I am having an issue with a Kawasaki FR730 series motor. It runs well for about 1.5 minutes then coughs a time or too, then quits. a couple of key points:
 

• I can keep it limping by putting the choke to it. 
• If it dies, I can restart it and the symptoms are gone, but they return more quickly.
• If I don't engage the PTO, the symptoms don't appear, at least not for 5 minutes, even under full throttle.
• I tried running with the gas cap loosened, no help.

If choking it helps to keep it running, (even crappy) sounds like s fueling issue.
 
If the carb has a drain bolt, drain and catch what comes out looking for crap.
 
If you have an in-line fuel filter, check it for obstructions..
 
If you can hook up  a gravity feed fuel tank to the engine, and let the fuel
pump pump fuel into another  tank, you can verify the fuel pump is working properly.
 
I strongly suspect your issue is fuel related.
 
.

I will do all that. Thanks