The Cummins/Onan KT2300-G is a 37.7 L 12-cylinder engine rated at 1800 rpm, producing up to 679 kW. It powers generator sets from Cummins/Onan, including the 500 DFX-57R, 600 DFX-4R and 600 DFX-4XR. It holds 151.4 L (40.0 gal) of oil and 207.9 L (54.9 gal) of coolant.
Maintenance schedule
| Item | Spec | Capacity | Part # | Interval | |
|---|
| Air filter | | | — | | |
| Fuel filter | spin-off, throw-away unit | | — | 200 hr | |
| Oil filter | spin-off throw away elements; replace at every oil change | | — | | |
| Battery | specific gravity 1.280 at 80F | | — | | |
| Belt | adjust to 1/2 inch depression between pulleys | | — | | |
| Coolant | check for rust or scale formation; flush if necessary | 207.9 litres | — | | |
| Coolant filter | replace periodically per General Maintenance section; compatible with plain water or ethylene glycol antifreeze; not compatible with stop-leak additives | | — | | |
| Oil | | 151.0 litres | — | 8 hr | |
Pooled from every document that names this exact engine — confirm the interval and part number against your unit's serial number.
Procedures
5Governor speed adjustment adjustment
⚠ Be prepared to assume manual control if adjustments are incorrect
Tools: screwdriver
- Remove four screws and cover from governor controller
- Disconnect wire from TB11-22 to disconnect starter solenoid
- Place Run-Stop-Remote switch to RUN; governor should stay at minimum fuel position
- Return switch to STOP and reconnect wire at TB11-22
- Position speed control rheostat to midrange (out 5 turns from low rpm)
- Adjust speed reference potentiometer counterclockwise four complete turns
- Start engine; adjust speed reference potentiometer clockwise/counterclockwise to reach correct rpm
- Adjust gain potentiometer clockwise then counterclockwise until stable and responsive
- Load and unload engine several times to confirm gain adjustment
- Shut down and restart engine to confirm no overspeed
- Replace governor control box cover
Generator support alignment to skid base installation
⚠ Generator support must be aligned to prevent premature bearing failure, vibration, drive disc failure
Tools: feeler gauge
- Set unit on mounting foundation with vibration isolators between skid base and foundation
- Secure skid base to isolators and isolators to foundation
- Remove two mounting bolts and use as jackscrews
- Raise generator and remove shims from between generator and support and skid base
- Adjust jackscrew tension and allow generator to hang free
- Measure clearance from skid base top to each generator support surface with feeler gauge
- Add 0.010 in (0.254mm) to each side to determine shim amount
- Turn jackscrews to allow clearance for placing shims
- Lower generator onto shims using jackscrews
- Recheck total clearance equals base-to-support clearance plus 0.010 in
- Remove jackscrews and reinstall as mounting bolts through support, shims, and skid base
- Secure and lock mounting bolts in place
Out-of-service protection (storage, up to six months) maintenance
⚠ For storage beyond six months refer to Cummins Service manual
Tools: tape
- Start and operate engine until thoroughly warm; disconnect fuel lines to filter and injector drain line
- Start engine on diesel fuel, then switch to preservative oil and run 5-10 minutes, stop engine and reconnect fuel lines
- Drain oil sump, fuel filters and fuel tank, reinstall drain plugs
- Disconnect electrical wiring, turn fuel pump shutoff valve fully counterclockwise, spray lubricating oil into intake manifold while cranking slowly
- Cover all openings with tape
- Drain coolant unless permanent antifreeze with rust inhibitor is used
- Store engine in dry, uniform temperature area
- Bar engine crankshaft two or three revolutions every three to four weeks
Preparing a stored engine for service maintenance
⚠ Do not smoke while servicing batteries - explosive gases emitted
- Clean accumulated dirt from exterior, remove covers, tape and wrappings
- Use suitable cleaner to remove rust preventive compound from unpainted surfaces
- Refill crankcase with clean lubricating oil; flush and fill cooling system
- Check coolant level, adjust or refill as necessary
- Connect batteries
- Verify no loads are connected to generator
- Perform prestart servicing and start engine
- Apply load to at least 50 percent of rated capacity
- Check all gauges read correctly
Priming the oil system maintenance
Tools: hand or motor-driven priming pump
- Remove oil inlet line from turbo-charger housing, fill bearing housing with clean oil, replace line, repeat for second turbo
- Fill crankcase to L (low) mark on dipstick
- Remove plug from head of oil filter housing and connect priming pump from clean lubricating oil source
- Prime until 30 psi (207 kPa) pressure is obtained
- Disconnect wire from fuel solenoid valve, close throttle, crank engine maintaining 15 psi (103 kPa) external prime for 15 seconds
- Remove external priming equipment, replace plug in filter housing, torque 15-20 lb-ft (20-27 N.m)
- Reconnect wire to fuel shut-off valve
- Complete oil fill to H (high) mark on dipstick
Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.
Common questions
What is the oil capacity of the Cummins/Onan KT2300-G?
The Cummins/Onan KT2300-G engine has an oil capacity of 151.4 liters.
What is the displacement of the Cummins/Onan KT2300-G?
The Cummins/Onan KT2300-G has a displacement of 37.7 liters with 12 cylinders.
Which generators use the Cummins/Onan KT2300-G engine?
The Cummins/Onan KT2300-G powers 3 generator set(s), including Cummins/Onan 500 DFX-57R, Cummins/Onan 600 DFX-4R, Cummins/Onan 600 DFX-4XR.
How often should you change the oil in the Cummins/Onan KT2300-G?
The Cummins/Onan KT2300-G oil change interval is every 8 hours.
What is a common problem with the Cummins/Onan KT2300-G engine?
A commonly reported issue on generators using the Cummins/Onan KT2300-G is: Weakness and Sleepiness. Fix: Get out into fresh air immediately..