Starter turns the engine until it hits the compression cycle

Craftsman 25587 42" 19 HP Briggs & Stratton Fender Hydro Automatic Riding Mower. Starter turns the engine until it hits the compression cycle (barely one turn of the engine). At that point the engine fails to turn any more. But sometimes just a little turn of the engine is enough to start it up. That happens once in several tries. If it starts the engine runs fine. Sometimes the engine will backfire during start up. Could this be a “valve lash” issue?

Thanks for any advise,

Russell