make sure every little drop of grinding paste is gone or that will also prevent the tapers from locking.
It is worthwhile to wrap some rag around the oil seal before hand and make sure it is very clean before refitting or the grinding paste will find its way into the seal & you will end up with a leaking top seal .