Small Engines (Lawn Mowers, etc.): John deere 170 problems, john deere dealer, john deere 170

Question
G'day to all ,I am having a small problem with my old faithfull 170 the problem is that when I engage the blades the engine dies then eventually stalls I have tried all the electrical conections that I know of but I am at a loss as to what is wrong any help would be greatly appreciated cheers  

Answer
First question is are we sure that the ignition is turning off when the PTO is engaged.
If so it may be a many of different things as safety switches, engagement switches, bare wires that could be grounded out. Electrical problems can be very fun to figure out. It would be my best advise to take the unit to nearest John Deere dealer for the correct fix to this issue.