GX630/660/690

Raising the bar. On everything.

Honda V-twin engines offer higher horsepower, improved adaptability, quiet operation, and greater fuel efficency. Not to mention a 3 year warranty.

Common Applications
  • Pressure washers
  • Commercial lawn and garden equipment
  • Tillers / cultivators
  • Generators
  • Forestry equipment
  • Construction / industrial equipment
  • Agricultural equipment
  • Small vehicles
  • Water pumps

Features

Fuel Efficient Operation
  • Fuel economy is similar to fuel injection, with the simplicity of carburetion.
  • Digital CDI ignition system with variable timing Learn More
  • Includes a rev limiter to protect against damage from over-revving.
  • Two barrel inner-vent carburetor for more precise fuel metering
  • Insert style rod bearings
High Output Performance
  • Hemispherical combustion chamber delivers rapid combustion Learn More
  • 9.3:1 compression ratio generates high power output without the need for premium fuel
  • Forged steel crankshaft
  • Pressure fed crankshaft bearings
Smooth Performance
  • Integrated cylinder and head Learn More
  • Racing inspired forged steel connecting rods
Exceptionally Quiet
  • High capacity 36 blade cooling fan
  • Aluminum push rods with steel tips - lighter weight, lower vibration, and quieter operation
Proven Reliability
  • High capacity pump facilitates consistent oil delivery Learn More
  • Dual cylindrical air filter
  • Large diameter air intake for superior cooling
  • 3-Year Limited Warranty
  • Oil Alert Learn More
Easy to Use and Maintain
  • Hour meter available
  • Conveniently located controls, with several configurations available based on user preference
  • Automotive-type spin-on oil filter
Easy Starting
  • Automatic mechanical de-compression system Learn More
  • Variable ignition timing
Emissions Compliant
  • CARB and EPA certified
  • No catalyst necessary
Available Options
  • High capacity charging systems
  • A variety of control box configurations
  • Hour meter
  • Dry fuel versions

SPECIFICATIONS

GX630

GX660

GX690

Engine Type Air-cooled 4-stroke OHV Air-cooled 4-stroke OHV Air-cooled 4-stroke OHV
Bore x Stroke 78 X 72 mm 78 X 72 mm 78 X 72 mm
Displacement 688 cm3 688 cm3 688 cm3
Net Power Output* 20.8 hp (15.5 kW) @ 3,600 rpm 21.5 hp (16.0 kW) @ 3,600 rpm 22.1 hp (16.5 kW) @ 3,600 rpm
Net Torque 35.6 lbs ft (48.3 Nm) @ 2,500 rpm 35.6 lbs ft (48.3 Nm) @ 2,500 rpm 35.6 lb-ft (48.3 Nm) @ 2,500 rpm
PTO Shaft Rotation Counterclockwise (from PTO shaft side) Counterclockwise (from PTO shaft side) Counterclockwise (from PTO shaft side)
Compression Ratio 9.3:1 9.3:1 9.3:1
Lamp/Charge coil options 2.7A, 17A, 26A 2.7A, 17A, 26A 2.7A, 17A, 26A
Carburetor Horizontal type, two barrel butterfly valve, internal vent Horizontal type, two barrel butterfly valve, internal vent Horizontal type, two barrel butterfly valve, internal vent
Ignition System Digital CDI with variable ignition timing Digital CDI with variable ignition timing Digital CDI with variable ignition timing
Starting System Electric Electric Electric
Lubrication System Forced lubrication Forced lubrication Forced lubrication
Governor System Mechanical Mechanical Mechanical
Air Cleaner Dual element Dual element Dual element
Oil Capacity 2.1 US qt (2.0l) 2.0 US qt (1.9l) 2.1 US qt (2.0l)
Fuel Unleaded 86 octane or higher Unleaded 86 octane or higher Unleaded 86 octane or higher
Dry Weight 96.8 lb (44 kg) 96.8 lb (44 kg) 96.8 lb (44 kg)
WARNING: California Prop 65 Info

DIMENSIONS

GX630

GX660

GX690

Length (min) 15.9" (405 mm) 15.9" (405 mm) 15.9" (405 mm)
Width (min) 16.1" (410 mm) 16.1" (410 mm) 16.1" (410 mm)
Height (min) 17.2" ( 438 mm) 17.2" ( 438 mm) 17.2" ( 438 mm)

PTO

GX630

GX660

GX690

V type Tapered shaft View Details Tapered shaft View Details Tapered shaft View Details
T type Straight shaft View Details Straight shaft View Details Straight shaft View Details
B type Straight shaft View Details Straight shaft View Details Straight shaft View Details
S type Straight shaft (metric) View Details Straight shaft (metric) View Details Straight shaft (metric) View Details
D type Straight shaft View Details Straight shaft View Details Straight shaft View Details

Performance Curves

GX630 Performance Curve
GX660 Performance Curve
GX690 Performance Curve

The SAE J1349 standard measures net horsepower with the manufacturer’s production muffler and air cleaner in place. Net horsepower more closely correlates with the power the operator will experience when using a Honda engine powered product. The power rating of the engines indicated in this document measures the net power output at 3600 rpm (7000 rpm for model GXH50, GXV50, GX25 and GX35) and net torque at 2500 rpm, as tested on a production engine. Mass production engines may vary from this value. Actual power output for the engine installed in the final machine will vary depending on numerous factors, including the operation speed of the engine in application, environmental conditions, maintenance and other variables.