Kawasaki FH641V problem

I've got this motor on a Husqvarna riding mower.

After the mower has sit for a few days, it is hard to start and actually pushed gas/oil out muffler, smokes, and hard to start.

After running for 15-20 minutes, the motor dies like it is running out of fuel. I can keep it running for a couple of minutes by playing with the choke. It generally starts back fairly easy, but dies within 2-5 minutes.

I've changed the fuel filter

What else can I look at?

Thanks in advance