Facts About Generators
GeneratorsDirectoryCompareRepairEnginesControllersPartsManufacturersGuides
Search models or part #
Home›Engines›Cummins/Onan 6 - 3.25 inch (82.55 mm) x 2.875 inch (73 mm)

Cummins/Onan 6 - 3.25 inch (82.55 mm) x 2.875 inch (73 mm) Engine

The Cummins/Onan 6 - 3.25 inch (82.55 mm) x 2.875 inch (73 mm) is a 0.78 L 2-cylinder engine rated at 600 rpm, producing up to 13.4 kW. It powers generator sets from Cummins/Onan, including the GSP-1. It holds 1.66 L (0.4 gal) of oil.

Also known as: Onan/Cummins 6 - 3.25 inch (82.55 mm) x 2.875 inch (73 mm)

0.782 L
Displacement
2
Cylinders
600 rpm
Rated speed
13 kW
Gross power
On this pageSpecsGenerator setsMaintenanceFAQ

Engine specifications

Oil capacity1.66 L
Displacement0.782 L
Cylinders2
Rated speed600 rpm
Gross power13 kW

Generator sets powered by this engine

1
Cummins/Onan GSP-1

How to read your Cummins/Onan engine serial & model number →

Common problems

15
  • Engine will not start when cranked
    Cause: Air in fuel system
    Fix: Bleed the fuel system.
  • Excessive oil consumption, light blue smoky exhaust
    Cause: Poor compression, usually due to worn piston, rings, or cylinder
    Fix: Refinish or replace cylinder. Replace piston and rings
  • Excessive oil consumption - light blue smoky exhaust
    Cause: Poor compression. Usually due to worn piston, rings, or cylinder
    Fix: Refinish cylinder. Install oversize piston and rings.
  • Power drops under heavy load
    Cause: Engine lacks power
    Fix: See remedies for engine missing under heavy load
  • Low oil pressure
    Cause: Defective oil pressure gauge
    Fix: Replace.
  • Engine misfires at light load
    Cause: Faulty injection
    Fix: Dirty fuel is main cause. Use only recommended fuels.
  • Engine cranks slowly or will not crank
    Cause: Defective or discharge battery
    Fix: Replace or recharge battery.
  • Voltage drops under heavy load
    Cause: Engine lacks power
    Fix: See Engine Misfires at Heavy Loads.
  • Engine stops unexpectedly
    Cause: Empty fuel tank
    Fix: Refill fuel tank as often as needed to prevent running out of fuel.
  • Engine misfires at all speeds
    Cause: Fouled spark plug
    Fix: Clean and adjust
  • Engine low on power
    Cause: Oil too light
    Fix: Drain, refill with proper oil
  • Engine backfires at carburetor
    Cause: Lean fuel mixture
    Fix: Clean or adjust carburetor
  • Engine overheating
    Cause: Improper lubrication
    Fix: See Low Oil Pressure.
  • Engine misfires at heavy load
    Cause: Defective spark plug
    Fix: Replace
  • Black smoky exhaust - excessive fuel consumption - possible lack of power under load
    Cause: Generator overloaded. Black smoky exhaust normal condition with overload
    Fix: Reduce load to within rated capacity. If smoky condition does not clear up, stop the unit at once and check for further trouble. Serious damage may result if trouble is not corrected.

Compiled from service & troubleshooting documentation across every generator set that uses the Cummins/Onan 6 - 3.25 inch (82.55 mm) x 2.875 inch (73 mm).

Maintenance schedule

ItemSpecCapacityPart #Interval
Air filterM-131825 hr Amazon eBay $69.99
Fuel filter—25 hr
Oil filter—25 hr
Battery—200 hr
Belt—6 hr
Coolant filter—100 hr
Oil1.66 pint—50 hr
Spark plug—100 hr

Pooled from every document that names this exact engine — confirm the interval and part number against your unit's serial number.

Common questions

What is the oil capacity of the Cummins/Onan 6 - 3.25 inch (82.55 mm) x 2.875 inch (73 mm)?

The Cummins/Onan 6 - 3.25 inch (82.55 mm) x 2.875 inch (73 mm) engine has an oil capacity of 1.66 liters.

What is the displacement of the Cummins/Onan 6 - 3.25 inch (82.55 mm) x 2.875 inch (73 mm)?

The Cummins/Onan 6 - 3.25 inch (82.55 mm) x 2.875 inch (73 mm) has a displacement of 0.782 liters with 2 cylinders.

Which generators use the Cummins/Onan 6 - 3.25 inch (82.55 mm) x 2.875 inch (73 mm) engine?

The Cummins/Onan 6 - 3.25 inch (82.55 mm) x 2.875 inch (73 mm) powers 1 generator set(s), including Cummins/Onan GSP-1.

How often should you change the oil in the Cummins/Onan 6 - 3.25 inch (82.55 mm) x 2.875 inch (73 mm)?

The Cummins/Onan 6 - 3.25 inch (82.55 mm) x 2.875 inch (73 mm) oil change interval is every 50 hours.

What is a common problem with the Cummins/Onan 6 - 3.25 inch (82.55 mm) x 2.875 inch (73 mm) engine?

A commonly reported issue on generators using the Cummins/Onan 6 - 3.25 inch (82.55 mm) x 2.875 inch (73 mm) is: Engine will not start when cranked. Cause: Air in fuel system. Fix: Bleed the fuel system..