Cummins/Onan KtA38 Generator Set

⚠ Do not break or remove the lockwire.

⚠ Do not use the ST-1224 if stop crank adjustment is required.

Tools: ST-1224 Tachometer drive adapter (2:1 ratio), tachometer, 1/16 inch hex allen wrench

1. Remove the tachometer drive adapter.
2. Install the ST-1224 in place of the standard drive adapter; connect the tachometer and overspeed stop switch to the ST-1224.
3. Start the engine and warm to operating temperature.
4. Set the engine speed to the appropriate overspeed switch set speed in Table 1-3 as indicated by the tachometer.
5. Remove the round head dust cover screw marked 2 from the top of the switch.
6. Insert a 1/16 inch hex allen wrench into the adjusting screw located just below the surface of the cover.
7. Turn the adjusting screw counterclockwise to lower the engine shut off speed; clockwise to raise it.
8. Replace the dust cover screw.
9. Reset the switch by pushing the reset button on top of the switch.
10. Replace the ST-1224 with the original drive adapter and reconnect the cables.

⚠ Over-tensioning of alternator belts can result in premature accessory drive bushing wear and seal leakage.

Tools: GT-1293 Burroughs Tension Gauge

1. Loosen the alternator and adjusting link mounting capscrews.
2. Loosen the jam nuts on the adjusting screw.
3. Turn the adjusting screw clockwise to tighten the belt tension.
4. Check the belt tension with a gauge.
5. Tighten the jam nuts on the adjusting screw to 55 Nm [40 ft-lb].
6. Tighten the adjusting link and alternator mounting capscrews to 55 Nm [40 ft-lb].
7. Check the belt tension again.

Tools: ST-669 Torque Wrench Adapter

1. Adjust the crossheads on the cylinder that has both valves closed.
2. Loosen the crosshead adjusting screw locknuts on the intake and exhaust valve crossheads.
3. Turn the adjusting screw out at least one turn.
4. Hold the crosshead down against its guide.
5. Turn the adjusting screw in until it touches the top of the valve stem but does not raise the crosshead.
6. Hold the adjusting screw and tighten the lock nut to the torque value.

⚠ The dipstick will break if the scribe mark is too deep.

Tools: scribe

1. Drain the oil from the pan.
2. Install the dipstick in the dipstick tube.
3. Use clean 15W-40 oil to fill the oil pan to the specified low level.
4. Remove the dipstick and scribe a mark across the dipstick at the oil level. Mark the low level with an L.
5. Install the dipstick and add additional oil to the specified full level.
6. Remove the dipstick and scribe a mark across the dipstick at the oil level. Mark the high oil level with an H.

⚠ Use only proper engine barring techniques; do not attempt to rotate the engine by pulling or prying on the fan.

Tools: Snap-On Model TQ12B or equivalent in-lb torque wrench, screwdriver adapter, ST-669 Adapter

1. Turn the crankshaft in direction of rotation until the No. 1 'VS' mark appears; verify both intake and exhaust valves are closed for cylinder No. 1.
2. Tighten the injector hold-down capscrew to 30 to 35 ft-lbs [41 to 47 N·m].
3. Turn the adjusting screw down until the plunger contacts the cup and advance an additional 15 degrees to squeeze the oil from the cup.
4. Loosen the adjusting screw one turn; tighten with an in-lb torque wrench and screwdriver adapter to the cold-setting value.
5. Hold the adjusting screw and tighten the locknut to the specified torque.
6. Turn the crankshaft to the next 'VS' mark per firing order and repeat.

⚠ The injector plunger is under spring tension. Do NOT allow the tool to slip.

Tools: 3822575 adjustment kit, 3822574 rocker lever actuator, ST-669 adapter

1. Install injector and valve adjustment kit, Part No. 3822575.
2. Adjust indicator tip to touch top of injector plunger.
3. Lower indicator 12.25 mm [0.5 inch] and lock support.
4. Depress rocker lever until injector bottoms two or three times.
5. Hold plunger bottomed and set indicator to ZERO.
6. Turn adjusting screw until indicator reads specified travel.
7. Tighten locknut; verify setting.

⚠ Be sure the injector and valve set markings are in proper alignment with the indicator mark.

Tools: feeler gauge

1. Loosen the locknut and back off the adjusting screw.
2. Insert a feeler gauge between the rocker lever and the top of the crosshead.
3. Turn the screw down until the lever just touches the gauge.
4. Lock the adjusting screw in this position with the locknut and torque to specification.

⚠ Use the correct chart for the engine being serviced or the parts will be damaged.

Tools: 3376592 Inch Pound Torque Wrench, ST-669 Torque Wrench Adapter, feeler gauge

1. Select a feeler gauge for the correct valve lash specification and insert the gauge between the rocker lever and the crosshead.
2. Torque wrench method: use Part No. 3376592 inch pound torque wrench and tighten the adjusting screw to 0.68 Nm [6 in-lb].
3. Feel method: use a screwdriver and turn the adjusting screw only until the lever touches the feeler gauge.
4. The adjusting screw must not turn when the locknut is tightened.
5. Tighten the locknut to the value indicated.
6. The feeler gauge must slide backward and forward with only a slight drag.
7. Attempt to insert a feeler gauge 0.03 mm [0.001 in] thicker; the lash is not correct when the thicker gauge will fit.
8. Repeat until clearance is correct on both intake and exhaust valves.

⚠ Use the correct chart for the engine or the parts will be damaged.

⚠ Crosshead adjustment must always be made before adjusting the valves.

Tools: 3376592 inch pound torque wrench, 3822575 injector and valve adjustment kit, 3822574 rocker lever actuator, ST-669 torque wrench adapter

1. Steam clean engine before removing rocker lever covers.
2. Remove rocker lever covers and related components.
3. Align valve set (VS) mark on damper or flywheel with pointer.
4. Determine cylinder in position; crossheads and valves ready when all valves closed.
5. Adjust crossheads before adjusting valves.
6. Adjust valves to lash specification with feeler gauge.
7. Adjust injectors per PT (type D) or STC/HVT method.
8. Tighten locknuts and reinstall rocker lever covers.

Tools: dial indicator, feeler gauge, long capscrew

1. Remove the exhaust and intake piping from the turbocharger to expose the ends of the rotor assembly.
2. Remove one capscrew from the front plate and replace it with a long capscrew; attach an indicator and register the point on the end of the rotor shaft.
3. Push the shaft from end-to-end and note the total indicator reading.
4. Check the radial clearance on the compressor wheel only by pushing the wheel toward the side of the bore and using a feeler gauge between the wheel vane tips and the bore.
5. If end clearances exceed the limits, remove the turbocharger and replace it with a new or rebuilt unit.
6. Install the exhaust and intake piping to the turbocharger.

⚠ Parts originally supplied must not be deviated from without qualifying agency approval (Underwriters Laboratory / Factory Mutual Research).

1. Contact operating personnel responsible for the fire protection system and obtain approval.
2. Close all cooling system drains.
3. Remove the heat exchanger cap; check or fill engine coolant supply; open the water filter inlet and outlet valves.
4. Prelubricate the engine with API Class CD or CC oil, SAE 15W40 or 20W40; on turbocharged engines add 2 to 3 oz. [60 cc] oil to the turbocharger oil inlet line.
5. Check the crankcase oil level and fill to the high mark on the dipstick.
6. Remove the fuel pump solenoid wire and crank the engine through two cranking cycles using the fire pump controller.
7. Turn the governor idle adjusting screw counterclockwise 6 turns to permit near idle speed at initial start-up.
8. Verify the lube oil system is under pressure.
9. Operate the engine for 8-10 minutes and look for leaks, unusual noises or other indications of improper operation.
10. Set the overspeed stop switch.
11. Stop the engine and check the engine oil and expansion tank coolant levels; top off if necessary; clean the raw water strainer.
12. Start the engine and bring it to the fire pump required operating speed; adjust the raw water pressure regulator and readjust speed if necessary.
13. Lock the governor lever (naturally aspirated) or max speed screw (turbocharged) in position.
14. Shut off the engine; notify operating personnel and obtain authorized signature of acceptance.

⚠ Holes, loose end seals, dented sealing surfaces and other damage require immediate element replacement.

⚠ Pull the cover and element straight out to avoid damage.

1. Wipe dirt from the cover and upper portion of the air cleaner before disassembly.
2. Loosen the wing bolt and band clamp securing the dust pan.
3. Loosen the wing nut and remove the dust shield from the dust pan. Clean the dust pan and shield.
4. Remove the wing nut securing the primary element and inspect the rubber sealing washer.
5. Remove the dirty cleaner element and install the new primary element.
6. Make sure the rubber sealing washer is in place under the wing nut before tightening.
7. Assemble the dust shield and dust pan and secure with the band clamp.