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
Type4-stroke, OHC, single cylinder
Displacement187 cm 3 (11.4 cu-in)
Max. horsepower6.0 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
CarburetorHorizontal type, butterfly valve
Cooling systemForced-air
Ignition systemTransistorized magneto ignition
Lubricating systemSplash
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.)
Fuel consumption230 g/HPh
PTO shaft rotationCounterclockwise (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 Stroke69 mm X 50 mm (2.71 x 1.97 in)
Sleeve internal diameter69.00 mm (2.7165 in)
Piston skirt outer diameter68.985 mm (2.7159 in)
Number of piston rings (compression / oil):2 / 1
Ring side clearanceTop0.035-0.065 mm (0.0013-0.0026 in)
Second0.015-0.049 mm (0.0006-0.0019 in)
Ring end gapTop0.20-0.35 mm (0.008-0.014 in)
Second0.30-0.45 mm (0.012-0.018 in)
Oil0.15-0.35 mm (0.006-0.014 in)
Ring widthTop/second1.5 mm (0.06 in)
Oil2.5 mm (0.10 in)
Connecting rod small end ID13.005 mm (0.512 in)
Connecting rod big end ID30.02 mm (1.1819 in)
Crankpin outer diameter29.980 mm (1.1803 in)
Main journal outer diameterPTO side27.993 mm (1.1021 in)
Flywheel side25.393 mm (0.9997 in)
Cylinder Head
Warpage (limit)0.10 mm (0.004 in)
Valve Arrangement:OHC
Stem outer diameter (standard):INTAKE5.480 mm (0.216 in)
EXHAUST5.44 mm (0.214 in)
Guide internal diameterINTAKE / EXHAUST5.5 mm (0.2165 in)
Spring free length34.0 mm (1.34 in)

Tightening torque specs

Tightening torque specs
Air cleaner case bolt10 Nm; 1.0 kg·m; 7 ft·lb
Crankcase cover bolt12 Nm; 1.2 kg·m; 8.6 ft·lb
Connecting rod bolt12 Nm; 1.2 kg·m; 8.6 ft·lb
Valve adjusting lock nut8 Nm; 0.8 kg·m; 5.8 ft·lb
Cylinder head cover bolt12 Nm; 1.2 kg·m; 8.6 ft·lb
Oil drain plug bolt24 Nm; 2.4 kg·m; 17 ft·lb
Flywheel nut52 Nm; 5.3 kg·m; 38 ft·lb
Governor arm nut10 Nm; 1.0 kg·m; 7 ft·lb
Muffler bolt12 Nm; 1.2 kg·m; 8.6 ft·lb
Recoil starter nut8.5 Nm; 0.85 kg·m; 6.1 ft·lb
Fan cover stud bolt12 Nm; 1.2 kg·m; 8.6 ft·lb
Fuel tank bolt, nut10 Nm; 1.0 kg·m; 7 ft·lb
Spark plug20 Nm; 2.0 kg·m; 14 ft·lb
5 mm bolts, nuts5.5 Nm; 0.55 kg·m; 4.0 ft·lb
6 mm bolts, nuts10 Nm; 1.0 kg·m; 7 ft·lb
8 mm bolts, nuts24 Nm; 2.4 kg·m; 17 ft·lb
10 mm bolts, nuts37 Nm; 3.7 kg·m; 27 ft·lb
12 mm bolts, nuts55 Nm; 5.5 kg·m; 39.5 ft·lb

Service Information

Maximum speed3,850 ± 150 rpm
Idle speed1,400 ± 150 rpm
Cylinder compression5.0 kg/cm2 (71 psi) at 600 rpm
Valve clearance
Intake valve0.15 ± 0.04 (0.006 ± 0.002)
Exhaust valve0.20 ± 0.04 (0.008 ± 0.002)
Oil system
Oil typeHonda 4-stroke or an equivalent (SE or SF)
Recommended oilSAE 10W-30
Oil capacity0.58 l (0.61 US. qt, 0.55 Imp. qt.)
Ignition system
Ignition timing20° B.T.D.C.
Spark plugNGK: BPR6ES
Spark plug gap0.7-0.8 mm (0.028-0.031 in)
Spark plug tightening torque20 Nm; 2.0 kg·m; 14 ft·lb
Primary ignition coil resistance1.0-1.2 kΩ
Secondary ignition coil resistance10.6-12.8 kΩ
Ignition coil air gap0.2-0.6 mm (0.008-0.024 in)
Main jet#68
Float height9.2 mm (0.36 in)
Pilot screw opening1-3/4 turns out
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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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.


  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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