Hey probably a little late but I had the exact same issue. Turns out it was bad gas for me. Lots of particles in the fuel. Pressure washed the inside of the tank. There is a bolt underneath the gas tank to drain. Changed the fuel filter put a bottle of injector cleaner in the new gas incase some got into the injector and she's good as new.

Quote from: Yooper600 on October 25, 2018, 11:25:16 AM
Hello everyone! I'm new to the forum. I cant seem to find anything on the 600 rancher utv.
So This is a long story but I'll try to make it short. The machine starts and runs for about 30 seconds and dies. I can however keep it going when i push the thorottle. The fuel pump kicks on and sounds good when key is turned on. Ive put in a new fuel filter, a new injector, a new map sensor, and a new ecu. Ive swapped around all the relays. if I pull the hose off at the MAP it'll run and idle fine but I notice the exhaust gets hot at the manifold. I'm stumped... could my fuel pump once it does its initial pump to pressure not come back on after start up? I,ve Also cleaned the O2 sensor. my only guess is the fuel pump. I did check the pressure and was getting around 35 PSI. also I un plug the air idle control valve and nothing changes but have one of those on the way too! ANY HELP?
Also does anyone have the specs for the valve clearance? Thanks!