We are renting a house. The homeowner left his Toro Recycler here for us to use so I don't know how old it is. We only used the mower once last year and after that we paid a guy with a riding mower to cut. We want to cut the lawn ourselves this year as the mower is self-propelled and anyway why not? I (the wife) cut the grass last week. We topped up the gas and the mower started okay....it conked out a few times while I was mowing but I managed to get the large yard mowed. Today...the mower starts up after priming but it sounds like it needs to throttle faster and dies out. It needs to be primed each and every time we go to start it. I cleaned the air filter (probably need to buy a new one though) my husband says it sounds like it's the lawn mower isn't getting enough gas. He wants to get some of that gas cleaner additive. I said I thought the gas was maybe too old since we only used it once last year and he says he doesn't think it could be the gas. Any suggestions before I take it to a lawnmower shop? I can't even get 20 feet mowed without it dying. Neither one of us knows anything about motors or engines.

If someone is going to tell me that it's probably the gas and to change it....how do I now that the tank is full?

Thanks.