Tractor 113 · Spark plug not gapped correctly. · Stale or dirty fuel. Engine Runs Unevenly · Fuel line or fuel filter plugged. · Stale or dirty fuel. · Loose electrical connections. · Air cleaner element plugged. Engine Overheats · Engine air intake screens plugged. · Radiator fins plugged. · Engine oil low. · Engine operated too long at slow idle speed. · Coolant low. Engine Will Not Idle · Spark plug(s) not gapped correctly. · Faulty spark plug(s). · Stale or dirty fuel. Engine Backfires · Faulty spark plug(s). Engine Knocks · Stale or low octane fuel. · Engine overloaded. · Low engine speed. Engine Loses Power · Engine overheating. · Improper fuel. · Too much oil in engine.
· Air cleaner element plugged. · Faulty spark plug(s).