Honda GC190

Honda GC190The Honda GC190 is a small (187 cc) single-cylinder air-cooled 4-stroke internal combustion gasoline engine with horizontal shaft, manufactured by Honda Motor Company for general-purpose applications.

This engine has a single-cylinder, compact combustion chamber, tough resin overhead cam for durability and quietness and uniblock construction reduce fuel consumption. The Honda GC190 engine has horizontal type carburetor, recoil starter, and transistorized magneto ignition.

A 69 mm (2.71 in) cylinder bore and 50 mm (1.97 in) piston stroke give the engine a total of 187 cc (11.4 cu-in) of displacement. The compression ratio is 8.5:1. It produces 4.4 kW (6.0 HP) at 3,600 rpm and 12.1 N·m (1.23 kg·m, 8.9 ft·lb) of torque at 2,500 rpm.

General information

Engine Specifications
Model GC190
Type 4-stroke, OHC, single cylinder
Displacement 187 cm 3 (11.4 cu-in)
Max. horsepower 6.0 HP (4.4 kW) at 3,600 rpm
Max. torque (crank PTO) 12.1 N·m (1.23 kg·m, 8.9 ft·lb) at 2,500 rpm
Carburetor Horizontal type, butterfly valve
Cooling system Forced-air
Ignition system Transistorized magneto ignition
Lubricating system Splash
Starting system Recoil starter
Stoping system Ignition primary circuit ground
Fuel used Unleaded gasoline (octane number 86 or higher)
Fuel tank capacity 2.0 l (0.53 US. Gal, 0.44 Imp. Gal.)
Fuel consumption 230 g/HPh
PTO shaft rotation Counterclockwise (from PTO shaft side)

Dimensions and Weight

Length, mm (in) 345 (13.6) 355 (14.0) 345 (13.6)
Width, mm (in) 369 (14.5)
Height, mm (in) 331 (13.0)
Dry weight, kg (lb) 13.2 (29.1)
weight, kg (lb)
15.2 (33.51)

Cylinder Block and Head

Cylinder block
Compression ratio: 8.5:1
Bore x Stroke 69 mm X 50 mm (2.71 x 1.97 in)
Sleeve internal diameter 69.00 mm (2.7165 in)
Piston skirt outer diameter 68.985 mm (2.7159 in)
Number of piston rings (compression / oil): 2 / 1
Ring side clearance Top 0.035-0.065 mm (0.0013-0.0026 in)
Second 0.015-0.049 mm (0.0006-0.0019 in)
Ring end gap Top 0.20-0.35 mm (0.008-0.014 in)
Second 0.30-0.45 mm (0.012-0.018 in)
Oil 0.15-0.35 mm (0.006-0.014 in)
Ring width Top/second 1.5 mm (0.06 in)
Oil 2.5 mm (0.10 in)
Connecting rod small end ID 13.005 mm (0.512 in)
Connecting rod big end ID 30.02 mm (1.1819 in)
Crankpin outer diameter 29.980 mm (1.1803 in)
Main journal outer diameter PTO side 27.993 mm (1.1021 in)
Flywheel side 25.393 mm (0.9997 in)
Cylinder Head
Warpage (limit) 0.10 mm (0.004 in)
Valve Arrangement: OHC
Valves: 2
Stem outer diameter (standard): INTAKE 5.480 mm (0.216 in)
EXHAUST 5.44 mm (0.214 in)
Guide internal diameter INTAKE / EXHAUST 5.5 mm (0.2165 in)
Spring free length 34.0 mm (1.34 in)

Tightening torque specs

Tightening torque specs
Air cleaner case bolt 10 Nm; 1.0 kg·m; 7 ft·lb
Crankcase cover bolt 12 Nm; 1.2 kg·m; 8.6 ft·lb
Connecting rod bolt 12 Nm; 1.2 kg·m; 8.6 ft·lb
Valve adjusting lock nut 8 Nm; 0.8 kg·m; 5.8 ft·lb
Cylinder head cover bolt 12 Nm; 1.2 kg·m; 8.6 ft·lb
Oil drain plug bolt 24 Nm; 2.4 kg·m; 17 ft·lb
Flywheel nut 52 Nm; 5.3 kg·m; 38 ft·lb
Governor arm nut 10 Nm; 1.0 kg·m; 7 ft·lb
Muffler bolt 12 Nm; 1.2 kg·m; 8.6 ft·lb
Recoil starter nut 8.5 Nm; 0.85 kg·m; 6.1 ft·lb
Fan cover stud bolt 12 Nm; 1.2 kg·m; 8.6 ft·lb
Fuel tank bolt, nut 10 Nm; 1.0 kg·m; 7 ft·lb
Spark plug 20 Nm; 2.0 kg·m; 14 ft·lb
5 mm bolts, nuts 5.5 Nm; 0.55 kg·m; 4.0 ft·lb
6 mm bolts, nuts 10 Nm; 1.0 kg·m; 7 ft·lb
8 mm bolts, nuts 24 Nm; 2.4 kg·m; 17 ft·lb
10 mm bolts, nuts 37 Nm; 3.7 kg·m; 27 ft·lb
12 mm bolts, nuts 55 Nm; 5.5 kg·m; 39.5 ft·lb

Service Information

Maximum speed 3,850 ± 150 rpm
Idle speed 1,400 ± 150 rpm
Cylinder compression 5.0 kg/cm2 (71 psi) at 600 rpm
Valve clearance
Intake valve 0.15 ± 0.04 (0.006 ± 0.002)
Exhaust valve 0.20 ± 0.04 (0.008 ± 0.002)
Oil system
Oil type Honda 4-stroke or an equivalent (SE or SF)
Recommended oil SAE 10W-30
Oil capacity 0.58 l (0.61 US. qt, 0.55 Imp. qt.)
Ignition system
Ignition timing 20° B.T.D.C.
Spark plug NGK: BPR6ES
Spark plug gap 0.7-0.8 mm (0.028-0.031 in)
Spark plug tightening torque 20 Nm; 2.0 kg·m; 14 ft·lb
Primary ignition coil resistance 1.0-1.2 kΩ
Secondary ignition coil resistance 10.6-12.8 kΩ
Ignition coil air gap 0.2-0.6 mm (0.008-0.024 in)
Main jet #68
Float height 9.2 mm (0.36 in)
Pilot screw opening 1-3/4 turns out
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  1. My GC 190 is leaking oil- a lot of oil. It is on my log splitter and it’s very annoying.
    I thought all Honda motors were quality engines. How do I fix this?

    • the oil leaks out of the crankcase through the governor shaft hole because Honda didnt machine the engine for a governor shaft seal, cheap shot from them! there is no fix for this! I actually bought the $3 seal and couldn”t install becauuse the hole isnt machined for it!

    • Honda engines are one of the best. Just not this model. This is pretty much their cheap throw away motor

  2. Hola adquirí un motor honda gc190..En mi trabajo siempre e trabajado con este motor me a salido muy bueno pero este nuevo que adquiri.viene muy sencillo. Lo que e checando de este motor no trae valeros en el eje del cigueñal no trae metales de viela y los viejito que tenemos traen todo eso e incluso la viela viene de otro material más duro quiero saber si ay alguna diferencia entre los dos en tiempo y resistencia ya que los viejito y el nuevo son el mismo número de parte

  3. Disculpe la pregunta anterior fue un poco mal redactada… Solo quiero saber la diferencia entre mi motor viejito y el motor nuevo que adquirí honda gc 190 los dos son iguales en número solo la diferencia que uno es de valero en el eje del cigueñal y metales de viela y el nuevo que acabo de adquirir no trae valeros ni metales de viela quiero saber si los dos cuentan con la misma resistencia ya que el caballaje es el mismo

  4. This isn’t a real Honda engine. Rather, a Chinese made generic engine with Honda decals. I have one in my PW and, it’s not all that great of an engine.

  5. I have a Honda GC190 n a power washer. I have a horrible time starting the engine. Occasionaly I pull the pull cord once and it starts right up. Usually it is the opposite. I can barley pull the cord at all am and cant start it, period. The machine is not old, has only been used maybe 6 times. Ideas? Really ticked off.

  6. I am replacing my rod assembly on a Honda GC190 engine. My problem is, when I tighten the rod assembly bolts to the crank shaft, the crank shaft will not turn. Either by hand or pull cord. When I loosen the bolts just a tad, it turn freely. What am I doing wrong? How do I tighten those bolts?

  7. Runs great, starts easy, no power, cleaned filter, drained fuel bowl, cleaned muffler, adjusted idle speed. No difference. Engine not old.

  8. Please, please…where is the fuel filter located on the GS190 6 HP Honda 4 cycle?? The owners manual says nothing of the fuel filter or “how to’ replace it.
    Thanks, SD

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