But this past weekend I mowed the lawn for about 1 hour and 30 minutes and it never stalled. The only difference is I moved the mower deck height up two notches. Up to 2.5 from 1.5.
So this brought back some memories. The stalling didn't happen until I had sharpened the blades, taking them off and then putting them back on. After doing this is when the stalling began to happen.
What I remembered is that, with one of the blades, I was having a very hard time loosening the bolt that held it on. I usually stick a 2 by 4 in between the blade and the mower deck to prevent the blades from turning as I loosen the bolt. This one stubborn bolt would not budge. So as I applied more pressure the bolt started turning but it was just turning, not being loosened. Even with the blades unable to move, the bolt was still turning.
I finally got the bolt off by taking the 2 by 4 out and putting a wrench on the top side of the deck to stop the bolt from turning, which I should have done in the first place. I sharpened the blades and put it back on.
Then the stalling started.
Did I mess up that bolt and other things to make the engine have to work a lot harder to turn that blade? It has been greased.
That's the only thing I can think of at this point.