Cummins/Onan ES-1788 Generator Set

1. Loosen alternator bolt that passes through elongated slot in mounting bracket.
2. Slide alternator until fan belt tension of 60 lbs. (267 N) is obtained.
3. Tighten alternator mounting bolt to lock alternator in place.
4. Check tension and repeat if necessary.

⚠ Hot coolant is under pressure; do not loosen cap while engine is hot.

1. Disconnect coolant heater from AC power, if equipped.
2. Allow system to cool; remove radiator pressure cap.
3. Open radiator drain cock and disconnect lower radiator hose.
4. Remove cylinder block drain plug or disconnect tank heater.
5. Allow system to drain completely.
6. Reinstall cylinder block drain plug or reconnect tank heater.
7. Close radiator drain cock and reconnect lower radiator hose.
8. Fill cooling system with clean water; do not install radiator cap.
9. Operate engine for 5 minutes with coolant temperature above 194°F (90°C).
10. Shut off engine and drain cooling system; repeat flush if water is dirty.
11. When flushing water is clean, drain completely and refill with coolant.

⚠ Overtightening of the clamp will tear breather cap.

1. Remove breather cap and lift out breather element.
2. Clean breather cap and element in cleaning solvent.
3. Dry thoroughly with low pressure air, under 35 psi (241 kPa).
4. Install clean or new breather element in valve cover; do not pack element into valve cover.
5. Install clamp, breather cap, and connect breather tube.

⚠ Fuel presents fire or explosion hazard. Keep ignition sources away.

1. Close fuel tank shut-off valve.
2. Clean all dirt from around filter, filter base and surrounding area.
3. Remove filter retaining clip or clips.
4. Remove old filter and dispose of properly.
5. Install new fuel filter and prime the fuel system.

⚠ Do not reuse element more than twice. If element has a small hole, replace it.

1. Remove dust cap.
2. Clean dust and debris from rubber dust collector in cap.
3. Remove wing nut and air filter element.
4. Clean by directing dry, clean, low-pressure air (30 psi/207 kPa) up and down pleats on inside of element.
5. If extremely dirty, wash by soaking in mild detergent and water for 15 minutes, then rinse thoroughly.
6. Air dry element for minimum 24 hours; do not dry with compressed air or at temperatures greater than 150°F (66°C).
7. Reassemble, making certain dust cap side marked TOP is facing out.

⚠ Crankcase pressure can blow out hot oil and cause serious burns. Do NOT check oil while generator is operating.

1. Start generator set and warm engine to operating temperature, then shut off.
2. Place Run/Stop/Remote switch at STOP and disconnect negative battery cable.
3. Remove oil drain plug or open drain valve; collect oil in waste container; replace plug or close valve.
4. Torque oil drain plug to 60-70 ft-lb (81-95 N·m).
5. Unscrew oil filter and discard; clean filter mounting surface.
6. Apply light coat of oil to gasket of new filter and fill filter with clean new oil.
7. Install filter and tighten 1/4 to 1/2 turn by hand after seal touches bracket; do not overtighten.
8. Fill crankcase to FULL mark on dipstick.
9. Reconnect negative battery cable, start engine and check for oil leaks.
10. Shut off engine, wait 15 minutes, check oil level and add oil if required.

1. Remove oil inlet line from turbocharger housing.
2. Fill bearing housing with clean engine lubricating oil.
3. Replace oil inlet line and secure.

⚠ Fuel is under extremely high pressure and can penetrate skin causing blood poisoning or infection. Wear protective gloves and face mask.

1. Loosen fuel injection line connecting nut at each nozzle holder.
2. Energize starting motor by placing Run/Stop/Remote switch in Run position.
3. After 30 seconds, place switch in Stop and pause two minutes to cool starter.
4. Discontinue priming when fuel flows from all high pressure lines.
5. Tighten connection nuts and torque to 18 ft-lbs (24 N·m).

⚠ Fuel presents fire or explosion hazard.

1. Check fuel level in tank and open shut-off valve.
2. Loosen fuel filter to injection pump line at injection pump fuel inlet fitting.
3. Actuate priming lever on transfer pump until fuel flows from fitting.
4. If camshaft lobe is up, turn engine one revolution to permit hand priming.
5. Tighten fuel line at injection pump inlet.

1. Remove thru-bolt.
2. Lift off air cleaner cover.
3. Lift off air cleaner element.
4. Install new air cleaner element after cleaning cover of dust and debris.