The Honda GS65 is a 240 cc single-cylinder air-coolled 4-stroke internal combustion small gasoline engine manufactured by Honda Motor Company since 1975 for general-purpose applications.
The Honda GS65 engine has a slide valve (L-head) design and camshaft driven by a single row chain driven by the crankshaft. It has an electric starter motor, horizontal carburetor with butterfly valve and high voltage ignition.
The GS65 produced 6.8 PS (5.0 kW) at 4000 rpm of maximum output and 12.2 Nm (1.24 kg·m) at 3000 rpm. The dry weight of the Honda GS65 engine was 30.0 kg (66.0 lbs). A 72 mm (2.8 in) cylinder bore and 59 mm (2.3 in) piston stroke give the engine a total of 240 cc (14.6 cu.in.) of displacement. The compression ratio is 6.1:1.
General information
Engine Specifications
Model
GS65
Type
4-stroke, side valve type (L-head), single cylinder
Displacement
240 cm 3 (14.6 cu-in)
Max. horsepower
6.8 HP (5.0 kW) at 4000 rpm
Max. torque
12.0 Nm (1.24 kg·m) at 3000 rpm
Carburetor
Horizontal, butterfly valve
Cooling system
Forced-air
Ignition system
High voltage ignition
Lubricating system
Splash system
Starting system
Electirc starter motor
Stoping system
Ground switch
Fuel used
Unleaded gasoline (octane number 86 or higher)
Fuel tank capacity
6.9 L (1.6 US gal., 1.5 Imp. gal.)
Fuel consumption
300 g/HPh (0.67 lb/HPh)
PTO shaft rotation
Counterclockwise (from PTO shaft side)
Cylinder Block and Head
Cylinder block
Compression ratio:
6.1:1
Bore x Stroke
72 X 59 mm (2.8 x 2.3 in)
Sleeve internal diameter
72.00 mm (2.835 in)
Piston skirt outer diameter
71.97 mm (2.833 in)
Ring width
Top
2.48 mm (0.098 in)
Second/Oil
2.49 mm (0.098 in)
Ring Side Clearance
Top
0.02 mm (0.0008 in)
Second/Oil
0.01 mm (0.0004 in)
Piston pin outer diameter
19.0 mm (0.748 in)
Cylinder Head
Warpage (max)
0.2 mm (0.01 in)
Valve Arrangement:
OHV
Valves:
2
Stem outer diameter (standard):
INTAKE
6.97 mm (0.274 in)
EXHAUST
6.93 mm (0.273 in)
Valve guide internal diameter
7.00 mm (0.276 in)
Cam height:
INTAKE
35.18 mm (1.385 in)
EXHAUST
35.18 mm (1.385 in)
Tightening torque specs
Tightening torque specs
Fuel tank (8 mm nut, bolt)
20-28 Nm; 2.0-2.8 kg·m; 14.5-20.2 ft·lb
Side cover (8 mm bolt)
20-25 Nm; 2.0-2.5 kg·m; 14.5-18.1 ft·lb
Cylinder Head (8 mm bolt)
20-25 Nm; 2.0-2.5 kg·m; 14.5-18.1 ft·lb
Cylinder (6 mm bolt)
8-12 Nm; 0.8-1.2 kg·m; 5.8-8.7 ft·lb
Cylinder (8 mm bolt)
20-28 Nm; 2.0-2.8 kg·m; 14.5-20.2 ft·lb
Camshaft center (6 mm bolt)
10-15 Nm; 1.0-1.5 kg·m; 7.2-10.8 ft·lb
Starter pulley (6 mm bolt)
8-12 Nm; 0.8-1.2 kg·m; 5.8-8.7 ft·lb
Flywheel (17 mm nut)
70-80 Nm; 7.0-8.0 kg·m; 50.6-57.9 ft·lb
Muffler (6 mm nut)
8-12 Nm; 0.8-1.2 kg·m; 5.8-8.7 ft·lb
Carburetor (6 mm nut)
8-12 Nm; 0.8-1.2 kg·m; 5.8-8.7 ft·lb
Maintenance data
Engine
Cylinder compression
4.0 kg/cm2 at 450-600 rpm
Tappet clearance
Intake valve
0.06-0.11 mm (0.0023-0.0043)
Exhaust valve
0.06-0.11 mm (0.0023-0.0043)
Oil system
Oil type
Honda 4-stroke or an equivalent (SG, SF)
Recommended oil
SAE 10W-30, 10W-40
Oil capacity
0.82 L (1.7 US pt., 1.4 Imp. pt.)
Ignition system
Ignition timing
25 ° B.T.D.C (Fixed)
Spark plug
NGK: BR6HS, B6HS
Spark plug gap
0.6-0.7 mm (0.024-0.028 in)
Author:Sergei WersAbout: Co-founder and CEO of a multi-brand auto repair shop (engine repair, chassis repair, body repair and painting) for over 15 years. I have been developing internet sites with technical specifications for more than seven years.
The Honda GS65 is a 240 cc single-cylinder air-coolled 4-stroke internal combustion small gasoline engine manufactured by Honda Motor Company since 1975 for general-purpose applications.
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