Honda GV150

Honda GV150The Honda GV150 is a 144 cc (8.8 single-cylinder air-coolled four-stroke internal combustion small gasoline engine with vertical shaft manufactured by Honda Motor Company.

This engine has a side-valve design with camshaft driven by a timing chain. It has a recoil starter, horizontal butterfly type carburetor, flywheel magneto or CDI ignition system.

The cylinder bore is 64.0 mm (2.5 in) and the piston stroke is 45.0 mm (1.8 in). Compression ratio rating is 6.3:1. The Honda GV150 motor produced 3.5 HP (2.6 kW) at 3600 rpm of horsepower and 7.0 Nm (0.71 kg·m, 5.1 ft·lb) at 3500 rpm of torque.

General information

Engine Specifications
ModelGV150 K1
Type4-stroke, side valve, single cylinder
Displacement144 cm 3 (8.8 cu-in)
Max. horsepower3.5 HP (2.6 kW) at 3600 rpm
Max. torque7.0 Nm (0.71 kg·m, 5.1 ft·lb) at 3500
CarburetorHorizontal type butterfly valve
Cooling systemForced-air
Ignition systemTransistorized magneto ignition or CDI
Lubricating systemTrochoid oil pump
Starting systemRecoil starter
Stoping systemIgnition primary circuit ground
Fuel usedUnleaded gasoline (octane number 86 or higher)
Fuel tank capacity1.0 L (1.27 US pt, 1.06 lmp pt)
Fuel consumption421 g/kWh (310 g/HPh, 0.68 lb/HPh)
PTO shaft rotationCounterclockwise (from PTO shaft side)

Cylinder Block and Head

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 block
Compression ratio:6.3:1
Bore x Stroke64 X 45 mm (2.5 x 1.8 in)
Sleeve internal diameter64.00 mm (2.520 in)
Piston skirt outer diameter63.99 mm (2.519 in)
Number of piston rings (compression / oil):2 / 1
Ring side clearanceTop0.01-0.05 mm (0.0004-0.0020 in)
Second/oil0.01-0.05 mm (0.0004-0.0020 in)
Ring end gapTop/second0.20-0.40 mm (0.008-0.016 in)
Oil0.20-0.40 mm (0.008-0.016 in)
Connecting rod small end ID15.005-15.020 mm (0.5907-0.5913 in)
Crankshaft crank pin outer diameter26.980 mm (1.0622 in)
Cylinder Head
Warpage (limit)0.10 mm (0.004 in)
Valve Arrangement:Side valve (L-head)
Stem outer diameter (standard):INTAKE6.955-6.970 mm (0.2738-0.2744 in)
EXHAUST6.910-6.925 mm (0.2720-0.2726 in)
Cam height:INTAKE29.18 mm (1.149 in)
EXHAUST29.18 mm (1.149 in)
Valve spring free length:36.7 mm (1.45 in)


Idle speed1700 ± 150 rpm
Cylinder compression5.0 kg/cm2 at 600 rpm
Valve clearance
Intake valve0.08-0.16 mm (0.003-0.006 in)
Exhaust valve0.16-0.24 mm (0.006-0.009 in)
Main jet#65
Float height6.7-9.7 mm (0.26-0.38 in)
Pilot screw opening2-1/8 turns
Oil system
Oil typeHonda 4-stroke or an equivalent (SG.SF/CC.CD)
Recommended oilSAE 10W-30
Oil capacity0.6 L (1.27 US pt, 1.06 lmp pt)
Ignition system
Ignition timing20 ° B.T.D.C (Fixed)
Spark plug Flywheel magneto type: NGK: BM6A, BMR6A
Spark plug gap Flywheel magneto type: 0.6-0.7 mm (0.024-0.028 in)
CDI: 0.9-1.0 mm (0.035-0.039 in)

Tightening torque specs

Tightening torque specs
Drain screw (20 mm bolt)40-50 Nm; 4.0-5.0 kg·m; 29-36 ft·lb
Drain screw (12 mm bolt)15-25 Nm; 1.5-2.5 kg·m; 11-18 ft·lb
Flywheel (14 mm nut)70-80 Nm; 7.8-8.0 kg·m; 51-58 ft·lb
Ignition coil (6 mm)8-12 Nm; 0.8-1.2 kg·m; 5.8-8.7 ft·lb
Cylinder head (8 mm bolt)24-26 Nm; 2.4-2.6 kg·m; 17-19 ft·lb
Fan cover8-12 Nm; 0.8-1.2 kg·m; 5.8-8.7 ft·lb
Connecting rod lower cap (7 mm bolt)11-13 Nm; 1.1-1.3 kg·m; 8.0-9.4 ft·lb
Oil pan8-12 Nm; 0.8-1.2 kg·m; 5.8-8.7 ft·lb
Side plate8-12 Nm; 0.8-1.2 kg·m; 5.8-8.7 ft·lb
Tappet cover8-12 Nm; 0.8-1.2 kg·m; 5.8-8.7 ft·lb
Air cleaner case7-10 Nm; 0.7-1.0 kg·m; 5.1-7.2 ft·lb
Muffler13-17 Nm; 1.3-1.7 kg·m; 9.4-12 ft·lb
5 mm bolts, nuts4-7 Nm; 0.4-0.7 kg·m; 2.9-5.1 ft·lb
6 mm bolts, nuts8-12 Nm; 0.8-1.2 kg·m; 5.8-8.7 ft·lb
8 mm bolts, nuts20-28 Nm; 2.0-2.8 kg·m; 14.5-20.3 ft·lb
10 mm bolts, nuts35-40 Nm; 3.5-4.0 kg·m; 25-29 ft·lb
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. How do I read the dipstick on my Honda GV150 3.5 horse power gas mower engine. There seems to be no indicator for the full level.

  2. I don’t know if my first message was sent so I am sending a second message. “How to I read the dipstick on my GV150 3.5 Honda mower engine? I cannot see any specific marking at the end of the dipstick to make sure I am putting enough oil in the engine.”

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