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| Home / Small Engines / Honda Engines / Honda GX340 |
Honda GX340 Maintenance
| Engine Model: Honda GX340 |
| Engine Type: 4-cycle OHV 1-cylinder gasoline engine |
| Total Displacement: 20.6 cu.in (337 cc) |
| Rated Engine Power: 11 Hp (8.2 kW) at 3600 rpm |
| Carburetor Type: Horizontal, butterfly valve |
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| Service Data |
Cylinder Bore Inside Diameter (Maximum), in (mm) .............. 3.235 (82.170)
Cylinder Compression, psi (kPa) .............. 85-121 (600-850)
Cylinder Head (Max Out of Flatness), in (mm) .............. 0.004 (0.10)
Intake Valve Clearance, in (mm) .............. 0.006 (0.15)
Exhaust Valve Clearance, in (mm) .............. 0.008 (0.20)
| Engine Oil and Filter |
Engine Oil Type (Summer) .............. SAE 10W-30
Engine Oil Type (Winter) .............. SAE 5W-30
API Service Classifications .............. CC, CD, SG, SF
Oil Capacity, qts (L) .............. 1.16 (1.10)
Air Filter Element Part Number .............. 17210-ZE3-010
| Carburetor Adjustment |
Main Jet (Externally/Internally Vented Bowl) .............. #98 / #108
Idle Fuel (Externally/Internally Vented Bowl) .............. 2-1/2 turns out / 3 turns out
Float Height, in (mm) .............. 0.52 (13.2)
Low Idle Speed, rpm .............. 1400±150
High Idle Speed, rpm .............. 3850±150
| Ignition System |
Spark Plug Type .............. NGK BPR6ES or Denso W20EPR-U
Spark Plug Gap, in (mm) .............. 0.028-0.032 (0.70-0.80)
Module Air Gap, in (mm) .............. 0.008-0.024 (0.20-0.60)
Ignition Timing, deg .............. 25 BTDC
Spark Plug Torque, Nm (ft-lbs) .............. 20 (14)
| Service Intervals |
Check Engine Oil Level .............. Every 10 hours
Clean Air Filter Element .............. Every 50 hours
Change Engine Oil .............. Every 100 hours
Check and Adjust Spark Plug .............. Every 100 hours
Clean Fuel Strainer .............. Every 300 hours
Check and Adjust Idle Speed .............. Every 300 hours
Check Carburetor Adjustment .............. Every 300 hours
Replace Spark Plug .............. Every 300 hours
Replace Air Filter Element .............. Every 300 hours
Check and Adjust Valve Clearance .............. Every 300 hours
Clean Combustion Chamber .............. Every 300 hours
Clean Fuel Line .............. Every 300 hours
| Tightening Torques |
Crankcase Cover (M8x1.25) .............. 24 Nm (18 ft-lb)
Cylinder Head Cover Bolt (M10x1.25) .............. 35 Nm (25 ft-lb)
Rocker Arm Pivot Bolt (M8x1.25) .............. 24 Nm (18 ft-lb)
Oil Drain Plug Bolt (M12x1.5) .............. 23 Nm (17 ft-lb)
Connecting Rod Bolt (M8x1.25) .............. 14 Nm (10 ft-lb)
Flywheel Nut (M16x1.5) .............. 115 Nm (83 ft-lb)
Air Cleaner Wing Nut (M6x1.0) .............. 10 Nm (7 ft-lb)
Muffler Bolt (M8x1.25) .............. 24 Nm (17 ft-lb)
Oil Level Switch Bolt (M10x1.25) .............. 10 Nm (7 ft-lb)
Fuel Strainer Cup (M24x1.0) .............. 3.9 Nm (2.9 ft-lb)
Spark Plug (M14x1.25) .............. 20 Nm (14 ft-lb)
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