[fishbait]

I had the same issue a while back and it drove me nuts trying to figure it out. Turned out the small fuel filter under the left fender was partially clogged. When the rear of the tractor was raised with the stabilizers, the slight forward angle caused the partially clogged filter to be starved of fuel. Changed the filter (not a fun job) and all was well!

All my fault for neglecting the hard-to-get-at filter.