my buddy has 3 of them and i have spent a fare bit of time workin on them. They have basically a big chainsaw carb with the fuel pump built into them, which means they are full of rubber diaframs.(dont use any ethonal blended fuel). also make shure it has an air filter on it, because the intake is so close to the ground it tends to suck in snow. Also the tracks tend to come off the sprockets every once and a while. Other than that its a fun little machine. good luck!