I recently purchased a 2010 Craftsman YTS3000, 21 H.P., 42 inch cut ride mower. The previous owner used it very little however it was left outside under a cover since new. When I arrived to see the machine the PO had already started the mower. I asked him to shut it down for my inspection, when he turned the key to the "off" position nothing happened - the mower continued to run. A few quick flicks of the throttle and the motor sputtered to a stop. No big deal, the mower was in excellent condition otherwise.
A quick pop of the hood revealed the unpleasant smell of mouse urine and a good amount of nesting material, eaten tree nuts and droppings. While not unusual for mice to turn a mower into a motel in these parts, they can do all sorts of damage to the air filter and electrical system among other things. For some reason they love to eat wires and turn air filters into little apartments.
I located a wire junction near the oil dump tube that had a few wires chewed through and attributed the problem with the ignition switch issue to this finding.
After a complete washing and a quick wire fix (solved the switch problem), it was time for a test drive. The first hour or so was fine, no issue, then the engine began surging. Engaging the blades made it sound better however did not solve the issue.
My experience told me to start with the fuel system since I knew the mower had been sitting outside for long periods between each use. Sure enough, after dropping the fuel bowl, I found what looked like clear jelly (coagulated fuel) in the bottom of the bowl. I cleaned the bowl making sure to spray carb cleaner through all of the tiny ports in the carb - this is a very important part of the cleaning process that is often overlooked since it only takes a tiny bit of crud to clog these passages. This solved the problem and the mower runs like new.
A quick pop of the hood revealed the unpleasant smell of mouse urine and a good amount of nesting material, eaten tree nuts and droppings. While not unusual for mice to turn a mower into a motel in these parts, they can do all sorts of damage to the air filter and electrical system among other things. For some reason they love to eat wires and turn air filters into little apartments.
I located a wire junction near the oil dump tube that had a few wires chewed through and attributed the problem with the ignition switch issue to this finding.
After a complete washing and a quick wire fix (solved the switch problem), it was time for a test drive. The first hour or so was fine, no issue, then the engine began surging. Engaging the blades made it sound better however did not solve the issue.
My experience told me to start with the fuel system since I knew the mower had been sitting outside for long periods between each use. Sure enough, after dropping the fuel bowl, I found what looked like clear jelly (coagulated fuel) in the bottom of the bowl. I cleaned the bowl making sure to spray carb cleaner through all of the tiny ports in the carb - this is a very important part of the cleaning process that is often overlooked since it only takes a tiny bit of crud to clog these passages. This solved the problem and the mower runs like new.