Drain fuel tank Refill with fresh fuel. Engine is overfilled with oil Drain oil and fill to proper amount. Engine idles poorly Spark plug is fouled, faulty or gap is too wide Replace spark plug or reset gap to proper setting. Dirty air filter Clean or replace air filter.
Carburetor is adjusted improperly Adjust carburetor.
Excessive vibration Blade is loose or unbalanced Tighten blade and adapter. Bent blade Replace blade. Engine mounting bolt loose or missing. Tighten or replace bolt. Uneven cut Wheels are not positioned correctly.