A toro push lawn more when you prime it it will start but as soon as the gas from the primer is gone it shuts off I put in new primer bulb and cleaned the carb and replaced the gas and some times it just won't start at all getting spark just won't start

Hi.
How about that oddly shaped gasket between the air filter box back and the carb? It must be intact or the primer cannot do its job.
Peace,
Clarke