Honda 20.8 Net (continuous) HP Horizontal Engine 688cc (15.5 kW) @ 3,600 rpm | B – Type 4.37″ x 1 7/16″ Keyed Crank Shaft | Elect Start / Control Box
To Complete, A Muffler & Pulley Must Be Added.
Honda V-twin engines offer higher horsepower, improved adaptability, quiet operation, and greater fuel efficiency. 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
GX630
GX660
Engine Type
Air-cooled 4-stroke OHV
Air-cooled 4-stroke OHV
Bore x Stroke
78 X 72 mm
78 X 72 mm
Displacement
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
Net Torque
35.6 lbs ft (48.3 Nm) @ 2,500 rpm
35.6 lbs ft (48.3 Nm) @ 2,500 rpm
PTO Shaft Rotation
Counterclockwise (from PTO shaft side)
Counterclockwise (from PTO shaft side)
Compression Ratio
9.3:1
9.3:1
Lamp/Charge coil options
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
Ignition System
Digital CDI with variable ignition timing
Digital CDI with variable ignition timing
Starting System
Electric
Electric
Lubrication System
Forced lubrication
Forced lubrication
Governor System
Mechanical
Mechanical
Air Cleaner
Dual element
Dual element
Oil Capacity
2.1 US qt (2.0l)
2.0 US qt (1.9l)
Fuel
Unleaded 86 octane or higher
Unleaded 86 octane or higher
Dry Weight
96.8 lb (44 kg)
96.8 lb (44 kg)
GX630
GX660
Length (min)
15.9″ (405 mm)
15.9″ (405 mm)
Width (min)
16.1″ (410 mm)
16.1″ (410 mm)
Height (min)
17.2″ ( 438 mm)
17.2″ ( 438 mm)
Fuel Efficient Operation
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

Smooth Performance

Smooth Performance
- Integrated cylinder and head Learn More
- Racing inspired forged steel connecting rods
Proven Reliability

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 Starting

Easy Starting
- Automatic mechanical de-compression system Learn More
- Variable ignition timing
High Output Performance

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
Exceptionally Quiet

Exceptionally Quiet
- High capacity 36 blade cooling fan
- Aluminum push rods with steel tips – lighter weight, lower vibration, and quieter operation
Easy To Use & Maintain

Easy To Use & Maintain
- Hour meter available
- Conveniently located controls, with several configurations available based on user preference
- Automotive-type spin-on oil filter
Mufflers
HONV2MFLRHIR
High Mount Muffler, RH Exit
HONMUF0497R
Aluminized Muffler + Shield (Starter side) WRX (Must order with manifold)
HONMAN0510R
Manifold, Aluminized (Starter side) WRX (Must order with muffler)
______________________________________________________________________________________________________________________________________________________________________________________________________
Complete Pulleys
PU351716D
3.5 x 1-7/16
DG
PU401716D
4.0 x 1-7/16
DG
WFA150
4.2″ x 1-7/16″
DG
PU451716D
4.5 x 1-7/16
DG
___________________________________________________________________________________________________________________________________________________________________________
PRICE DOES NOT INCLUDE SETUP OR SHIPPING – PRICED FOB FACTORY
GX630 | GX660 | |
Engine Type | Air-cooled 4-stroke OHV | Air-cooled 4-stroke OHV |
Bore x Stroke | 78 X 72 mm | 78 X 72 mm |
Displacement | 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 |
Net Torque | 35.6 lbs ft (48.3 Nm) @ 2,500 rpm | 35.6 lbs ft (48.3 Nm) @ 2,500 rpm |
PTO Shaft Rotation | Counterclockwise (from PTO shaft side) | Counterclockwise (from PTO shaft side) |
Compression Ratio | 9.3:1 | 9.3:1 |
Lamp/Charge coil options | 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 |
Ignition System | Digital CDI with variable ignition timing | Digital CDI with variable ignition timing |
Starting System | Electric | Electric |
Lubrication System | Forced lubrication | Forced lubrication |
Governor System | Mechanical | Mechanical |
Air Cleaner | Dual element | Dual element |
Oil Capacity | 2.1 US qt (2.0l) | 2.0 US qt (1.9l) |
Fuel | Unleaded 86 octane or higher | Unleaded 86 octane or higher |
Dry Weight | 96.8 lb (44 kg) | 96.8 lb (44 kg) |
GX630 | GX660 | |
Length (min) | 15.9″ (405 mm) | 15.9″ (405 mm) |
Width (min) | 16.1″ (410 mm) | 16.1″ (410 mm) |
Height (min) | 17.2″ ( 438 mm) | 17.2″ ( 438 mm) |
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
Smooth Performance
- Integrated cylinder and head Learn More
- Racing inspired forged steel connecting rods
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 Starting
- Automatic mechanical de-compression system Learn More
- Variable ignition timing
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
Exceptionally Quiet
- High capacity 36 blade cooling fan
- Aluminum push rods with steel tips – lighter weight, lower vibration, and quieter operation
Easy To Use & Maintain
- Hour meter available
- Conveniently located controls, with several configurations available based on user preference
- Automotive-type spin-on oil filter
Mufflers
HONV2MFLRHIR | High Mount Muffler, RH Exit |
HONMUF0497R | Aluminized Muffler + Shield (Starter side) WRX (Must order with manifold) |
HONMAN0510R | Manifold, Aluminized (Starter side) WRX (Must order with muffler) |
______________________________________________________________________________________________________________________________________________________________________________________________________
Complete Pulleys | ||
PU351716D | 3.5 x 1-7/16 | DG |
PU401716D | 4.0 x 1-7/16 | DG |
WFA150 | 4.2″ x 1-7/16″ | DG |
PU451716D | 4.5 x 1-7/16 | DG |