Lawn Mower Troubleshooting



Try these lawn mower troubleshooting tips before you spend a fortune at the repair shop.

Engine Won’t Start or Difficult to Start.

  1. Check fuel. Empty tank, stale fuel, or wrong fluid?
  2. Turn fuel shutoff valve to ON position.
  3. Turn ON/OFF switch or key to ON position.
  4. Engine flooded. Wait 20 minutes and try again. Dry off spark plug and try again.
  5. Replace spark plug.
  6. Replace fuel filter.
  7. Check carburetor.
    • Clean if dirty.
    • Fuel line to carburetor may be blocked – clean or replace line.
    • Choke valve not completely closing in carburetor – adjust control cable.

Engine Lacks Power.

  1. Clean air filter.
  2. Replace spark plug.
  3. Choke not completely open.
  4. Exhaust port clogged.
  5. Not enough oil in crankcase (4 cycle engine).
  6. Improper fuel oil mix (2 cycle engine).
  7. Check carburetor.
    • Clean if dirty.
    • Fuel line to carburetor may be blocked – clean or replace line.
    • Choke valve not completely closing in carburetor – adjust control cable.

Engine will not Idle Properly.

  1. Idle speed set too fast or too slow.
  2. Carburetor needs adjustment.

Mower Vibrates Excessively.

  1. Clean debris from under mower deck.
  2. Adjust belts.
  3. Balance blades, pulleys, adaptors, and sprockets.
  4. Engine not mounted securely. Tighten bolts.
  5. Bent crankshaft. Replace with new.
  6. Damaged mower deck. Replace or weld.

Mowing Unevenly.

  1. Inflate tires.
  2. Mower deck unlevel.
  3. Blades bent or unbalanced.
  4. Slow down. Mow in lower speed.
  5. Change mowing pattern.

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