Honda G28

Honda G28 engineThe Honda G28 is a 67 cc (4.09 single-cylinder air-coolled 4-stroke internal combustion small gasoline engine manufactured by Honda Motor Company since 1969 for general-purpose applications.

The G28 has an overhead camshaft and an efficient combustion chamber designs together with a high-performance carburetor. Friction components such as the cylinder sleeve and piston are made of high strength materials. The crankshaft is mounted on ball bearings for reduced friction.

The Honda G28 engine compression ratio rating is 8.3:1, cylinder bore and piston stroke are 49.0 mm (1.93 in) and 35.5 mm (1.40 in), respectively.

The G28 produced 2.0 HP (1.49 kW) at 5000 rpm of continuous rated horsepower and from 2.8 HP (2.08 kW) to 3.0 HP (2.23 kW) at 6000 rpm of maximum horsepower.

General information

Engine Specifications
Model G28
Type 4-stroke, single cylinder
Displacement 67 cm 3 (4.09 cu-in)
Max. horsepower 2.8 HP (2.23 kW) at 6000 rpm
Max. torque
Carburetor Horizontal, butterfly valve
Cooling system Forced-air
Ignition system High voltage ignition
Lubricating system Splash system
Starting system Recoil starter
Stoping system Ground switch
Fuel used Unleaded gasoline (octane number 86 or higher)
Fuel tank capacity 2.6 L
PTO shaft rotation Counterclockwise (from PTO shaft side)

Maintenance data

Oil system
Oil type Honda 4-stroke or an equivalent
Recommended oil SAE 10W-30 or 10W-40
Oil capacity 0.7 l
Ignition system
Spark plug NGK: C-6HB
Spark plug gap 0.6-0.7 mm (0.024-0.028 in)
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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.


    • Check the oil level with the dipstick gauge on the oil filler cup:
      Upper limit-Lower lip of the oil filler opening.
      Lower limit-Ridge on the dipstick gauge.

  1. Hello, I have a Honda G28 motor/generator. I have had trouble getting spare parts for the motor. Possibly due to the age of the unit. Is there a modern day replacement Honda motor that I can use instead of the G28. Thanks.

    • Hi
      I’m having the same trouble
      Alot of the new motors turn anticlockwise on the pto for starters

      Did you receive any replys on replacement engine or even parts?

  2. I need a photo of the top of a g28 engine as I have 1 but the choke and accelerator wire have been removed and hard to find which way they go back on

  3. Hello!

    I need a carburator to a honda G28.
    Is there any chance to find one on the market?


  4. Hi I have a G28 and need a carburettor or replacement plastic bubble on the bottom as it has distorted with the heat from the exhaust. The carb is fine I think there must be a modification but not find the info needed.

    • Hi Nigel, mine has been missing the plastic bubble for years. when i bought it it had a bolt and washer holding the float bowl on instead and has run like that ok since. if you need a pic of the carb let me know

  5. I have a waterpump honda g28 it runs good but no starter.
    Do you have one? I can even sel the engine. I live in the Nederlands.

  6. Hi I’m after a g28 motor for my Honda tiller does any one have one or know where I can get one from …..I’m from Tasmania which is part of Australia

  7. Hey I have an old Honda g28 engine but I can’t understand how I would connect the accelerator to the carburettor

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