Honda G300

Honda G300The Honda G300 is a 272 cc (16.6 cu·in) natural aspirated single-cylinder four-stroke air-cooled internal combustion small gasoline engine with a horizontal shaft, manufactured by Honda Motor Company for general-purpose applications.

A 76.0 mm (2.99 in) cylinder bore and 60.0 mm (2.36 in) piston stroke give the G300 engine a total of 272 cc of displacement. The compression ratio rating is 6.5:1.

The Honda G300 engine produced 7.1 PS (5.2 kW; 7.0 HP) at 3,600 rpm of maximum output power and 15.0 N·m (1.5 kg·m, 11.1 ft·lb) of peak torque.

The Honda G300 features:

  • L-head design
  • Transistorized magneto or contact point breaker (CDI) ignition system
  • Horizontal type carburetor with butterfly valve
  • Centrifugal govervor
  • Splash lubrication system
  • Forced air cooling system
  • Recoil or electric starter

General information

Engine Specifications
Engine model G300
Engine type 4-stroke, L-head, single-cylinder
Displacement 272 cm3, (16.6 cu·in)
Max. horsepower 7.1 PS (5.2 kW; 7.0 HP) at 3,600 rpm
Max. torque Crankshaft PTO: 15.0 N·m (1.5 kg·m, 11.1 ft·lb)
Camshaft PTO: 29.0 N·m (3.0 kg·m, 12.7 ft·lb)
1/2 reduction: 29.0 N·m (3.0 kg·m, 12.7 ft·lb)
1/6 reduction: 88.0 N·m (9.0 kg·m, 65.1 ft·lb)
Cooling system Forced air
Air cleaner Semi-dry type
Dry type
Oil bath type
Lubricating system Splash type
Ignition system Transistorized magneto or contact point breaker (CDI)
Fuel system Horizontal type carburetor with butterfly valve
Fuel consumption 285 g/HPh
Fuel tank capacity 6.0 L (1.59 US. gal. 1.32 Imp. gal.)
Fuel used Unleaded gasoline (octane number 86 or higher)
Starting system Recoil or electric starter
Stoping system Ignition primary circuit ground
Governor Centrifugal govervor
PTO shaft rotation Counterclockwise (from PTO shaft side)
Dimensions (L x W X H)
Dry weight

Cylinder Block and Head

Cylinder block
Compression ratio: 6.5:1
Cylinder bore: 76.0 mm (2.99 in)
Piston stroke: 60.0 mm (2.36 in)
Cylinder internal diameter (standard): 76.000-76.017 mm (2.9921-2.9928 in)
Piston skirt outer diameter (standard): 75.970-76.000 mm (2.9909-2.9921 in)
Number of piston rings (compression / oil): 2/1
Connecting rod small end diameter (standard): 16.005-16.020 mm (0.6301-0.6307 in)
Side clearance (Top): 0.020-0.060 mm (0.0008-0.0024 in)
Side clearance (Second): 0.010-0.050 mm (0.0004-0.002 in)
Side clearance (Oil): 0.010-0.050 mm (0.0004-0.002 in)
Ring end gap (Top): 0.200-0.400 mm (0.0079-0.0157 in)
Ring end gap (Second): 0.200-0.400 mm (0.0079-0.0157 in)
Ring end gap (Oil): 0.200-0.400 mm (0.0079-0.0157 in)
Ring width (Top): 1.970-1.990 mm (0.0776-0.0783 in)
Ring width (Second): 1.970-1.990 mm (0.0776-0.0783 in)
Ring width (Oil): 3.970-3.990 mm (0.1563-0.1571 in)
Crankpin journal diameter: 29.943-29.959 mm (1.1789-1.1795 in)
Cylinder head
Valve arrangement: L-head
Valves: 2
Valve steam diameter (INTAKE): 6.955-6.970 mm (0.2738-0.2744 in)
Valve steam diameter (EXHAUST): 6.910-6.925 mm (0.272-0.2726 in)
Valve spring free length (INTAKE): 42.7 mm (1.6811 in)
Valve spring free length (EXHAUST): 42.7 mm (1.6811 in)
Camshaft lobe height (INTAKE): 38.460-38.720 mm (1.5142-1.5244 in)
Camshaft lobe height (EXHAUST): 38.460-38.720 mm (1.5142-1.5244 in)

Tightening torque

Tightening torque specs
Fuel valve (12 mm) 12-15 Nm; 1.2-1.5 kg·m; 8.7-10.8 ft·lb
Flywheel (16 mm) 110-120 Nm; 11.0-12.0 kg·m; 80-87 ft·lb
Cylinder head 24-26 Nm; 2.4-2.6 kg·m; 17-19 ft·lb
Tappet cover (6 mm) 8-12 Nm; 0.8-1.2 kg·m; 5.8-8.7 ft·lb
Crankcase cover (8 mm) 20-24 Nm; 2.0-2.4 kg·m; 15-17 ft·lb
Connecting rod 12.6-15.4 Nm; 1.26-1.54 kg·m; 9.1-11 ft·lb
Fuel tank (8 mm) 20-28 Nm; 2.0-2.8 kg·m; 15-20 ft·lb
Oil drain plug 15-25 Nm; 1.5-2.5 kg·m; 11-18 ft·lb
Others
5 mm bolts, nuts 4-7 Nm; 0.4-0.7 kg·m; 2.9-5.1 ft·lb
6 mm bolts, nuts 8-12 Nm; 0.8-1.2 kg·m; 5.8-8.7 ft·lb
8 mm bolts, nuts 20-28 Nm; 2.0-2.8 kg·m; 14.5-20.3 ft·lb
10 mm bolts, nuts 35-40 Nm; 3.5-4.0 kg·m; 25-29 ft·lb

Service Data

Idle speed: 1,400±150 rpm
Cylinder compression: 5.3 kg/cm2 (75 psi)
Valve clearance
Intake valve clearance: 0.08-0.16 mm (0.0031-0.0063 in)
Exhaust valve clearance: 0.11-0.19 mm (0.0043-0.0075 in)
Oil system
Lubrication system: Splash
Oil type: Honda 4-stroke “SE”
Recommended oil: SAE 10W-40
Oil capacity: 1.2 L (1.27 US. qt, 1.06 Imp. qt.)
Reduction device oil capacity: 1/2 reduction: 0.3 L (0.32 US. qt, 0.26 Imp. qt.)
1/6 reduction: 0.15 L (0.16 US. qt, 0.13 Imp. qt.)
Fuel system
Type: Horizontal type carburetor with butterfly valve
Main jet: #88
Float height: 8.2 mm (0.3228 in)
Fuel tank capacity 6.0 L (1.59 US. gal. 1.32 Imp. gal.)
Ignition system
Type: Transistorized magneto or contact point breaker (CDI)
Ignition timing: Magneto ignition: 20° B.T.D.C.
The CDI type does not require adjustment
Spark plug: Magneto ignition: NGK B4H, BR4HS
CDI ignition: NGK BP4HS-10, BPR4HS-10
Spark plug gap: Magneto ignition: 0.6-0.7 mm (0.0236-0.0276 in)
CDI ignition: 0.9-0.10 mm (0.0350-0.0390 in)

Applications

Manufacturer or Brand Models
Generators
Honda E2500, EB2800 EB3000

Be the first to comment

Leave a Reply

Your email address will not be published.


*