I need help ASAP.
 

Well I was mowing at my girlfriends house with my 680. I got off the tractor to check the height of the deck because I don't have a position sticker on it. So I get off the tractor, check it get back on and fliP the PTO on. As soon as I flip the PTO on it starts running horrible, almost like its running out of has, by it has half a tank. So I parked it for a little bit and tried it again later. Still does the same thing. I tried it two more times after first discovering it. But still the same thing. HopE this helps. Thanks in advance.

Must be electrical...Shorting/grounding out? :bigthink:

Try disconnecting the PTO at the wire connector. Then flip the PTO switch on and see if it still has the same condition(s). If it does, rule out the PTO. If it does not, then you have a PTO issue.

Baring any pulleys or spindles locked up, I wouldn't think it would be a PTO. Seeing that its electrical it would short out, not really having anything to do with the fuel, governor or the engine.

If you run the unit at top no load speed, does it run fine?

Running at top no load speed when you flip the PTO switch on this is when the problem starts?

If so its a fuel problem 99% of the time. As your now running against the Governor at top load speed

Vince_O, it does do it when I put it at top speed and engage the PTO, no load. Only when I fliP the PTO on is when it does it. And Roland, I'll try that to see if that works. I was thinking last night that maybe one of the safety interlock wires tied into the switch was bad or something but I didn't want to mess with it without getting further advice.

I hope you aren't engaging the PTO at full throttle with the deck connected. That will destroy the clutch, belts, etc. Electric PTOs need to be engaged at the lowest possible RPM.

I always engage it at low rpms, but i was so frustrated last night trying to figure it out that i did engage it a couple times at high rpms.