Honda GX340 R2/RT2/T2/U2/UT2

Honda GX340 R2/RT2/T2/U2/UT2The Honda GX340 R2/RT2/T2/U2/UT2 is a 389 cc, (23.74 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.

It has an 88.0 mm (3.46 in) cylinder bore and 64.0 mm (2.52 in) piston stroke. The compression ratio rating is 8.2:1.

This engine produced 10.9 PS (8.0 kW; 10.7 HP) at 3,600 rpm of net power or 8.6 PS (6.3 kW; 8.4 HP) at 3,600 rpm of continuous rated power and 26.4 N·m (2.7 kg·m, 19.5 ft·lb) at rpm of torque.

The Honda GX340 R2/RT2/T2/U2/UT2 features:

  • OHV design
  • C.D.I.(Capacitor Discharge Ignition) type magneto ignition system
  • Horizontal type carburetor with butterfly valve
  • Mechanical centrifugal governor
  • Forced lubrication lubrication system
  • Forced air cooling system
  • Recoil, recoil and starter motor

General information

Engine Specifications
Engine model GX340 R2/RT2/T2/U2/UT2
Engine type 4-stroke, OHV, single-cylinder
Displacement 389 cm3, (23.74 cu·in)
Max. horsepower 10.9 PS (8.0 kW; 10.7 HP) at 3,600 rpm
Max. torque 26.4 N·m (2.7 kg·m, 19.5 ft·lb) at rpm
Cooling system Forced air
Air cleaner Dual element type,
Cyclone type,
Oil bath type,
Low profile type
Lubricating system Forced lubrication
Ignition system C.D.I.(Capacitor Discharge Ignition) type magneto ignition
Fuel system Horizontal type carburetor with butterfly valve
Fuel consumption 3.1 Liters (0.82 US gal, 0.68 Imp gal)/h
Fuel tank capacity 6.1 L (1.61 US. gal. 1.34 Imp. gal.)
Fuel used Unleaded gasoline (octane number 86 or higher)
Starting system Recoil, recoil and starter motor
Stoping system Ignition exciter coil circuit open
Governor Mechanical centrifugal governor
PTO shaft rotation Counterclockwise (from PTO shaft side)
Dimensions (L x W X H) 407 x 485 x 449 mm (16 x 19.1 x 17.7 in)
Dry weight 31.5 kg (69.4 lbs)

Cylinder Block and Head

Cylinder block
Compression ratio: 8.2:1
Cylinder bore: 88.0 mm (3.46 in)
Piston stroke: 64.0 mm (2.52 in)
Cylinder internal diameter (standard): 88.000-88.017 mm (3.4646-3.4652 in)
Piston skirt outer diameter (standard): 87.965-87.985 mm (3.4632-3.464 in)
Number of piston rings (compression / oil): 2/1
Connecting rod big end diameter (standard): 36.025-36.039 mm (1.4183-1.4189 in)
Connecting rod small end diameter (standard): 19.994-20.000 mm (0.7872-0.7874 in)
Piston pin diameter: 17.994-18.000 mm (0.7084-0.7087 in)
Side clearance (Top): 0.030-0.060 mm (0.0012-0.0024 in)
Side clearance (Second): 0.030-0.060 mm (0.0012-0.0024 in)
Ring end gap (Top): 0.200-0.350 mm (0.0079-0.0138 in)
Ring end gap (Second): 0.350-0.500 mm (0.0138-0.0197 in)
Ring end gap (Oil): 0.200-0.700 mm (0.0079-0.0276 in)
Ring width (Top): 1.160-1.175 mm (0.0457-0.0463 in)
Ring width (Second): 1.160-1.175 mm (0.0457-0.0463 in)
Crankpin journal diameter: 35.975-35.985 mm (1.4163-1.4167 in)
Crankshaft center distance: 32 mm (1.26 in)
Cylinder head
Valve arrangement: OHV, gear driven
Valves: 2
Valve steam diameter (INTAKE): 6.575-6.590 mm (0.2589-0.2594 in)
Valve steam diameter (EXHAUST): 6.535-6.550 mm (0.2573-0.2579 in)
Valve spring free length (INTAKE): 39.0 mm (1.5354 in)
Valve spring free length (EXHAUST): 39.0 mm (1.5354 in)
Camshaft lobe height (INTAKE): 31.945-32.145 mm (1.2577-1.2655 in)
Camshaft lobe height (EXHAUST): 31.666-31.866 mm (1.2467-1.2546 in)
Camshaft journal diameter : 15.966-15.984 mm (0.6286-0.6293 in)

Tightening torque specs

Tightening torque specs
Connecting rod bolt (M8x1.25 Special) 14 Nm; 1.4 kg·m; 10 ft·lb
Cylinder head bolt (M10x1.25) 35 Nm; 3.5 kg·m; 25 ft·lb
Flywheel nut (M16x1.5 Special) 115 Nm; 11.5 kg·m; 83 ft·lb
Rocker arm pivot lock nut (M6x0.5) 10 Nm; 1.0 kg·m; 7 ft·lb
Rocker arm pivot bolt (M8x1.25 Special) 24 Nm; 2.4 kg·m; 17 ft·lb
Crankcase cover bolt (M8x1.25) 24 Nm; 2.4 kg·m; 17 ft·lb
Oil level switch joint nut (M10x1.25) 10 Nm; 1.0 kg·m; 7 ft·lb
Fuel filter joint nut (M10x1.25) 2 Nm; 0.2 kg·m; 1.4 ft·lb
Muffler mounting nut (M8x1.25) 24 Nm; 2.4 kg·m; 17 ft·lb
Air cleaner wing nut (M6x1.0) 9 Nm; 0.9 kg·m; 6.5 ft·lb
Oil drain bolt (M12x1.5) 23 Nm; 2.3 kg·m; 17 ft·lb
Fuel tank bolt (M8x1.25) 24 Nm; 2.4 kg·m; 17 ft·lb
Air cleaner mounting nut (M6x1.0) 10 Nm; 1.0 kg·m; 7 ft·lb
Fuel strainer cup (M24x1.0) 4 Nm; 0.4 kg·m; 2.9 ft·lb
Standard torque values
Bolt, nut (5 mm) 5.5 Nm; 0.55 kg·m; 4.0 ft·lb
Bolt, nut (6 mm) 10 Nm; 1.0 kg·m; 7 ft·lb
Bolt, nut (8 mm) 24 Nm; 2.4 kg·m; 17 ft·lb
Bolt, nut (10 mm) 37.5 Nm; 3.75 kg·m; 27 ft·lb
Bolt, nut (12 mm) 55 Nm; 5.5 kg·m; 40 ft·lb

Service Data

Engine
Maximum speed: 3,450-3,800 rpm rpm
Idle speed: 1,250-1,550 rpm
Cylinder compression: 0.59-0.83 MPa (6.0-8.5 kgf/cm2, 85-121 psi) /600 rpm
Valve clearance
Intake valve clearance: 0.13-0.17 mm (0.0051-0.0067 in)
Exhaust valve clearance: 0.18-0.22 mm (0.0071-0.0087 in)
Oil system
Lubrication system: Forced lubrication
Oil type: Honda 4-stroke or an equivalent (SE or later)
Recommended oil: SAE 10W-30
Oil capacity: 1.1 L (1.16 US. qt, 0.97 Imp. qt.)
Fuel system
Type: Horizontal type carburetor with butterfly valve
Main jet: #98
Float height: 13.2 mm (0.5197 in)
Pilot screw opening: 1 – 3/4 turns out
Ignition system
Type: C.D.I.(Capacitor Discharge Ignition) type magneto ignition
Ignition timing: 10° B.T.D.C. /1,400 rpm
Spark plug: NGK: BPR6ES DENSO: W20EPR-U
Spark plug gap: 0.7-0.8 mm (0.0276-0.0315 in)
Spark plug torque: 18 N·m (1.8 kg·m, 13.3 ft·lb)
Ignition coil air gap 0.2-0.6 mm (0.0079-0.0236 in)

Be the first to comment

Leave a Reply

Your email address will not be published.


*