Small Engines (Lawn Mowers, etc.): Power Lawn equipment repair, feeler gauge, stop screw

Question
Michael -  I have a brand new MTD 31CC string trimmer belonging to my son that he never was able to get started out of the box.  I suspected ignition and tore it down and found that the gap between the ignition module and flywheel magnet was approx. .025 or more.(wider than the biggest feeler gauge leaf I had)  Resset gap to about .012 and it has started right up.  Next problem is the idle speed was much too high.  The only idle speed adj, is just a mechanical stop screw against  the throttle control.  Only possible solution I can think of is that since I just made a WAG on the module/flywheel gap, there might have been a more precise procedure recommended by the manufacturer that would have also taken into account either + or - TDC.  The screws holes for the solid state ignition module were of course elongated to allow for the gap setting but also could quite possibly effect timing if the module core centerline was offset somewhat so that it offered a skewed gap with the flywheel face.  I'm just guessing here but it would involve more than shoving the core against a feeler gauge between it and the flywheel which is all I could do.
  Appreciate whatever assistance you could provide.  Thanks,

              Gene Buck


Answer
Hi Gene,

The air gap on the coil should be .012, as you set it.   The method that you used is fine and futher alignment is not needed.  
The idle speed screw that limits the throttle plate from closing, should lower the idle speed, unless there is a lean condition.  Usually present, are the normal high and low speed mixture screws.  Sometimes they are covered with plastic caps to prevent tampering.  If not present, look for a leak in the carb to intake gasket.  

Let me know how you make out.
Michael