There is one other,maybe 2 things that are so uncommon,yet devastating, that stop a `ped and are hard to find\ out.
The first,if it hasn't been mentioned, is a sheared flywheel key, which can still allow you to get spark, but not nearly at the right time.
Another,which really baffled me once, is a blown crankshaft seal, which prevents the fuel from being sucked thru the carb., therefore just pumping air in and out. Been there....suffered that! don-ohio