December 26, 2025 HomeHondaHonda GX690 FORUM! Dear visitors, now our site has a FORUM where you can ask all your questions and share your experience.
The Honda GX690 is a 688 cc (41.97 cu-in) 90° V-twin cylinder air-cooled four-stroke internal combustion small gasoline engine with horizontal shaft manufactured by Honda Motor Company for general-purpose applications, such as pressure washers, commercial lawn and garden equipment, tillers and cultivators, generators, forestry equipment, construction and industrial equipment, agricultural equipment, small vehicles, water pumps.
The GX690/690R engine has an OHV (overhead valve) design with 90° V-twin cylinders; horizontal type, two-barrel inner-vent carburetor with butterfly valve; digital C.D.I.(Capacitor Discharge Ignition) ignition system with variable timing, a mechanical centrifugal governor and electric starter.
The Honda GX690 motor uses a hemispherical combustion chamber design. It offers a higher 9.3:1 compression ratio, higher power output and greater displacement in a more compact design. The cylinder bore is 78.0 mm (3.07 in) and the piston stroke is 72.0 mm (2.83 in). The GX690 / 690R engine produces 22.4 PS (16.5 kW; 22.1 HP) of maximum horsepower at 3,600 rpm; 17.7 PS (13.0 kW; 17.4 HP) of continuous rated power at 3,600 rpm., and 48.3 N·m (4.93 kg·m, 35.6 ft·lb) of torque at 2,500 rpm.
General information
Engine Specifications
Model
GX690 / 690R
Type
4-stroke, OHV, 90° V-twin
Displacement
688 cm 3 (41.97 cu-in)
Max. horsepower
22.4 PS (16.5 kW; 22.1 HP) at 3,600 rpm
Max. torque (crank PTO)
48.3 N·m (4.93 kg·m, 35.6 ft·lb) at 2,500 rpm
Carburetor
Horizontal type, two barrel, inner-vent, butterfly valve
Cooling system
Forced-air
Ignition system
Digital C.D.I. with variable timing
Lubricating system
Forced feed
Starting system
Electric starter
Stoping system
Ignition primary circuit open
Fuel used
Unleaded gasoline (octane number 86 or higher)
Fuel consumption
6.7 L (1.77 US gal, 1.47 Imp gal)/h
PTO shaft rotation
Counterclockwise (from PTO shaft side)
Dimensions and Weight
GX660
Length, mm (in)
405 (15.9)
Width, mm (in)
410 (16.1)
Height, mm (in)
438 (17.2)
Dry weight, kg (lb)
44.0 (96.8)
Cylinder Block and Head
The Honda GX690 / 690R engine uses integrated cylinder and head, a hemispherical combustion chamber, aluminum push rods with steel tips, racing inspired forged steel connecting rods and forged steel crankshaft with pressure fed crankshaft bearings,
Cylinder block
Compression ratio:
9.3:1
Bore x Stroke
78 X 72 mm (3.07 x 2.83 in)
Sleeve internal diameter
78.000-78.015 mm (3.0709-3.0715 in)
Piston skirt outer diameter
77.985-77.995 mm (3.0703-3.0707 in)
Ring side clearance
Top/Second
0.050-0.080 mm (0.0020-0.0031 in)
Ring end gap
Top/Second
0.20-0.35 mm (0.008-0.0138 in)
Oil (side rail
0.20-0.70 mm (0.008-0.028 in)
Ring width
Top/Second
1.140-1.155 mm (0.0449-0.0455 in)
Connecting rod small end ID
18.006-18.018 mm (0.7089-0.7094 in)
Piston pin outer diameter
17.994-18.000 mm (0.7084-0.7087 in)
Crankpin diameter
44.973-44.983 mm (1.7706-1.7710 in)
Crankshaft journal diameter
39.984-40.000 mm (1.5742-1.5748 in)
Cylinder Head
Warpage (limit)
0.10 mm (0.004 in)
Valve Arrangement:
OHV
Valves:
4 (2 per cylinder)
Stem outer diameter (standard):
INTAKE
5.475-5.490 mm (0.2156-0.2161 in)
EXHAUST
5.435-5.450 mm (0.2140-0.2146 in)
Valve spring free length:
38.3 mm (1.51 in)
Valve lifter internal diameter:
6.010-6.040 mm (0.2366-0.2378 in)
Valve lifter shaft outer diameter:
5.970-6.000 mm (0.2350-0.2362 in)
Camshaft journal diameter:
16.982-17.000 mm (0.6686-0.6693 in)
Cam height:
INTAKE
29.506-29.706 mm (1.1617-1.1695 in)
EXHAUST
29.410-29.610 mm (1.1579-1.1657 in)
Tightening torque specs
Tightening torque specs
Connecting rod bolt
22 Nm; 2.2 kg·m; 16 ft·lb
Cylinder nut
37 Nm; 3.8 kg·m; 27 ft·lb
Oil drain plug bolt
45 Nm; 4.5 kg·m; 33 ft·lb
Flywheel nut
235 Nm; 24.0 kg·m; 173 ft·lb
Oil filter cartridge
12 Nm; 1.2 kg·m; 9 ft·lb
Tappet adjusting nut
7.5 Nm; 0.75 kg·m; 5.5 ft·lb
Governor arm nut
11 Nm; 1.1 kg·m; 8 ft·lb
Fuel pump cover screw
4 Nm; 0.4 kg·m; 3 ft·lb
Oil pressure switch
9 Nm; 0.9 kg·m; 6.6 ft·lb
Service Information
Engine
Maximum speed
3,850 ± 150 rpm
Idle speed
1,400 ± 150 rpm
Cylinder compression
5.0-7.0 kg/cm2 (73-102 psi) at 500 rpm
Valve clearance
Intake valve clearance
0.08±0.02 mm
Exhaust valve clearance
0.10±0.02 mm
Oil system
Oil type
Honda 4-stroke or an equivalent (SE or later)
Recommended oil
SAE 10W-30
Oil capacity
Without oil filter: 1.5 L (1.59 US qt, 1.32 Imp qt) With oil filter: 1.7 L (1.80 US qt, 1.50 Imp qt)
Oil change interval
Every 6 month or 100 Hrs.
Carburetor
Main jet
#118
Float height
15.5 mm (0.61 in)
Pilot screw opening
Cylinder №1: 1-7/8 turns out Cylinder №2: 1-3/4 turns out
Ignition system
Ignition timing
9°-23° B.T.D.C.
Spark plug
NGK: ZFR5F
Spark plug gap
0.7-0.8 mm (0.028-0.031 in)
Ignition coil air gap
0.4 ± 0.2 (0.016 ± 0.008)
ATTENTION! Dear visitors, this site is not a trading platform, an official dealer or a spare parts supplier, so we do not have any price lists or spare parts catalogs. We are an information portal and provide the technical specifications of gasoline and diesel engines.
We try to use verified sources and official documentation, however, differences between sources or errors in entering information may occur. We do not provide advice on technical issues related to the engines operation or repair. We do not recommend using provided information for engines repairing engines or spare parts ordering, use only official service manuals and spare-parts catalogs.
FORUM! Dear visitors, now our site has a FORUM where you can ask all your questions and share your experience.
7 Comments
can i get the catalogue of Honda GX690 22HP
Reply
What oil filter fits the Honda gx690 ???
Reply
Honda 15400 PLM-A02PE
Reply
what is the differences between the GX670 and GX690
Reply
Camshaft one piece
Reply
Good day!
May I know the price of GX690 and estimated shipment here in Philippines?
Reply
Torque spec on intake manifold bolts Honda gx690 engine please.
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The Honda GX690 is a 688 cc (41.97 cu-in) 90° V-twin cylinder air-cooled four-stroke internal combustion small gasoline engine with horizontal shaft manufactured by Honda Motor Company for general-purpose applications, such as pressure washers, commercial lawn and garden equipment, tillers and cultivators, generators, forestry equipment, construction and industrial equipment, agricultural equipment, small vehicles, water pumps.
