Makita PLM4120 User Manual (English)

Questions and Answers:

J
James PerezJul 30, 2025
What to do if my Makita Lawn Mower engine is hard to start or loses power?
- B
  Billy FigueroaJul 30, 2025
  If your Makita Lawn Mower engine is difficult to start or loses power, it could be due to several reasons. The fuel tank might contain dirt, water, or stale fuel; in this case, drain the fuel, clean the tank, and fill it with clean, fresh fuel. Also, the vent hole in the fuel tank cap could be plugged, so try cleaning or replacing the fuel tank cap. A dirty air cleaner element can also cause these issues, so clean the air cleaner element.
I
ithompsonAug 8, 2025
Why is my Makita Lawn Mower engine overheating?
- R
  rmooreAug 8, 2025
  If your Makita Lawn Mower engine is overheating, it might be due to restricted cooling airflow. Remove any debris from the slots in the shroud, blower housing, and air passages to ensure proper ventilation. Another possible cause is an incorrect spark plug. For the PLM4120 model, install an RC12YC spark plug and ensure the cooling fins are on the engine. For the PLM4620 model, use an RJ19LMC spark plug and cooling fins.
E
Emily ShawAug 12, 2025
Why does my Makita PLM4120 vibrate abnormally?
- M
  Melissa StevensAug 13, 2025
  If your Makita Lawn Mower vibrates abnormally, it could be due to a loose cutting assembly. Try tightening the blade. Alternatively, the cutting assembly might be unbalanced, so try balancing the blade.
K
khooverAug 17, 2025
What causes a Makita Lawn Mower engine to operate erratically?
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  elizabethgonzalezAug 17, 2025
  If your Makita Lawn Mower engine operates erratically, it could be due to a defective spark plug. You should install a new, correctly gapped plug. Another possible cause is an incorrect spark plug gap; set the gap between the electrodes at 0.7 to 0.8 mm. A dirty air cleaner element can also cause this issue.
T
Timothy KentAug 21, 2025
How to fix a Makita PLM4120 engine that idles poorly?
- A
  Alvin AbbottAug 21, 2025
  If your Makita Lawn Mower engine idles poorly, it could be due to a dirty air cleaner element. Also, air slots in the engine shroud might be blocked, so remove any debris from the slots. Additionally, cooling fins and air passages under the engine blower housing could be blocked; remove any debris from these areas.
B
Brian Carey Jr.Aug 26, 2025
Why does my Makita PLM4120 Lawn Mower engine skip at high speed?
- A
  April LamAug 26, 2025
  If your Makita Lawn Mower engine skips at high speed, the gap between the electrodes of the spark plug might be too close. Set the gap between the electrodes at 0.7 to 0.8 mm.

Makita PLM4120 Specifications

General

Type	Push lawn mower
Cutting width	410 mm
Grass catcher	Yes
Cutting system	-
Number of wheels	4 wheel(s)
Recommended lawn area	1000 m²
Maximum cutting height	75 mm
Minimum cutting height	20 mm
Grass collecting volume	50 L
Cutting clearance adjustment	5
Motor power	2.8 hp
Power source	Gasoline