I have a 15 HP Craftsman riding lawn mower that uses a Briggs and Stratton engine. Anytime I put the key in and start it, all I get is a clicking sound. The flywheel doesn't turn at all and after a couple of clicks, smoke starts coming out of the engine compartment. So I talked to a guy at the Sears repair place, and he told me to change the starter, solenoid, and flywheel key. So I buy all three and put them in. (Note: The old flywheel key was in perfect condition) I give the engine full throttle and turn the key. The engine suddenly comes to life and sounds as if it had a lot more power than before. I turn the engine off and go inside.
The next day, I try to crank up the engine, and it won't start. The starter motor is turning the flywheel like is supposed to, but its just not cranking up. So I change the spark plug with a brand new one and try to crank it up again. It does nothing. I then open up the flywheel and see that the key is sheared completely in half!!! I change the key, close everything up, and restart the engine. It cranks up fine and runs perfectly. But I turn it off. Let it cool down, and crank it up again, and it won't start again. The flywheel key is again sheared in half!
So everytime I change the key, it works fine. But then the second time I crank the engine up, the key shears. What do I do? I don't think the crankshaft is bad because the original key that I pulled from the mower the first time was fine.