I noticed when I first bought this machine that if I was roading it in 4th. it seemed like the engine would start surging/sputtering. Now when I'm pushing snow it will do this. I hate to say it but other then adding fluids I've never serviced this machine. what could it be???? It runs perfect when idling and running the hoe at full throttle.
Fuel starvation. Running the hoe doesn't put as much load on the engine so it gets enough fuel, but runs low when you push it. Start by changing the fuel filter and open up the old one to see how bad it was. How long have you had it? and how many hours since then?
Also I would check the linkage for extra play at the fuel pump. But do start with the easy things as fuel filters. Also, drain off the petcock at the bottom of the fuel tank to see if you have trash and any water build up.
a little over a year. I might have 25 hours on it