Troubleshooting - Makita PLM4621N Original Instruction Manual

13. TROUBLESHOOTING

PROBLEM
Engine does not start.
Engine difficult to start or
loses power.
Engine operates
erratically.
Engine idles poorly.
Engine skips at high
speed.
Engine overheats.
Mower vibrates
abnormally.
14
PROBABLE CAUSE
Throttle chock not in the correct
position for the prevailing conditions.
Fuel tank is empty.
Air cleaner element is dirty.
Spark plug loose.
Spark plug wire loose or disconnected
from plug.
Spark plug gap is incorrect.
Spark plug is defective.
Carburetor is flooded with fuel.
Faulty ignition module.
Dirt, water, or stale fuel tank.
Vent hole in fuel tank cap is plugged.
Air cleaner element is duty.
Spark plug is detective.
Spark plug gap is incorrect.
Air cleaner element is dirty.
Air cleaner element is dirty.
Air slots in engine shroud are blocked. Remove debris from slots.
Cooling fins and air passages under
engine blower housing are blocked.
Gap between electrodes of spark plug
is too close.
Cooling air flow is restricted.
Incorrect spark plug.
Cutting assembly is loose.
Cutting assembly is unbalanced.
CORRECTIVE ACTION
Move throttle chock to correct position.
Fill tank with fuel: refer to ENGINE OWNERS
MANUAL.
Clean air cleaner element: refer to ENGINE
OWNERS MANUAL.
Tighten spark plug to 25 - 30 Nm.
Install spark plug wire on spark plug.
Set gap between electrodes at 0.7 to 0.8 mm.
Install new, correctly gapped plug: refer to ENGINE
OWNERS MANUAL.
Remove air cleaner element and pull starter rope
continuously until carburetor clears itself and install
air cleaner element.
Contact Makita authorised service centre.
Drain fuel and clean tank. Fill tank with clean, fresh
fuel.
Clean or replace fuel tank cap.
Clean air cleaner element.
Install new, correctly gapped plug: refer to ENGINE
OWNERS MANUAL.
Set gap between electrodes at 0.7 to 0.8 mm.
Clean air cleaner element: refer to ENGINE
OWNERS MANUAL.
Clean air cleaner element: refer to ENGINE
OWNERS MANUAL.
Remove debris from cooling fins and air passages.
Set gap between electrodes at 0.7 to 0.8 mm.
Remover any debris from slots in shroud, blower
housing, air passages.
Install RJ19LMC spark plug and cooling fins on
engine.
Tighten blade.
Balance blade.