Honda iGX440

Honda iGX440The Honda iGX440 is a 0.44 l (438 cc, 26.7 cu·in) single-cylinder air-coolled 4-stroke internal combustion small gasoline (petrol) engine with horizontal shaft, manufactured by Honda Motor for general-purpose applications, such as pressure washers, generators, forestry equipment, construction and industrial equipment, agricultural equipment, water pumps.

The iGX440 engine has STR (Self Tuning Regulator) governor, digital C.D.I.(Capacitor Discharge Ignition), horizontal type butterfly valve carburetor and recoil or electric starter motor. The iGX440 cylinder bore is 88.0 mm (3.46 in) and piston stroke is 72.1 mm (2.84 in), compression ratio rating is 8.1:1.

The Honda iGX440 produces 12.7 HP (9.5 kW; 12.9 PS) at 3,600 rpm net power and 29.8 N·m (3.0 kgf·m, 22.0 lb·ft) at 2500 rpm of net torque.

General information

Engine Specifications
Model iGX440
Type 4-stroke, OVH, single cylinder, inclined by 25°
Displacement 438 cm 3 (26.7 cu·in)
Max. horsepower 12.7 HP (9.5 kW; 12.9 PS) at 3600 rpm
Max. torque 29.8 N·m (3.0 kgf·m, 22.0 lb·ft) at 2500 rpm
Carburetor Horizontal type, butterfly valve
Cooling system Forced-air
Ignition system Digital C.D.I.(Capacitor Discharge Ignition) with variable ignition timing
Lubricating system Forced splash
Starting system Recoil and Starter motor
Stoping system Ignition exciter coil circuit open
Fuel used Unleaded gasoline (octane number 86 or higher)
Fuel consumption 3.5 Liters (0.92 US gal, 0.77 Imp gal) / h
PTO shaft rotation Counterclockwise (from PTO shaft side)

Cylinder Block and Head

The Honda iGX440 has cast iron cylinder sleeve, ball bearing supported crankshaft, improved piston design, heavy-duty balancer shaft. The piston has two compression rings and one oil ring. Precision camshaft design offers precise valve timing and optimal valve overlap for better fuel efficiency. The engine has integrated ECU (electronic control unit) with a self-tuning regulator (STR) governor system.

Cylinder block
Compression ratio: 8.1:1
Bore x Stroke 88 X 72.1 mm (3.5 x 2.84 in)
Sleeve internal diameter 88.000-88.017 mm (3.4646-3.4652 in)
Piston skirt outer diameter 87.985-87.965 mm (3.4640-3.4632 mm)
Number of piston rings (compression / oil): 2 / 1
Ring side clearance Top 0.030-0.050 mm (0.0012-0.0022 in)
Second 0.030-0.050 mm (0.0012-0.0022 in)
Ring end gap Top 0.20-0.35 mm (0.008-0.014 in)
Second 0.35-0.50 mm (0.014-0.020 in)
Ring width Top 1.490-1.475 mm (0.0587-0.0581 in)
Second 1.490-1.475 mm (0.0587-0.0581 in)
Piston pin outer diameter 20.994-21.000 mm (0.8265-0.8268 in)
Connecting rod small end inner diameter 20.994-21.000 mm (0.8265-0.8268 in)
Connecting rod big end inner diameter 40.039-40.025 mm (1.5763-1.5758 in)
Crankpin outer diameter 39.975-39.985 mm (1.5738-1.7542 in)
Cylinder Head
Warpage (limit) 0.10 mm (0.004 in)
Valve Arrangement: OHV
Valves: 2
Stem outer diameter (standard): INTAKE 5.478-5.490 mm (0.2157-0.2161 in)
EXHAUST 5.435-5.450 mm (0.2140-0.2146 in)
Valve spring free length: 46.3 mm (1.82 in)
Cam height: INTAKE 30.736-31.136 mm (1.2101-1.2258 in)
EXHAUST 30.145-30.545 mm (1.1868-1.2026 in)
Camshaft outer diameter: 21.470-21.500 mm (0.8453-0.8465 in)

Tightening torque specs

Tightening torque specs
Connecting rod bolt 14 Nm; 1.4 kg·m; 10 ft·lb
Cylinder head bolt 35 Nm; 3.5 kg·m; 25 ft·lb
Flywheel nut 165 Nm; 16.8 kg·m; 122 ft·lb
Bearing holder bolt 26 Nm; 2.6 kg·m; 19 ft·lb
Crankcase cover bolt 24 Nm; 2.4 kg·m; 17 ft·lb
Cam pulley bolt 16 Nm; 1.6 kg·m; 12 ft·lb
Rocker arm shaft bolt 23 Nm; 2.3 kg·m; 17 ft·lb
Starter motor nut 8.8 Nm; 0.9 kg·m; 6.5 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

Maintenance data

Maximum speed 3,600 ± 150 rpm
Idle speed 1,400 ± 150 rpm
Cylinder compression 4-7 kg/cm2 (57-100 psi, 0.39-0.68 MPa) at 600 rpm
Valve clearance
Intake valve 0.15 ± 0.02 (0.006 ± 0.001)
Exhaust valve 0.20 ± 0.02 (0.008 ± 0.001)
Oil system
Oil type Honda 4-stroke or an equivalent (SE or later)
Recommended oil SAE 10W-30
Oil capacity 1.1 L (1.16 US gal, 0.97 lmp qt)
Main jet #112
Float height 13.2 mm (0.52 in)
Pilot screw opening 1-5/8 turns out
Ignition system
Ignition timing B.T.D.C. 10° / 1,400 rpm
Spark plug NGK: BKR7E-E
Spark plug gap 0.7-0.8 mm (0.028-0.031 in)
Author: Sergei Wers
About: 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.

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  1. Hello wondering if u have had any problems with the ecu on this engine ? I brought two new ecu for this motor and they don’t rev 🙁 it’s not the machine as the ecu I had before I brought the two new one worked fine

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