When nearly completeing mowing my yard,(nearly an acre)it started to sputter and miss like it was running out of fuel,after checking fuel level,not the problem,when I engage deck,it quits,and when I disengage,runs fine,where is this safety switch to replace?

There are usually at least 3 safety switches on most tractors. The one that's killing you is the one on the blade engagement linkage. With a model number I might be able to post a diagram, it's the switch that stops you from starting a mower with the blade already engaged