you didnt say what engine you are talking about but i expect its a briggs, as far as the gap between the stator and flywheel is concerned i have never used feelers to set the gap (its not as important as the gap on a plug) just use a bit of card about the same thickness as a cereal packet , if you dont get a spark then (make sure the earth for the cutout is not earthing out stopping the spark)there is something wrong with your stator (also when testing try any plug as long as you know it works) try getting a second hand one from a local mower shop we all save them because of how expensive they are ,dont pay more than £10 though. hope this helps :)
benadams
August 2008