I have this 42000 21" snowthrower, it is older but in good shape. I used last winter and worked pretty good with a little upkeep. My problem is that when I go down my driveway (hill) the motor startes to stall like it is isn't getting fuel. when I go level or up the driveway, it works fine. The tank is full and no leaks. Im thinking someing to do with carb or fuel tank? any suggestions? want to get it ready for this winter. thanks anyone! m mike