PTO or Mower Issue...works normal then stops

[MyNameIsHank 1]

I have a recently acquired B80 with a few implements and just got all the components to get the mower going.  I have used it twice and it was running great, maybe two hours of use.  On the third mowing everything was going just fine but all of a sudden it was like the PTO froze up and it stopped cutting.  The tractor was still running with no change in engine speed, but the mower and PTO belt were no longer turning.  
 

Any recommendations out there for troubleshooting tips?  Could this be a simple PTO clutch adjustment?  I don’t know the last time this tractor was worked.  I was told I had all the components to use everything but that wasn’t the case so it may have sat a while.

[ebinmaine 73,002]

 

We don't mow with ours so I'll let others help you out there.

 

Great tractor... That little 8 is a wonderful engine.

 

 

[Tuneup 1,452]

Well, that's interesting! You said it was sudden which suggests a bad belt but then the PTO is no longer spinning the belt. Points to PTO but, an adjustment? That wouldn't result in anything sudden. With the engine off, you should be able to spin the PTO by hand to see if the belts engage the deck and the blades spin. If so, engage the PTO, engine still off, and see it can only be spun by spinning the engine as well. Check that the engagement rod provides enough tension to lock that PTO to the engine. That's the basic operation. If #1 fails, check the drive belt tension and the belt inside the deck. If #2 fails, it's PTO time. The experts will be right along but this has been my experience.

[MyNameIsHank 1]

Thanks for your suggestions.  The belt from the PTO to the deck pulley is brand new, has good tension and definitely drives the mower pulley.  I’m going to go back to it though and walk through your steps from scratch.  It would be interesting to hear if someone else has experienced something like this.  Much appreciated. 

[953 nut 60,359]

The only time I have had a similar problem it was the new belt needed more tension than I had given it and it had gotten out of alignment on the mule drive. Lined it back up and tightened it and everything was fine.

[squonk 43,944]

PTO Clutch disc worn out. This would cause the belts to stop with no change in engine speed. Whilst you’re in there, check the bearings on the pulley 

[Lee1977 7,224]

Check the C-clip on the short shaft where the PTO loop is connected. If it has come out of the groove you have lost pressure on the clutch disk. Also a worn ball bearing  on the PTO bell can cause the same.

As said above try shorten the rod one turn to tighten the clutch may be all you need. If it stop again shortly after, you have some other problem with it.

[MyNameIsHank 1]

Great suggestions!  Thanks to all.