(quoted from post at 08:12:57 06/12/14) If you disconnected ign kill lead at eng & now have spark,as you didn't say if you have spark with kill lead disconnected,then problem in safety sw's or ign sw/wiring harness.
Do a google search for cub cadet 2146+wiring diagram,from row of images click on left image at start of row,this is probably the wiring diag steve & I are looking at,it may/may not be the correct diagram,see if it matches what you downloaded.
Next click on link below & lookup your tractor in the cub cadet listings,look at drawing for electrical parts & sw's,snap sw(20) on drawing may be what you're looking for in addition it gives you general area on tractor to look for.
cub