Honda GX120T2

The Honda GX120 T2 is a 118 cc (7.2 cu-in) single-cylinder inclined by 25° air-cooled 4-stroke internal combustion small gasoline engine with horizontal shaft manufactured by Honda Motor Company for general-purpose applications, such as commercial lawn and garden equipment, tillers and cultivators, generators, construction and industrial equipment, agricultural equipment and water pumps.

The Honda GX120 T2 engine has an OHV (overhead valve) design; high compression ratio for better fuel efficiency; horizontal type carburetor with butterfly valve; mechanical centrifugal governor; forced splash lubrication system; heavy-duty recoil starter and C.D.I. (Capacitor Discharge Ignition) type magneto ignition. The engine can be equipped with the dual-type, semi-dry type, dual silent type, oil bath type or cyclone-type air cleaner

The cylinder bore is 60.0 mm (2.4 in) and the piston stroke is 42.0 mm (1.7 in), compression ratio rating is 8.5:1. The engine produced 3.5 HP (2.6 kW) at 3,600 rpm of maximum horsepower and 2.9 HP (2.1 kW) at 3,600 rpm of continuous rated power. Maximum torque is 7.3 N·m (0.7 kg·m, 5.4 ft·lb) at 2,500 rpm.

General information

Engine Specifications
ModelGX120 T2 / UT2
Type4-stroke, OHV, single cylinder inclined by 25°
Displacement118 cm 3 (7.2 cu-in)
Max. horsepower3.5 HP (2.6 kW) at 3,600 rpm
Max. torque (crank PTO)7.3 N·m (0.7 kg·m, 5.4 ft·lb) at 2,500 rpm
CarburetorHorizontal type, butterfly valve
Cooling systemForced-air
Ignition systemC.D.I. (Capacitor Discharge Ignition)
Lubricating systemForced splash
Starting systemRecoil starter
Stoping systemIgnition primary circuit ground
Fuel usedUnleaded gasoline (octane number 86 or higher)
Fuel tank capacity2.0 L (0.53 US Gal, 0.44 Imp Gal.)
PTO shaft rotationCounterclockwise (from PTO shaft side)

Cylinder Block and Head

The Honda GX120T2 has cast iron cylinder sleeve, ball bearing supported forged steel crankshaft, improved piston design. 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. Cylinder bore and piston stroke are 60.0 mm (2.4 in) and 42.0 mm (1.7 in), respectively. Compression ratio rating is 8.5:1

Cylinder block
Compression ratio:8.5:1
Bore x Stroke60 X 42 mm (2.4 x 1.7 in)
Sleeve internal diameter60.00 mm (2.36 in)
Piston skirt outer diameter59.985 mm (2.3616 in)
Number of piston rings (compression / oil):2 / 1
Ring side clearanceTop0.035-0.070 mm (0.0014-0.0028 in)
Second0.045-0.080 mm (0.0018-0.0032 in)
Ring end gapTop0.20-0.35 mm (0.0079-0.0138 in)
Second0.35-0.50 mm (0.0138-0.0197 in)
Oil (side rail)0.2-0.7 mm (0.01-0.03 in)
Ring widthTop0.95-0.97 mm (0.0374-0.0382 in)
Second0.94-0.96 mm (0.0370-0.0378 in)
Connecting rod small end ID13.005 mm (0.5120 in)
Connecting rod big end ID26.02 mm (1.024 in)
Piston pin outer diameter13.0 mm (0.51 in)
Crankshaft crank pin outer diameter25.98 mm (1.023 in)
Cylinder Head
Warpage (limit)0.10 mm (0.004 in)
Valve Arrangement:OHV
Stem outer diameter (standard):INTAKE5.468-5.480 mm (0.2153-0.2157 in)
EXHAUST5.425-5.440 mm (0.2136-0.2142 in)
Valve spring free length:30.5 mm (1.20 in)
Camshaft outer diameter:13.984 mm (0.5506 in)
Cam height:INTAKE27.500-27.900 mm (1.0827-1.0984 in)
EXHAUST27.547-27.947 mm (1.0845-1.1003 in)

Tightening torque specs

Tightening torque specs
Connecting rod bolt12 Nm; 1.2 kg·m; 9 ft·lb
Cylinder head bolt24 Nm; 2.4 kg·m; 17 ft·lb
Flywheel nut75 Nm; 7.5 kg·m; 54 ft·lb
Rocker arm pivot adjusting nut10 Nm; 1.0 kg·m; 7 ft·lb
Rocker arm pivot bolt24 Nm; 2.4 kg·m; 17 ft·lb
Crankcase cover bolt12 Nm; 1.2 kg·m; 9 ft·lb
Oil level switch joint nut10 Nm; 1.0 kg·m; 7 ft·lb

Service Information

Maximum speed3,900 ± 100 rpm
Idle speed1,400 ± 150 rpm
Cylinder compression5.0-7.0 kg/cm2 (71-100 psi) at 600 rpm
Valve clearance
Intake valve clearance0.15±0.02 mm (0.006±0.001 in)
Exhaust valve clearance0.20±0.02 mm (0.008±0.001 in)
Oil system
Oil typeHonda 4-stroke or an equivalent (SJ or higher)
Recommended oilSAE 10W-30
Oil capacity0.56 L (0.59 US. qt, 0.49 Imp. qt.)
Main jet BE99A: #60
BE60W, BE61M, BE99B: #62
Float height13.7 mm (0.54 in)
Pilot screw opening BE99A: 2 turns out
BE60W, BE61M, BE99B: 2-3/8 turns out
Ignition system
Ignition timing20° B.T.D.C.
Spark plugNGK: BPR6ES
Spark plug gap0.7-0.8 mm (0.028-0.031 in)
Primary ignition coil resistance0.6-0.9 Ω
Secondary ignition coil resistance5.6-6.9 kΩ
Ignition coil air gap0.4 ± 0.2 (0.016 ± 0.008)
ATTENTION! Dear visitors, this site is not a trading platform, an official dealer or a spare parts supplier, so we do not have any price lists or spare parts catalogs. We are an information portal and provide the technical specifications of gasoline and diesel engines.

We try to use verified sources and official documentation, however, differences between sources or errors in entering information may occur. We do not provide advice on technical issues related to the engines operation or repair. We do not recommend using provided information for engines repairing engines or spare parts ordering, use only official service manuals and spare-parts catalogs.

Be the first to comment

Leave a Reply

Your email address will not be published.