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
Model GV150 K1
Type 4-stroke, side valve, single cylinder
Displacement 144 cm 3 (8.8 cu-in)
Max. horsepower 3.5 HP (2.6 kW) at 3600 rpm
Max. torque 7.0 Nm (0.71 kg·m, 5.1 ft·lb) at 3500
Carburetor Horizontal type butterfly valve
Cooling system Forced-air
Ignition system Transistorized magneto ignition or CDI
Lubricating system Trochoid oil pump
Starting system Recoil starter
Stoping system Ignition primary circuit ground
Fuel used Unleaded gasoline (octane number 86 or higher)
Fuel tank capacity 1.0 L (1.27 US pt, 1.06 lmp pt)
Fuel consumption 421 g/kWh (310 g/HPh, 0.68 lb/HPh)
PTO shaft rotation Counterclockwise (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 Stroke 64 X 45 mm (2.5 x 1.8 in)
Sleeve internal diameter 64.00 mm (2.520 in)
Piston skirt outer diameter 63.99 mm (2.519 in)
Number of piston rings (compression / oil): 2 / 1
Ring side clearance Top 0.01-0.05 mm (0.0004-0.0020 in)
Second/oil 0.01-0.05 mm (0.0004-0.0020 in)
Ring end gap Top/second 0.20-0.40 mm (0.008-0.016 in)
Oil 0.20-0.40 mm (0.008-0.016 in)
Connecting rod small end ID 15.005-15.020 mm (0.5907-0.5913 in)
Crankshaft crank pin outer diameter 26.980 mm (1.0622 in)
Cylinder Head
Warpage (limit) 0.10 mm (0.004 in)
Valve Arrangement: Side valve (L-head)
Valves: 2
Stem outer diameter (standard): INTAKE 6.955-6.970 mm (0.2738-0.2744 in)
EXHAUST 6.910-6.925 mm (0.2720-0.2726 in)
Cam height: INTAKE 29.18 mm (1.149 in)
EXHAUST 29.18 mm (1.149 in)
Valve spring free length: 36.7 mm (1.45 in)


Idle speed 1700 ± 150 rpm
Cylinder compression 5.0 kg/cm2 at 600 rpm
Valve clearance
Intake valve 0.08-0.16 mm (0.003-0.006 in)
Exhaust valve 0.16-0.24 mm (0.006-0.009 in)
Main jet #65
Float height 6.7-9.7 mm (0.26-0.38 in)
Pilot screw opening 2-1/8 turns
Oil system
Oil type Honda 4-stroke or an equivalent (SG.SF/CC.CD)
Recommended oil SAE 10W-30
Oil capacity 0.6 L (1.27 US pt, 1.06 lmp pt)
Ignition system
Ignition timing 20 ° 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 cover 8-12 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 pan 8-12 Nm; 0.8-1.2 kg·m; 5.8-8.7 ft·lb
Side plate 8-12 Nm; 0.8-1.2 kg·m; 5.8-8.7 ft·lb
Tappet cover 8-12 Nm; 0.8-1.2 kg·m; 5.8-8.7 ft·lb
Air cleaner case 7-10 Nm; 0.7-1.0 kg·m; 5.1-7.2 ft·lb
Muffler 13-17 Nm; 1.3-1.7 kg·m; 9.4-12 ft·lb
5 mm bolts, nuts 4-7 Nm; 0.4-0.7 kg·m; 2.9-5.1 ft·lb
6 mm bolts, nuts 8-12 Nm; 0.8-1.2 kg·m; 5.8-8.7 ft·lb
8 mm bolts, nuts 20-28 Nm; 2.0-2.8 kg·m; 14.5-20.3 ft·lb
10 mm bolts, nuts 35-40 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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