I have to admit that I sheared one on a Kohler twin when I turned the key to the start position while the engine was running. Jammed the bendix so hard that the flywheel just stopped. Didn’t expect that. Lucky I didn’t break the starter shaft or a rod off. Learned a lesson that day.
bertsmobile1
Lawn Royalty
I find that weird than almost every mower will allow you to do that when a simple relay would prevent it .
Now back to the OP
Tapers are easy to damage so get some very fine lapping paste ( I use Brasso ) and lap the flywheel to the taper .
Keep on going till it is nice & shinny
What do you mean by tapers? You mean the Sledge style tapered press fit of the crankshaft into the matching shape on the flywheel?.
I don't worry about those getting damaged at all. It makes little difference. Lol
Just stick it on and hold it in the right place and tighten it up and actually it'll be fine.
Those keys aren't even there to stop it from spinning but rather just to line it up during the manufacturing process.
At least this is 95% the case.
Also, you can just line it up and get something to drive down into there while you're holding it.
A nail, a screw with the head cut off, a cotter pin shortened a little bit.
It don't matter!
I just put a new Briggs push mower engine back together yesterday with a couple pieces of cotter key in there because I didn't really feel like taking the flagpole off of another one to scavenge an actual Briggs key.
You are very correct and rarely does hitting anything cause these to shear.
What usually does it is somebody messing around with the ignition switch turning it on and off or a flaky switch or even more likely when their seat switch isn't adjusted properly or it's bent or something and they're bouncing around causes the ignition to go on and off.
Engines are meant to screw with them like that.