After running for about 90 minutes, it slowly begins to lose power. I was in the woods and got it back to garage. A week later tried again and about 40 minutes later same thing. I have a 4 in 1 bucket and when turning and using bucket hydraulics at the same time really starts to lose power. Got it back in garage before it stalled. 50 hours ago ( 7 years ) needed a new pickup tube and fuel line replaced. I opened fuel filter drain and found no water but a little dirt, maybe from original pickup tube. Then pumped bulb and fuel poured out. Only about 1980 hours on it. The shop cannot duplicate problem. Any help would be appreciated. Thanks