Small Engines (Lawn Mowers, etc.): John Deere Sabre 1538 fairly new, jet adjustment, float bowl

Question
I used the mower all day. Backfired on last 2 starts. Engine starts fine but as soon as brake is released or the blade is engaged the engine cuts out. Will keep running as long as there is no load on engine. Seat safety switch was by-passed, there are 2 other safety switches, one on blade handle other on brake pedal.Not sure if voltage is being drawn down to ground. Battery died, recharged but still has load problem. Any ideas?
Thank You

Answer
 Hello Bob

 1. Sounds to me like you have a Carb that is running to Lean when under a load or you have picked up Trash into the Carb. On the bottom of the Float Bowl is the Main Fuel Jet Adjustment. Turn it Counter Clockwise 1/2 turn.  Ive found the best thing to do in this case is try an adjustment and if it doesnt help then rebuild the Carb.

 2. The Battery problem is fairly common and most times its the Battery having a weak cell that draws the other cells  down.  You might want to Load Test the battery. That will tell you if there's a possible problem.

 Good Luck

 Respectfully

 John