Started up the lawn tractor today, and it turned over an started, but belched out some black smoke and then when I let off of the choke, it just got weaker and weaker and stopped. Would NOT restart. On my restart tries, the batter seems to be fine, as it's spinning and whirring the starter as it should. All the spark plug connections seem fine. Further diagnosis / possible issue. 1. Maybe not getting air / enough air? I checked the engine filter and discovered that a mouse had actually gotten in there (HOW?!?) and had a nest of sorts built as well as chewing through the air filter and sponge like material around it. So I cleaned that out, and while I didn't have a spare air filter on hand, I figured "It should RUN without it. Not that I WILL run it, but I can see if it starts to see if that's the issue." It didn't start. 2. NOT out of gas, BUT.....I look at the fuel filter and I don't see any gas in it. Usually, some is visible. So I'm thinking Fuel Pump. 3. I'm out of options as I'm not a small engine knowledgeable person. So is Fuel Pump a really likely suspect, or can you suggest other possibilities? Briggs & Stratton Platinum Line, 24 HP, on a Craftsman YT 4000. Probably 12 or 13 years old if I had to guess. Fairly well maintained, but certainly not obsessively. Thanks for any assistance.