Toro z4200 turns over no spark. New switch,relay,plugs blade switch,alternator and fuses. Ran till alternator shorted out.

SOURCE: Dual blade mower leaves uncut strips between blades.

Had same uneven mowing problem with new Toro Z4200 XTR mower. Problem was one side of the U-shaped rear deck hanger rod had popped out of its chassis mount (did hit something with mowing deck). Removed hanger chassis mount & its bolt. Put end of U-shaped rear deck hanger rod back in the chassis mount and remounted hanger chassis mount & its bolt. Z4200 now cuts lawn evenly again.

SOURCE: replaced alternator and battery is good but not charging

I found the problem YEAH. It was the fuse that is in the side of the fuse box under the hood, Its where the battery wire from the alternator connects thru a fuse to go to the battery, Its one hundred and something volt fuse. It took care of the problem instantly.... Thank you all for your replies...

SOURCE: I need a toro z4200 drive belt diagram as my belt

I have the same problem and juts figer that out and put back on but still not working,

SOURCE: xterra car quit running. had no spark @

Yes, there is fuel pump relay, which is generally located on the passenger side kick panel. But in your case, the fuel pump relay on 2002 model Xterra is indeed located under the dash around the steering wheel, but no you don't need to remove the cover just lay in floor and you can see it, it will slide off a bracket and you can remove and replace it.
Good Luck!

SOURCE: Toro Z4200 Kohler engine. I was mowing and shut the mower down. When I tried to restart it would not start, not even a single fire. Starter works fine.

check for spark is the wire on the spark plug is the plug good check for fuel flow possible electrical short