Small Engines (Lawn Mowers, etc.): lawnboy push mower, defective coil, ign

Question
a friend recently gave me his old mower because it wouldnt start for him i figured it was either the spark plug or carberater so i cleaned the carb. and replaced the spark plug but it still doesnt start. when i try to start it it sounds like it might start but then just dies. the mower has alot of old grass stuck to it, could there just be a part that isnt moving properly because of the grass? or do i need a diffrent part for it?

Answer
garrett, I need to know the model-type-trim or Mfg of the engine. Basic trobleshhoting is:  Is there spark, if none look for broken-grounded wires or defective coil. If there is spark -- and a tiny amount of gas is added to the throat of the carb, and does not run, sheared flywheel key..Electronic ign...If runs and quits.....a gas problem exists......Best I can do blindly.......Bob