Products Selector

Products » Mid-Range » GX390 Honda Engine

GX390 Honda Engine

GX390 Honda Engine
The GX390 is all new for 2010, featuring more power, quieter performance, lower fuel consumption, and lower emissions. With new features and better performance, the new GX engines establish themselves yet again as the best engines in the business.


Fuel Efficient, High Output Operation

  • Digital CDI ignition system with variable timing
  • Increased compression ratio
  • Precision camshaft design offers precise valve timing and optimal valve overlap for better fuel efficency
  • OHV design for increased efficiency and optimal power transfer

Smooth Performance

  • Precision engineered components result in lower vibration
  • Ball bearing supported crankshaft for greater stability
  • Heavy duty balancer shaft
  • Improved piston design

Exceptionally Quiet

  • Large capacity, multi-chamber exhaust system
  • Improved camshaft and muffler reduce overall engine noise by up to 5 dB
  • Forged steel crankshaft and rigid crankcase
  • Helical cut gears
  • Sophisticated air intake system

Proven Reliability

  • Oil Alert
  • Cast iron cylinder sleeve
  • High quality materials, fit, and finish
  • Dual element air cleaner
  • Fuel Valve

Easy to Use and Maintain

  • Simple throttle control
  • Large fuel tanks
  • Large automotive type fuel cap
  • Dual oil drains and fill
  • Easy, convenient, heavy duty control box
  • Easily accessible spark plug

Easy Starting

  • Heavy duty recoil starter
  • Automatic mechanical de-compression system
  • Variable ignition timing

Emissions Compliant

  • CARB and EPA certified
  • No catalyst necessary

Available Options

  • Low profile versions
  • Gear reduction options
  • Electic start
  • Spark arrester available
  • Charge and lamp coils with multiple output options available
  • Cyclone Air Cleaner available



Engine Type Air-cooled 4-stroke OHV
Bore x Stroke 88 X 64 mm
Displacement 389 cm3
Net Power Output* 11.7 HP (8.7 kW) @ 3,600 rpm
Net Torque 19.5 lb-ft (26.4 Nm) @ 2,500 rpm
PTO Shaft Rotation Counterclockwise (from PTO shaft side)
Compression Ratio 8.2:1
Lamp/Charge coil options 25W, 50W / 1A, 3A, 10A, 18A
Carburetor Butterfly Float Type
Ignition System Digital CDI with variable timing
Starting System Recoil/electric
Lubrication System Splash
Governor System Centrifugal Mass Type
Air cleaner Dual element
Oil Capacity 1.16 US qt (1.1 L)
Fuel Tank Capacity 6.4 U.S. qts (6.1 liters)
Fuel Unleaded 86 octane or higher
Dry Weight 69 lb (31.5 kg)
Length (min) 16.0" (407 mm)
Width (min) 19.1" (485 mm)
Height (min) 17.7" (449 mm)
Product Manuals

Our Partners