Small Engines (Lawn Mowers, etc.): Toro Lawnmower, toro recycler, correct slot

Question
I have a 20016 Toro recycler with 6.5 GTS Tecumseh engine
SN 20071211. I sheared the flywheel key and replaced it but the
engine still backfires. I didn't realize that the blade driver was suppose to have a key in it so I tightened the blade without
the key, would this affect the timing? What else can I check regarding the backfiring? Thanks for your reply. Will the mower run without the blade on?

Answer
Tom

Yes that would affect the timing as the blade and the flywheel are balanced together for the correct timing,put the key way in the blade and check the flywheel to make sure the key way is in the correct slot.Yes the mower will ride with the blade on if all is connected correctly.