Originally Posted by DaveC
I started on a ride when the motor started chugging, bucking and backfireing
Good fuel flow... could I have sheared the woodruf key?
Now I'm bummed
Bad fuel, wiring issue, fouled/ failed spark plug, spark plug wire, crap in the carburetor clogging up the fuel jet.
If you are not running an HT engine, then yes, a sheared woodruff key on the flywheel could cause what you are experiencing. If you are
running an HT engine, I highly doubt that you sheared the woodruff key on the mag rotor. That said, some folks have found that the key was never installed by the factory or that it was at least placed on the shaft but pushed out upon installation of the rotor and found it magnetically stuck to the back of the rotor. Either condition can let the rotor rotate on the shaft and throw off the ignition timing.