I know you said you replaced the seat switch but try unplugging the seat switch and put a jumper wire across the plugin, not the switch in the seat and see if it starts and will engage the blades without killing the motor. You'll just be bypassing the switch and it wont hurt anything, I've seen new switches that were bad. If that doesn't work check your wires on the pto switch and make sure your getting good connections there. You may have to replace the pto switch which is cheap and easy.
#5
wjjones
Some maybe all of the cub z mower seat swithces are double switches if you take it apart it has another switch button inside. I am not sure if the others are this way too, or not. Did you have the brake on when you engaged the pto?
