I was running a 18HP B&S Intek Vtwin on a 52" Bobcat ZTR and it randomly felt "different" for about 5 seconds. It was barely noticeable, but it felt like it was depowered or something. Then the blades shut off and the engine kept running. Then about 3 seconds after the blades shut off, the engine shut down. I tried restarting, but nothing gave starter wouldn't even spin. Discovered I had blown a 20 amp fuse so I replaced it. Then, the starter kept clicking trying to start the engine (Sounded like there was no battery power or starter took a crap). After removing the top cover to the engine, I discovered it was actually the engine that had locked up and the starter couldn't spin it. I about pissed because this mower only has 300 hours on it. Long story short, I got a 1 1/4 socket and breaker bar and was able to break the motor free. I immediately changed the oil and filter on the spot and the engine now runs like nothing ever happened. Runs great, however, the PTO still will not engage. There are no more blown fuses, and I kept swapping out the 3 relays it has on the mower to see if one of them was bad. When you are on the mower and you turn the blades on nothing happens. When you are NOT on the mower, but have it running with parking brake on, and try to start the PTO, the mower shuts down (As it should b/c of the seat sensor). So I know the seat sensor and switch work properly. I took a voltometer and hooked it up to the clip that goes on the electric PTO clutch and it shows no voltage coming through. All the wires are wrapped up in insulation and I don't know jack about all that complicated wiring anyway, but what could be wrong? Everything looks fine. I am completely baffled as to what the hell even happened. There must be some correlation between the temporary loss of power/blown fuse/PTO not working/and engine somehow locking up. HELP?