Testing & Adjusting

Usage:

Introduction; Troubleshooting

Troubleshooting can be difficult. On the following pages there is a list of possible problems. To make a repair to a problem, make reference to the cause and correction.

This list of problems, causes, and corrections, will only give an indication of where a possible problem can be, and what repairs are needed. Normally, more or other repair work is needed beyond the recommendations in the list. Remember that a problem is not normally caused only by one part, but by the relation of one part with other parts. This list can not give all possible problems and corrections. The serviceman must find the problem and its source, then make the necessary repairs.

1. Contactor Switch For Water Temperature Does Not Activate Shutoff Solenoid.

2. Contactor Switch For Water Temperature Activates Shutoff Solenoid At Wrong Temperature.

3. Contactor Switch For Oil Pressure Fails To Activate Shutoff Solenoid.

4. Shutoff Solenoid Fails To Stop Engine.

5. Shutoff Solenoid Prevents Engine Start.

6. Clutch will not engage (slips), heats or lever moves to released position.

7. Clutch shaft has too much end play.

8. Clutch bearings have short service life.

9. Mechanical Shutoff Fails To Stop Engine Because Of Low Oil Pressure.

10. Mechanical Shutoff Does Not Stop Engine When Coolant Temperature Is Too High.

11. Mechanical Shutoff Will Not Let Engine Start.

12. Electrical Indicators Give Wrong Readings.

13. Automatic Start/Stop Systems.

a: No Supply Of Standby Current-Lockout Light Activated

b: No Supply Of Standby Current-No Lockout Light

c: Standby Current Supply Stops Before Normal Current Returns

d: Operation Of Standby System When Standby Current Is No Longer Needed

Problem 1: Contactor Switch For Water Temperature Does Not Activate Shutoff Solenoid

Probable Cause:

1. Wrong Connections

Connect battery to C and shutoff solenoid to NO connections. Check connections to other components or make installation of new wiring.

2. Failure of Shutoff Solenoid

Check the shutoff solenoid.

3. Low Water Level in Cooling System

Fill the cooling system.

4. Wrong Setting of Switch

Make a test of temperature setting and if necessary install new contactor switch with correct setting. See specifications.

Problem 2: Contactor Switch For Water Temperature Activates Shutoff Solenoid At Wrong Temperature

Probable Cause:

1. Wrong Setting of Switch

Make a test of temperature setting and if necessary install new contactor switch with correct setting. See specifications.

Problem 3: Contactor Switch For Oil Pressure Fails To Activate Shutoff Solenoid

Probable Cause:

1. Wrong Connections

Check connections, wiring and correct where necessary

2. Wrong Setting of Switch

Test switch. If necessary, install new switch.

Problem 4: Shutoff Solenoid Fails To Stop Engine

Probable Cause:

1. Wrong Connections

Check connections and wiring.

2. Plunger Shaft Adjustment Wrong

Make adjustment to plunger shaft.

3. Wrong Plunger in Shutoff Solenoid

Install the correct plunger shaft

4. Not Enough Plunger Travel

Make adjustment to plunger shaft or replace solenoid if necessary.

5. Wrong Shutoff Solenoid

Check engine parts manual for correct solenoid for either energized to run or energized to shutoff control logic systems.

Problem 5: Shutoff Solenoid Prevents Engine Start

Probable Cause:

1. Shutoff Solenoid Does Not Operate Correctly

Energized to shutoff or energized to run type: Operate the control for the shutoff solenoid. Listen for a noise. A shutoff solenoid makes noise when it works. If it makes noise but the engine still does not start, remove the shutoff solenoid. Try to start the engine. If the engine starts, the shutoff solenoid is either not installed correctly or it is bad. Make reference to Testing And Adjusting.

Problem 6. Clutch will not engage (slips), heats or lever moves to released position.

Probable Cause:

A. Wrong adjustment.

Make adjustment to clutch engagement lever pull.

B. Alignment of flywheel and flywheel housing mounting face and bores.

Check and make adjustment to alignment.

C. Overload on clutch.

Reduce load or reduce engine speed when engaging clutch.

Problem 7. Clutch shaft has too much end play.

Probable Cause:

A. Bearing worn of adjustment wrong.

Replace and/or make adjustment to shaft bearing.

Problem 8. Clutch bearing has short service life.

Probable Cause:

A. Too much bearing clearance.

Replace and/or make adjustment of shaft bearing.

B. Side load too high.

Make a reduction of side load.

Problem 9: Mechanical Shutoff Fails To Stop Engine Because Of Low Oil Pressure

Probable Cause:

1. Plunger is Held in Normal Run Position or a Spring is Broken

Disassemble and clean parts. Install new parts if needed.

Problem 10: Mechanical Shutoff Does Not Stop Engine When Coolant Temperature Is Too High

Probable Cause:

1. Oil Lines Have a Restriction

Clean oil lines, make replacements as necessary.

2. Control Valve Does Not Work Correctly

Clean control valve, make replacement if necessary.

3. Defect In Oil Pressure Shutoff

Clean oil pressure shutoff. Install new parts if necessary.

Problem 11: Mechanical Shutoff Will Not Let Engine Start

Probable Cause:

1. Control Has Not Been Set for Start

Set the control for start.

2. Spring is Broken

Install new spring.

3. High Water Temperature

Let engine cool.

Problem 12: Electrical Indicators Give Wrong Readings

Probable Cause:

1. Wrong Connections

Check wiring connections to be sure they are correct.

2. Sending Units Have a Failure

Check the sending units and install new ones if necessary.

3. Resistor in 32 Volt Systems Has a Failure

Install a new resistor.

4. Wrong Sending Unit in System

Install correct sending unit.

5. Wrong Indicator

Install correct indicator.

Problem 13a: No Supply Of Standby Current-Lockout Light Activated

Probable Cause:

1. Engine Does Crank But Will Not Start-Engine Speed Correct

a. Engine starting problem

No fuel.

Fuel rack not moving.

Governor not operating.

Wrong injection timing.

Very low air temperature.

Restriction in air inlet.

Low compression.

b. Switch problem

Water temperature switch has a failure.

Overspeed switch setting is low or has a failure.

c. Cranking panel problem

Overcranking timer has a failure.

See Troubleshooting section of Engine Control Panel Service Manual.

2. Engine Does Crank But Will Not Start-Cranking Speed Too Slow

a. Starting system problem

Battery does not have enough charge.

Faulty cable connections.

Starting motor has a failure.

b. Engine problem

High friction due to seizure.

c. Switch problem

Oil pressure switch has low setting.

3. Engine Does Not Crank

a. Starting system problem

Open circuit or very high resistance in circuit to the magnetic switch.

Magnetic switch has a failure.

Circuit breaker has a failure.

Problem 13b: No Supply Of Standby Current-No Lockout Light

Probable Cause:

1. Engine does not crank

a. Transfer switch problem

See Troubleshooting section of Transfer Switch Service Manual.

b. Cranking panel problem

Automatic engine control switch (ECS) is in the wrong position.

See Troubleshooting section of Engine Control Panel Service Manual.

2. Engine does operate-No voltage from generator

a. Generator problem

See topic "No AC Voltage" in Troubleshooting section of the Generator Service Manual.

Generator main circuit breaker not closed to transfer switch.

3. Engine does operate-Generator does give voltage

a. Transfer switch problem

See Troubleshooting section of Transfer Switch Service Manual.

Problem 13c: Standby Current Supply Stops Before Normal Current Returns

Probable Cause:

1. Lockout light activated

a. Engine problem

High water temperature.

Low oil pressure.

Overspeed.

No fuel.

Overload.

Mechanical failure.

See Troubleshooting section of Engine Control Panel Service Manual.

2. No lockout light

a. Generator problem

Malfunction developed during operation-see topic "No AC Voltage" in Troubleshooting section of Generator Service Manual.

Problem 13d: Operation Of Standby System When Standby Current Is No Longer Needed

Probable Cause:

1. Standby system still gives power

a. Transfer switch problem

See Troubleshooting section of Transfer Switch Service Manual.

2. Standby system does not give power, but engine keeps operating

a. Cranking panel problem

RR relay has a failure (not always fitted).

TD relay has a failure (not always fitted).

Automatic engine control switch (ECS) is in the MAN./START position.

See Troubleshooting section of Engine Control Panel Service Manual.

b. Problem on engine

Fuel pressure switch has a failure (not always fitted).

Rack stop solenoid has a failure or open in its circuit.

Fuel rack seizure in the open position (overspeed possible).

c. Transfer switch problem

Contacts welded, see Troubleshooting section of Transfer Switch Service Manual.

3. No current to the load, standby system stopped

a. Transfer switch problem

Main contacts welded.

See Troubleshooting section of Transfer Switch Service Manual.

Shutoff And Alarm System Components

Contactor Switch For Oil Pressure

Test Equipment
(1) 8T0853 Pressure Indicator (0 to 60 psi). (2) 3B7734 Pipe Nipple. (3) 3B6483 Cap. (4) Oil supply line. (5) 3B7263 Pipe Nipple. (6) 3B9389 Shutoff Cock Fitting. (7) 3B9389 Shutoff Cock Fitting. (8) 1F93369 Tees. (9) 5K3772 Hose Assemblies. (10) 44914 Tee.

Test Procedure

1. Remove the cover of the contactor switch and disconnect the wires from the normally closed (B or Blue) terminal.

2. Disconnect the oil supply line from the contactor switch and install the test equipment as shown.

3. Connect the 5K3772 Hose (9) from tee (10) to the contactor switch. Put the end of the other 5K3772 Hose (9) in a pan.

4. Connect the 8T0500 Circuit Tester between the common terminal and the normally closed terminal. The light of the circuit tester will be activated.

5. Close 3B9389 Shutoff Cock Fitting (7) and open the other 3B9389 Shutoff Cock Fitting (6).

6. Look at the pressure indicator, start the engine and run it at low idle rpm. The light must go out, with an increase in oil pressure, at the specification of the switch.

7. Close 3B9389 Shutoff Cock Fitting (6) and slowly open the other 3B9389 Shutoff Cock Fitting (7). The light must be activated, with a decrease in oil pressure, at the specification of the switch.

8. Stop the engine.

9. Connect the wire (s) to the normally closed terminal.

10. On contactor switches with a button or a control knob either push the button or turn the knob to the OFF position.

11. Close 3B9389 Shutoff Cock Fitting (7) and open the other 3B9389 Shutoff Cock Fitting (6).

12. Start the engine and run it at low idle rpm.

13. Put a jumper wire between the common terminal and the normally closed terminal. This will check the system beyond the contactor switch.

14. Remove the jumper wire.

Adjustment of Micro Switch Type Contactor

Contactor Switch For Oil Pressure (Micro Switch Type)
(11) Set for start button. (12) Adjustment screw. (13) Spring. (14) Locknut. (15) Contact button.

1. Loosen locknut (14) and turn adjustment screw (12) counterclockwise to make a decrease in the tension of spring (13).

Wiring Connections
(D) Normally closed B terminal. (E) Normally open W terminal. (F) Common R terminal.

2. Disconnect the wires from the normally closed terminal of the switch.

3. Start the engine and run it at low idle rpm.

4. Close 3B9389 Shutoff Cock Fitting (6) and slowly open the other 3B9389 Shutoff Cock Fitting (7) until the pressure indicator shows the pressure specification at which the switch must close with a decrease in pressure. Close 3B9389 Shutoff Cock Fitting (7).

5. Make sure the set for start button (13) is in the RUN position.

6. Connect the 8T0500 Circuit Tester between the common terminal and the normally closed terminal. The light of the circuit tester must not be activated.

7. Turn adjustment screw (12) clockwise until the light of the circuit tester is activated.

8. Tighten the locknut.

9. To check the adjustment, close 3B9389 Shutoff Cock Fitting (7) and open the other 3B9389 Shutoff Cock Fitting (6).

10. Connect the wires to the normally closed terminal.

11. Close 3B9389 Shutoff Cock Fitting (6) and slowly open the other 3B9389 Shutoff Cock Fitting (7) until the engine stops or the alarm operates.

12. The pressure indicator must show the correct pressure specification of the switch as the engine stops or the alarm operates.

Contactor Switch For Water Temperature

Method of Checking

Heat Sink [Dimensions in mm (in)]

1. Make a heat sink as shown. Material can be brass, steel or cast iron. Drill a 23/32 inch hole through the plate and use a tap to make 1/2 inch NPT threads.

2. Put marks on the two contactor wires that connect the contactor to he circuit. Disconnect the two wires.

3. Remove the contactor and install a 3J5389 Plug. Install the contactor switch in the heat sink.

4. Put the heat sink and contactor in water as shown. Use blocks to support the heat sink at surface level.

5. Connect the 8T0500 Circuit Tester between the wires that connected the contactor to the circuit.

Test Of Contactor Switch
(1) 2F7112 Thermometer. (2) Fabricated heat sink.

6. Put the 2F7112 Thermometer in the water.

7. Use a torch to heat the water to the temperature range at which the contactor must activate. If the circuit tester light does not come on within the temperature range given in the specifications, make a replacement of the contactor.

8. Let the water temperature go down. If the circuit tester light does not go out within the temperature range given in the specifications, make a replacement of the contactor.

Pressure Switch With Time Delay

Oil Pressure Switch With Time Delay Installed (Typical Example)
(1) Junction block. (2) Pressure switch.

1. Disconnect the wires from pressure switch (2). Remove the pressure switch from the junction block (1).

2. Install an elbow, a short nipple, a shutoff valve, a short nipple and tee as shown in place of the pressure switch. Make sure that the valve is closed.

3. Install the pressure switch (2) and a 8T0848 Indicator in the open ends of the tee as shown.

4. Connect the 8T0500 Circuit Tester between the terminals of the pressure switch.

Test Tools Installed (Typical Example)

5. Start the engine. Open the shutoff valve a small amount. Look at the pressure on the 8T0848 Indicator. When the pressure gets to the range given in the specifications, the circuit tester light must go on.

6. Close the shutoff valve. Stop the engine. Open the shutoff valve a small amount. Look at the pressure on the 8T0848 Indicator. When the pressure gets to the range given in the specifications, close the valve. After five minutes open the valve fully. The circuit tester light must stay on a minimum of 30 seconds and a maximum of 15 minutes after the valve is fully opened.

Shutoff Solenoids

1. Make sure the linkage to which the solenoid is connected does not give more than the normal amount of restriction.

2. Connect a voltmeter between the terminals of the solenoid.

3. Activate the solenoid circuit. If the voltage shown on the meter is less than the needed voltage, the circuit has a failure. Check the other components of the circuit. If the voltage is the same or more than the needed voltage, make a replacement of the solenoid.

Contactor Switch For Overspeed

The original setting of the contactor switch for overspeed will stop the engine when the engine rpm is more than 18% above full load rpm. DO NOT check the adjustment of the contactor switch on the engine.

1. Connect the 6V2100 Multitach of the 6V3121 Group to the 5P7360 Generator Assembly.

2. Connect the 5L2277 Adapter to the contactor switch and generator assembly.

3. Install variable speed drill to the adapter.

Overspeed Contactor Switch
(1) Reset button. (2) Lock screws.

4. Connect the 8T0500 Circuit Tester between the N.O. and the C terminals of the contactor switch. The light must be off. If the light is on, push reset button (1).

5. Gradually make an increase in the rpm. Read the rpm on the tachometer at the moment the light of the circuit tester is activated. The reading will give the engine rpm (2 rpm on the scale for each rpm the input shaft is turned).

6. If needed, make an adjustment to the contactor switch by loosening lock screws (2). Turn the cap clockwise to lower the overspeed setting. Tighten the lock screws.

7. To check other components in the system, put a jumper wire between the C and N.O. terminals of the contactor switch.

Magnetic Pickup

1. Check the resistance of the magnetic pickup with the wires disconnected and the engine stopped. The resistance must be according to specifications.

2. Start the engine. Check the voltage output of the magnetic pickup with the engine running at normal speed. The output must be according to specifications.

(1) Clearance. (2) Locknut.

NOTE: If the voltage output is not correct according to specifications, check for the correct clearance (1) between the magnetic pickup and the flywheel gear teeth.

3. If the operation of the magnetic pickup is correct according to the specifications after the tests above, connect the wires and check the operation of the electronic speed switch.

Oil Pressure And Water Temperature Shutoff (Mechanical)

1. Make a restriction to the flow of air through the radiator or to the flow of coolant through the engine.

Mechanical Shutoff Group
(1) Oil pressure sensing valve. (2) Tee. (3) Water temperature sensing valve. (4) Shutdown cylinder.

2. Install a probe or a thermometer as close as possible to the control valve.

3. Run the engine. The engine must stop in less than one minute from the time that the temperature of the coolant gets to the opening temperature for the control valve.

4. If the engine stops at the correct temperature, both the control valve and the oil pressure shutoff are operating correctly. If the engine does not stop at the correct temperature, do the following steps:

5. Loosen one of the connections on the oil supply line for the oil pressure shutoff. If the engine stops running, make a replacement of the control valve. If the engine does no stop running from loosening the nut, stop the engine.

6. Check the lines and fittings and the parts in the shutoff housing for a problem. Make reference to the Systems Operation for information on how the parts work together.

7. Make replacements as necessary and go through Steps 1 through 4 again.

Rear Power Takeoff Clutches

Single Plate Clutch (3N9097 & 4W2650)

Typical Illustration

NOTE: After clutch has been installed on engine, hit output shaft sharply on the end to relieve any preload that may result due to resistance of pilot bearing being pressed into the flywheel.

(1) Bearing Adjustment (end clearance):

3N9097

Tighten bearing retainer until there is no clearance between cup and cone. Back off retainer two or three notches and assemble the lock. Strike output end of shaft to seat the inner bearing cup against the bearing retainer. The end play must be ... 0.15 to 0.25 mm (.006 to .010 in)

4W2650

Tighten bearing retainer until there is no clearance between cup and cone. Back off retainer one or two notches and assemble the lock. Strike output end of shaft to seat the inner bearing cup against the bearing retainer. The end play must be ... 0.10 to 0.18 mm (.004 to .007 in)

Clutch Engagement Check (On Engine): 3N9097

A torque of 295 to 392 N·m (214 to 291 lb ft) on the splined clutch lever shaft is required to engage the clutch.

4W2650

A torque of 146 to 192 N·m (108 to 142 lb ft) on the splined clutch lever shaft is required to engage the clutch.

Double Plate Clutch (4P2270, 4P3073, 2W4902, & 2W4900)

Typical Illustration

NOTE: After clutch has been installed on engine, hit output shaft sharply on the end to relieve any preload that may result due to resistance of pilot bearing being pressed into the flywheel.

(1) Bearing Adjustment (end clearance):

4P2270

Tighten bearing retainer until there is no clearance between cup and cone. Back off retainer four or five notches and assemble the lock. Strike output end of shaft to seat the inner bearing cup against the bearing retainer. The end play must be ... 0.27 to 0.34 mm (.011 to .014 in)

4P3073, 2W4902

2W4900

Clutch Engagement Check (On Engine): 4P2270, 2W4900

A torque of 182 to 240 N·m (135 to 178 lb ft) on the splined clutch lever shaft is required to engage the clutch.

4P3073, 2W4902

A torque of 295 to 392 N·m (214 to 291 lb ft) on the splined clutch lever shaft is required to engage the clutch.

Triple Plate Clutch (1W8856, 2W4906, & 2W4908)

Typical Illustration

NOTE: After clutch has been installed on engine, hit output shaft sharply on the end to relieve any preload that may result due to resistance of pilot bearing being pressed into the flywheel.

(1) Bearing Adjustment (end clearance):

2W4906, 2W4908

Tighten bearing retainer until 6.8 N·m (5 lb ft) is required to rotate shaft, no shims. Measure shim gap and add 0.33 mm (.013 in) to get proper shim thickness. Assemble shims and retainer. The end play must be ... 0.15 to 0.25 mm (.006 to .010 in)

1W8856

Clutch Engagement Check (On Engine): 1W8856

A torque of 295 to 392 N·m (214 ± 291 lb ft) on the splined clutch lever shaft is required to engage the clutch.

2W4906, 2W4908

A torque of 325 to 435 N·m (239 ± 320 lb ft) on the splined clutch lever shaft is required to engage the clutch.

Electric Shutoff System

Wiring Diagram (Fuel Shutoff Solenoid Energized To Shutoff)
(1) Magnetic pickup. (2) Crank terminate switch. (3) Dual speed switch. (4) Time delay relay. (5) Switch (N.O.). (6) Shutdown relay. (7) Battery. (8) Diode assembly. (9) Shutoff solenoid. (10) Starter motor.

Troubleshooting Procedure (Overspeed)

Troubleshooting Procedure (Crank Terminate)

Service Procedures

Service Procedure List

Service Procedure A: Overspeed Verify Test

Service Procedure B: Overspeed Calibration

Service Procedure C: Crank Terminate Speed Calibration

Service Procedure D: Oil Step Speed Calibration

Service Procedure E: Magnetic Pickup Check

Service Procedure A

Electronic Speed Switch (ESS)
(1) Verify button. (2) Reset button. (3) "LED" overspeed light. (4) Seal screw plug (overspeed). (5) Seal screw plug (crank terminate). (6) Seal screw plug (oil step).

Overspeed Verify Test

1. Run the engine at rated speed and push verify button (1) in for a moment. This will cause the speed switch to activate and cause engine shutdown.

NOTE: Any time the engine speed is 75 percent or more of the overspeed setting, engine shutdown will occur if the verify button is pushed.

Example: For an engine with a rated speed of 1800 rpm, the overspeed setting is 2124 rpm (see SPEED SPECIFICATION CHART and Note A). The overspeed verify test will cause shutdown of the engine at 75 percent (± 25 rpm) of the overspeed setting of 2124 rpm. In this example, 75 percent of 2124 rpm is approximately 1593 rpm. If the verify button is pushed at an engine speed of approximately 1593 rpm or above, engine shutdown will occur.

The "LED" overspeed light (3) will come on and stay on until the reset button is pushed after an overspeed switch shutdown. Before restarting the engine, push in reset button (2) for a moment. This will reset the speed switch, and the "LED" overspeed light (3) will go off. The emergency stop switch (ES) must now be manually reset before the engine can be started again

NOTE A: The engine overspeed setting rpm is 118 percent of rated engine rpm.

NOTE B: To verify overspeed shutdown system operation, push in the VERIFY button for a moment. The engine must shut down at 75 percent or more of overspeed setting.

NOTE D: Input Voltage: Maximum 40 VDC; Minimum 8 VDC.

Service Procedure B

Electronic Speed Switch (ESS)
(1) Verify button. (2) Reset button. (3) "LED" overspeed light. (4) Seal screw plug (overspeed). (5) Seal screw plug (crank terminate). (6) Seal screw plug (oil step).

Overspeed Calibration

1. Remove lockwire and seal from seal screw plugs (4), (5) and (6). Remove seal screw plug (4) from access hole for overspeed adjustment screw.

2. Use a small screwdriver and lightly turn overspeed adjustment potentiometer twenty turns in direction of "MAX ARROW" (clockwise).

NOTE: The overspeed adjustment screw is made so that it cannot cause damage to the potentiometer, or be removed, if the adjustment screw is turned too many turns in either direction.

3. Run the engine at 75 percent of desired overspeed setting rpm. Make reference to the SPEED SPECIFICATION CHART (in Service Procedure A).

4. With engine at 75 percent of overspeed setting rpm, push VERIFY button (1) and hold in. Turn overspeed adjustment potentiometer in the direction opposite of "MAX ARROW" (counterclockwise) slowly until "LED" overspeed light (3) comes ON. Engine will shut down if speed switch is connected to the fuel shutoff solenoid and/or the air inlet shutoff solenoid.

5. To reset speed switch, push in reset button (2).

6. Slowly turn overspeed adjustment potentiometer approximately one turn clockwise and do Steps 3, 4 and 5 again.

NOTE: More adjustment may be needed to get the correct setting. Turn adjustment potentiometer clockwise to increase speed setting, and counterclockwise to decrease speed setting. Turn adjustment potentiometer very slowly only a small amount at a time until adjustment is correct.

7. When the speed setting is correct, install seal screw plug (4) in overspeed adjustment access hole. Tighten screw to a torque of 0.20 ± 0.03 N·m (2 ± .3 lb in). Install the lockwire and seal (if crank termination and oil step adjustments are complete).

Service Procedure C

Electronic Speed Switch (ESS)
(1) Verify button. (2) Reset button. (3) "LED" overspeed light. (4) Seal screw plug (overspeed). (5) Seal screw plug (crank terminate). (6) Seal screw plug (oil step).

Crank Terminate Speed Calibration

1. Remove lockwire and seal from seal screw plugs (4), (5) and (6). Remove seal screw plug (5) from access hole for crank terminate adjustment screw.

2. Use a small screwdriver and lightly turn overspeed adjustment potentiometer twenty turns in direction of "MAX ARROW" (clockwise).

NOTE: The crank terminate screw is made so that it cannot cause damage to the potentiometer, or be removed, if the adjustment screw is turned too many turns in either direction.

3. Turn the crank terminate adjustment potentiometer twelve turns in a direction opposite of "MAX ARROW" (counterclockwise) for an approximate crank terminate setting.

4. Connect a voltmeter (6V7070 Multimeter or a voltmeter of same accuracy) with the positive lead at ESS-12 and the negative lead at ESS-5. Start the engine and make a note of the speed at which the system voltage is canceled (this is the speed at which the DC starter system disengages). See the SPEED SPECIFICATION CHART (in Service Procedure A) for the correct crank terminate speed.

NOTE: If this setting is not correct, do Steps 5, 6 and 7. If the setting was correct, go to Step 7.

5. Stop the engine and turn the crank terminate adjustment potentiometer one full turn in the correct direction (clockwise to increase and counterclockwise to decrease).

6. With the voltmeter still connected as in Step 4, start the engine and make a note of the speed at which the system voltage is canceled (this is the speed at which the DC starter system disengages). If needed, make more small adjustments until the crank terminate speed is correct.

7. Install seal screw plug (5) in crank terminate adjustment access hole. Tighten to a torque of 0.20 ± 0.03 N·m (2 ± .3 lb in). Install the lockwire and seal (if overspeed and oil step adjustments are complete).

Service Procedure D

Electronic Speed Switch (ESS)
(1) Verify button. (2) Reset button. (3) "LED" overspeed light. (4) Seal screw plug (overspeed). (5) Seal screw plug (crank terminate). (6) Seal screw plug (oil step).

Oil Step Speed Calibration

1. Remove lockwire and seal from seal screw plugs (4), (5) and (6). Remove seal screw plug (6) from access hole for oil step adjustment screw.

2. Use a small screwdriver and lightly turn oil step adjustment potentiometer twenty turns in the direction of "MAX ARROW" (counterclockwise). This will lower the oil step speed setting to its lowest value.

NOTE: The oil step adjustment screw is made so it cannot cause damage to the potentiometer, or be removed, if the adjustment screw is turned too many turns in either direction.

3. Use a 6V7070 Multimeter (or a voltmeter of same accuracy) to check for positive (+) voltage at terminal ESS-13 [negative (-) voltage is at terminal ESS-5].

4. Make reference to SPEED SPECIFICATION CHART (in Service Procedure A). For a particular engine rating, find the specified rpm in column for Oil Step Speed Setting. Run the engine at this specified rpm.

5. With the engine running, look into the oil step adjustment access hole. A red "RED" (light emitting diode) light will be ON. A positive (+) voltage will be seen at terminal ESS-13, 9 seconds after "LED" light comes ON. Now turn the oil step adjustment potentiometer clockwise until the red light in the oil step access hole goes OFF. When the light goes OFF, this indicates that the oil step rpm setting is above the present running rpm of the engine. Slowly turn the adjustment potentiometer counterclockwise until the light comes back ON. After a 9 second delay, positive (+) voltage will again be seen at terminal ESS-13.

6. When the oil step speed setting is correct, install seal screw plug (6) into the adjustment access hole for the oil step function. Tighten plug to a torque of 0.20 ± 0.03 N·m (2 ± .3 lb in). If all other adjustments are complete (overspeed and crank terminate), install lockwire and seal.

Service Procedure E

Magnetic Pickup Check

1. Connect a 6V7070 Multimeter (or a voltmeter of same accuracy) to electronic speed switch common terminal (ESS-3) and signal terminal (ESS-4). Set the meter voltage scale to a scale greater than 1.5 VAC. Start the engine and run at idle rpm or 600 rpm (whichever is greater).

If the measured voltage is 1.5 VAC or more, the operation of the magnetic pickup is correct. If measured voltage is less than 1.5 VAC, go to Step 2.

Show/hide table

NOTICE

The magnetic pickup is an important part of the ETR Shutoff Protection System. It is required for crank terminate, overspeed and governing. Be ready to take action when the magnetic pickup is disconnected.

2. Stop the engine. Disconnect the wiring from the magnetic pickup at the plug-in connector and connect the voltmeter to magnetic pickup connector terminals. Start the engine and run at idle rpm or 600 rpm (whichever is greater).

If the measured voltage is 1.5 VAC or more, repair or replace the wiring between the magnetic pickup and the electronic speed switch. If the measured voltage is less than 1.5 VAC, go to Step 3.

Magnetic Pickup (Typical Illustration)
(1) Clearance dimension. (2) Locknut.

3. Remove the magnetic pickup from the engine flywheel housing and turn the flywheel until a gear tooth is directly in the center of the threaded opening for the magnetic pickup. Install the magnetic pickup again in the threads of the flywheel housing.

4. Turn (by hand) in a clockwise direction until the end of the magnetic pickup just makes contact with the gear tooth. Now turn the magnetic pickup back out 1/2 turn (180 degrees in the counterclockwise direction) to get the correct air gap [clearance dimension (1)]. Now tighten locknut (2) to a torque of 45 ± 7 N·m (33 ± 5 lb ft).

NOTE: Do not let the magnetic pickup turn while locknut (2) is tightened.

Do Step 2 again. If voltage is still less than 1.5 VAC, replace the magnetic pickup.

Time Delay Relay

On/Off Time Delay (Relay)

Performance Check

A. Items Required For Check:

1. Battery or any DC source of 8 to 40 volts.

2. Voltmeter (6V7070 Multimeter or one of same accuracy).

3. Stop watch.

B. Bench Or Installed Test.

Connect or verify source voltage to relay terminals 8 (-) and 4 (+) [if bench testing, also connect positive (+) voltage to relay terminal 6]. All connections must be maintained until tests are complete.

NOTE: There will be voltage when the relay is closed. When relay is open, there will be no voltage [voltage may be positive (+) or negative (-) when relay is tested on engine; when bench testing, voltage will always be positive (+)].

1. Use the voltmeter to verify chart that follows:

2. (a) Apply positive (+) source voltage to terminal 1 and immediately verify the chart that follows (do not leave voltage on terminal 1 for more than 60 seconds):

(b) Remove positive (+) source voltage from terminal 1. Use a stop watch and check the time from the moment of removal to verify chart that follows:

3. (a) Apply positive (+) source voltage to terminal 2.

NOTE: If bench testing, Step 3 can be used as stated. When the unit is installed on the engine, all wires must be disconnected from Terminal 2 to prevent a direct short.

Check the time form the moment voltage is applied to verify chart that follows (do not leave voltage on terminal 2 for more than 60 seconds):

(b) Remove positive (+) source voltage from terminal 2. Check the time from the moment of removal to verify chart that follows:

4. Remove wire from terminal 4 and verify chart that follows:

Instruments And Indicators

Oil Pressure Sending Units

Sending Unit For Oil Pressure
(1) Terminal. (2) Fitting

1. Connect the sending unit to a pressure source that can be measured with accuracy.

2. Connect an ohmmeter between fitting (2) and terminal (1).

3. Take resistance readings at the pressure shown in SENR2570.

4. If a unit does not have the correct resistance readings, make a replacement of the unit.

Water Temperature Sending Unit

1. Connect an ohmmeter between terminal (1) and nut (2). Put bulb (3) in a pan of water. Do not let the bulb have contact with the pan.

2. Put a thermometer in the water to measure the temperature.

Sending Unit For Water Temperature
(1) Terminal. (2) Nut. (3) Bulb.

3. Take resistance readings at the temperatures shown in SENR2570.

4. If a unit does not have the correct resistance readings, make a replacement of the unit.

Electric Indicators

1. Put the indicator in position with the letters horizontal and the face 30 degrees back from vertical.

Wiring Diagram For Test
(1) Terminal (for test voltage). (2) Test resistance.

2. Connect the indicator in series with the power source and the middle test resistance shown in the chart.

3. Let the indicator heat at the middle resistance for five minutes, then check the pointer position for all of the resistance given.

Mechanical Indicators For Temperature

Direct Reading Indicator

Gauge With Color Code

Two types of mechanical indicators are available. The first type has a direct reading face. The second type has color codes on the face to show different ranges of operation. White, green and red show the cold, normal and hot ranges respectively.

To check these indicators, put the bulb of the indicator in a pan of oil. Do not let the bulb touch the pan. Put a thermometer in the oil to measure the temperature. Make a comparison of temperatures on the thermometer with the temperatures on the direct reading indicator. Refer to SENR2570 for the calibration chart.

Mechanical Indicators For Oil Pressure

Direct Reading Indicator

Gauge With Color Code

Two types of mechanical indicators are available. The first type has a direct reading face. The second type has color codes on the face to show different ranges of operation. Red, white and green show the low pressure, pressure at low idle and normal pressure ranges respectively.

To check these indicators connect the indicator to a pressure source that can be measured with accuracy. Make a comparison of pressure on the indicator of test equipment with the pressures on the direct reading indicator. Refer to SENR2570 for the calibration chart.