Honda GX120 4 HP Engine

Honda GX120 4 HP Engine

1 review
Item Code:
29.0 lb
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**Currently on backorder**

This compact four HP engine from Honda delivers power and responsiveness with a convenient recoil start. As an OHV commercial-grade engine, this model is ready to go to work in a wide range of common applications. This part is compliant with EPA/CARB standards and carries a three year commercial warranty. Weighing just 30 lbs., it can be effectively used in many vehicles and appliances.

Manufacturer Description:

Honda's GX series engines are legendary for superior reliability and performance. And there's no doubt about it: the GX120 lives up to the legend. Lower noise levels, lower vibration, and lower emissions without sacrificing power output or performance.
-Precision camshaft design offers precise valve timing and optimal valve overlap for better fuel efficiency 
-OHV design for increased efficiency and optimal power transfer 
-High compression ratio for better fuel efficiency SMOOTH PERFORMANCE: 
-Precision engineered components result in lower vibration 
-Ball bearing supported crankshaft for greater stability 
-Even quieter than previous model! 
-Large capacity, multi-chamber exhaust system 
-Reduced mechanical noise due to light weight, noise-reducing materials 
-Forged steel crankshaft and rigid crankcase 
-Helical cut gears 
-Sophisticated air intake system 
-Oil Alert 
-New carburetor chamber coating and carburetor filter help to protect against fuel impurities 
-Cast iron cylinder sleeve 
-High quality materials, fit, and finish 
-Dual element air cleaner 
-Fuel Valve 
-Simple throttle control 
-Large fuel tanks and automotive type fuel cap 
-Dual oil drains and fill 
-Easy, convenient, heavy duty control box 
-Easily accessible spark plug 
-Heavy duty recoil starter 
-Ergonomic, easy to grip recoil rope design 
-Automatic mechanical de-compression system EMISSIONS COMPLIANT:
-Lower emissions, same power output! 
-CARB and EPA certified 
-No catalyst necessary


  • Engine type: Air-cooled 4-stroke OHV
  • Starting sytem: Recoil starter
  • Shaft: 3/4" solid keyed
  • Bore x stroke: 60 x 42 mm
  • Displacement: 118 cm3
  • Net power output: 3.5 HP (2.6 kW) @ 3600 rpm
  • Net torque: 5.4 lb-ft (7.3 Nm) @ 2500 rpm
  • PTO shaft rotation: Counterclockwise from PTO shaft side
  • Compression ratio: 8.5 : 1
  • Lamp/Charge coil options: 25W, 50W
  • Carburetor: Butterfly
  • Ignition system: Transistorized magneto
  • Lubrication system: Splash
  • Governor system: Mechanical
  • Air cleaner: Dual element
  • Oil capacity: 0.59 US qt. (0.56 L)
  • Fuel tank capacity: 2.1 US qts (2.0 liters)
  • Fuel: Unleaded 86 octane or higher
  • Dry weight: 29 lbs (13.0 kg)
  • Dimensions: 11.7 in long x 13.6 in wide x 13.0 in high (297 x 346 x 329 mm)
  • Warranty: 3 year commercial warranty (limited to manufacturer defects)
Customer Reviews
5.0 Based on 1 Reviews
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Benjamin M.
  • Was Customer Service Helpful? I didn't interact with Customer Service
  • Ease of Use Very Easy
  • Use Case Lawn & Landscaping
Great running Honda

Bought this to replace the engine on an older mower I redid. Works great. Purrs like a kitten.

Sprayer Depot Honda GX120 4 HP Engine Review