Testing And Adjusting

Usage:

Introduction

NOTE: For Specifications with illustrations, make reference to SPECIFICATIONS for 3406B INDUSTRIAL & MARINE ENGINE ATTACHMENTS, Form No. SENR4024. If the Specifications in Form SENR4024 are not the same as in the Systems Operation and the Testing and Adjusting, look at the printing date on the back cover of each book. Use the Specifications given in the book with the latest date.

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.

12. Electrical Gauges Give Wrong Readings.

13. PSG Governors.

a. Engine Speed Does Not Have Stability.

b. Vibration At Governor Output Shaft.

c. Fuel Control Response When The Engine Is Started Is Not Acceptable.

d. Engine Has Slow Response To A Change In Speed Setting Or Load.

e. No Output From Governor.

f. Engine Will Not Drive Full Rated Load.

g. Load Sharing Between Paralleled Units Is Not Correct (One unit on zero droop all others on droop).

h. Load Sharing Between Paralleled Units Is Not Correct (all units on droop).

14. Automatic Start/Stop Systems.

Contactor Switch For Water Temperature Does Not Activate Shutoff Solenoid

Contactor Switch For Water Temperature Activates Shutoff Solenoid At Wrong Temperature

Contactor Switch For Oil Pressure Fails To Activate Shutoff Solenoid

Shutoff Solenoid Fails To Stop Engine

Shutoff Solenoid Prevents Engine Start

Clutch Will Not Engage (Slips), Heats Or Lever Moves To Released Position

Clutch Shaft Has Too Much End Play

Clutch Bearings Have Short Service Life

Mechanical Shutoff Fails To Stop Engine Because Of Low Oil Pressure

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

Mechanical Shutoff Will Not Let Engine Start

Electrical Gauges Give Wrong Readings

Engine Speed Does Not Have Stability

Vibration At Governor Output Shaft

Fuel Control Response When The Engine Is Started Is Not Acceptable

Engine Has Slow Response To A Change In Speed Setting Or Load

No Output From Governor

Engine Will Not Drive Full Rated Load

Load Sharing Between Paralleled Units Is Not Correct (one unit on zero droop all the others on droop)

Load Sharing Between Paralleled Units Is Not Correct (all units on droop)

Automatic Start/Stop System

No Supply Of Standby Current

Standby Current Supply Stops Before Normal Current Returns

Operation Of Standby System When Standby Current Is No Longer Needed

Shutoff And Alarm System Components

Contactor Switch For Oil Pressure

3P1564 Pressure Gauge (0 to 60 psi).3B7734 Pipe Nipple, 1/8 in. × 3.5 in.3B6483 Cap.Two 3B7263 Pipe Nipples, 1/8 in. × 2 in.Two 3B9389 Shutoff Cock Fittings.Two 1F9369 Tees.44914 Tee.Two 5K3772 Hose Assemblies.8T500 Circuit Tester.

TEST EQUIPMENT
1. 3P1564 Pressure Gauge (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. 1F9369 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 from tee (10) to the contactor switch. Put the end of the other 5K3772 Hose in a pan.

4. Connect the 8T500 Circuit Tester between the common terminal and the normally closed terminal. The light of the circuit tester will be activated.

5. Close shutoff fitting (7) and open shutoff fitting (6).

6. Look at the pressure gauge, 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 shutoff fitting (6) and slowly open shutoff 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 shutoff fitting (7) and open shutoff 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

1. Loosen locknut (16) and turn adjustment screw (14) counterclockwise to make a decrease in the tension of spring (15).

CONTACTOR SWITCH FOR OIL PRESSURE (Micro Switch Type)
13. Set for start button. 14. Adjustment screw. 15. Spring. 16. Locknut. 17. Contact button.

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 shutoff fitting (6) and slowly open shutoff fitting (7) until the pressure gauge shows the pressure specification at which the switch must close with a decrease in pressure. Close shutoff fitting (7).

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

6. Connect the 8T500 Cicuit Tester between the common terminal and the normally closed terminal. The light of the circuit tester must not be activated.

7. Turn screw (14) clockwise until the light of the circuit tester is activated.

8. Tighten the locknut.

WIRING CONNECTIONS
D. Normally closed B terminal. E. Normally open W terminal. F. Common R terminal.

9. To check the adjustment, close shutoff fitting (7) and open shutoff fitting (6).

10. Connect the wires to the normally closed terminal.

11. Close shutoff fitting (6) and slowly open shutoff fitting (7) until the engine stops or the alarm operates.

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

Contactor Switch For Water Temperature

Fabricated heat sink.2F7112 Thermometer.3J5389 Plug.8T500 Circuit Tester.

Method of Checking

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

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

HEAT SINK [Dimensions in mm (in.)]

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 8T500 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

8M2743 Gauge.8T500 Circuit Tester.

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

OIL PRESSURE SWITCH WITH TIME DELAY INSTALLED
1. Junction block. 2. Pressure switch.

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 8M2743 Gauge in the open ends of the tee as shown.

4. Connect the 8T500 Circuit Tester between the terminals of the pressure switch.

TEST TOOLS INSTALLED

5. Start the engine. Open the shutoff valve a small amount. Look at the pressure on the 8M2743 Gauge. 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 8M2743 Gauge. 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.

Oil Pressure And Water Temperature Shutoff (Mechanical)

3J5389 Plug.Two 5K9246 Connectors.Two 4K7965 Hose Assemblies.60210 Tee.8M2743 Gauge.5P7486 Valve.

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

2. Install a probe from the 8T470 Thermistor Thermometer Group as close as possible to control valve (2).

3. Start 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 of the control valve. If it does not stop, do the steps that follow.

SHUTOFF SYSTEM
1. Line (oil supply). 2. Control valve (water temperature). 3. Line (oil return). 4. Oil pressure shutoff.

CONTROL VALVE

4. Stop the engine. Disconnect oil lines (1 and 3) from control valve (2).

5. Remove the control valve and install the 3J5389 Plug.

6. Install a 5K9246 Connector and 4K7965 Hose Assembly to both lines (1 and 3).

7. Install the 60210 Tee on the hose assembly connected to line (1).

8. Install the 8M2743 Gauge on the tee.

9. Connect the last opening of the tee to the other hose assembly with the 5P7486 Valve. Make sure the valve is closed.

10. Start the engine. Run the engine at full load rpm.

11. Slowly open the 5P7486 Valve. Look at the pressure gauge. Oil pressure shutoff (4) must stop the engine when the oil pressure is between 50 and 60 kPa (7 and 9 psi). If the engine does not stop there is either a restriction in the lines (1 or 3), or the oil pressure shutoff has a failure.

12. Make repairs as necessary and do Step 11 again.

13. When the oil pressure shutoff stops the engine at the correct pressure, remove the tools and install control valve (2).

14. Do Steps 1, 2 and 3 again. If the control valve does not cause the engine to stop, make a replacement of the control valve.

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)

Procedure A

Overspeed Setting Calibration

ELECTRONIC OVERSPEED SWITCH
11. Verify button. 12. Reset button. 13. "LED" overspeed light. 14. Seal screw plug (overspeed). 15. Seal screw plug (crank terminate).

1. Remove lockwire and seal from seal screws (14 and 15). Remove seal screw (14) from access hole for overspeed adjustment screw.

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

NOTE: The overspeed adjustment screw is made so that it can not cause damage to the potentiometer or be removed if the adjustment screw is turned too much.

3. Run the engine at 75% of desired overspeed setting rpm. Make reference to the SPEED SPECIFICATION CHART.

4. With engine at 75% of overspeed setting rpm, push VERIFY pushbutton (11) and hold in. Turn O.S. (overspeed) adjustment potentiometer in the direction opposite of "MAX ARROW" (counterclockwise) slowly until "LED" overspeed light (13) comes on. Engine will shutdown if speed switch is connected to the fuel shutoff solenoid and/or air inlet shutoff solenoids.

5. To reset speed switch, push in reset button (12). Air inlet shutoffs must be manually reset.

6. Slowly turn O.S. (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 (14) for overspeed adjustment hole and install lockwire and seal.

Procedure B

Magnetic Pickup Adjustment

MAGNETIC PICKUP
16. Engine flywheel. 17. Locknut. 18. Air gap.

1. Stop engine.

2. Loosen magnetic pickup locknut (17).

3. Turn the magnetic pickup clockwise until contact is made with the teeth of the engine flywheel ring gear (16).

4. Turn the magnetic pickup counterclockwise one-half turn. This will give approximately 0.55 to 0.84 mm (.022 to .033 in.) clearance at location (18), between the end of the magnetic pickup and the teeth of the flywheel ring gear.

5. After the clearance is correct, tighten the magnetic pickup locknut to a torque of 45 ± 7 N·m (33 ± 5 lb.ft.). If the engine uses a 2301 Governor, tighten the magnetic pickup to a torque of 70 ± 14 N·m (50 ± 10 lb. ft.).

NOTE: Be sure the magnetic pickup does not turn when the locknut is tightened.

Procedure C

Crank Terminate Speed Adjustment

ELECTRONIC OVERSPEED SWITCH
11. Verify button. 12. Reset button. 13. "LED" overspeed light. 14. Seal screw plug (overspeed). 15. Seal screw plug (crank terminate).

1. Remove lockwire and seal from seal screws (14 and 15). Remove seal screw (15) from access hole for crank terminate adjustment screw.

2. Use a small screwdriver and lightly turn C.T. (crank terminate) adjustment potentiometer twenty turns in the direction of "MAX ARROW" (clockwise).

NOTE: The crank terminate adjustment screw is made so that it can not cause damage to the potentiometer or be removed if the adjustment screw is turned too much.

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

4. Start engine and make a note of the speed at which the starter disengages. See the SPEED SPECIFICATION CHART for the correct crank terminate speed.

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

5. Stop engine and turn adjustment potentiometer (clockwise to increase and counterclockwise to decrease) crank terminate speed.

6. Start and make a note of the speed at which the starter disengages. If needed, make more small adjustments until the crank terminate speed is correct.

7. Install seal screw (15) for crank terminate adjustment hole and install lockwire and seal.

Procedure D

Overspeed Verify Test

1. Run engine at rated speed, push verify button (11) in for a moment. This will cause the speed switch to activate and shutdown the engine.

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

EXAMPLE: For an engine with a rated speed of 1500 rpm the overspeed setting is 1770 rpm. The overspeed verify test will shut down the engine at 75% of the overspeed setting of 1770 rpm. In this example 75% of 1770 rpm is 1328 rpm. If the verify button is pushed at an engine speed of 1328 rpm or above the engine will shutdown.

The "LED" overspeed light (13) will come on and stay on until the reset button is pushed after an overspeed switch shutdown. To restart the engine, push in reset button (12) for a moment. This will reset the speed switch and the rack shutoff solenoid. The "LED" overspeed light (13) will go off. The air inlet shutoff must be manually reset.

NOTE C: To verify overspeed shutdown system operation, push in for a moment the verify push button. The engine must shutdown at 75% or more of overspeed setting.

NOTE D: Input Voltage: Maximum 37 VDC Minimum 8 VDC.

NOTE E: The engine overspeed setting rpm is 118% of rated engine rpm.

NOTE F: The magnetic pickup frequency (HZ) at the overspeed or cranking termination setting is calculated with the formula that follows:

If the rated speed of the engine is other than shown in the chart, the magnetic pickup frequency for the overspeed setting can be found according to NOTES E and F.

If a 2301 Governor is used, only one magnetic pickup is needed. Use the magnetic pickup from the overspeed group. Connect the wires from the magnetic pickup to the overspeed switch and then connect wires from the speed switch to the 2301 Governor. The overspeed switch can be installed close to the 2301 Governor if needed.

To reset overspeed switch, push in reset button for a moment.

Time Delay Relay

On/Off Time Delay (Relay)

ON/OFF TIME DELAY (RELAY)

Performance Check

A. Items Required For Check:

1. Battery or any D.C. 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 3 (-) 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 from 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 Gauges

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 the chart.

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 the chart.

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

Electric Gauges

1. Put the gauge in position with the letters horizontal and the face 30° back from vertical.

WIRING DIAGRAM FOR TEST
1. Terminal (for test voltage). 2. Test resistance.

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

3. Let the gauge heat at the middle resistance for 5 minutes, then check the pointer position for all of the resistances given.

Mechanical Gauges For Temperature

To check these gauges, put the bulb of the gauge 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 gauge.

DIRECT READING GAUGE

Mechanical Gauges For Oil Pressure

To check these gauges connect the gauge to a pressure source that can be measured with accuracy. Make a comparison of pressure on the gauge of test equipment with the pressures on the direct reading gauge.

DIRECT READING GAUGE

Power Take-Off Clutches

Clutch Adjustment

Check for the correct clutch engagement force. The clutch engagement force can be measured by two methods.

1. Disconnect linkage (if so equipped) from the clutch lever.

2. Check clutch engagement force.

A. 3N7841 and 5N3334:

Fasten a spring scale to the clutch lever at the distance, from the shaft center, shown in the chart.

B. 2W4908:

Use a torque wrench on the splined shaft or hex shape on lever.

3. If the force needed to engage the clutch is not correct, make an adjustment as follows:

4. Remove the inspection plate from the clutch housing.

5. Turn the clutch until lock pin (1) can be seen.

6. Release lock pin (1). Turn the adjustment ring and check the pull needed to engage the clutch again.

CLUTCH ADJUSTMENT
1. Lock pin (push type). 2. Lock pin (pull type).

NOTE: Turn the adjustment ring clockwise, as seen from the rear of the clutch, to increase the pull needed. Turn it counterclockwise to decrease the pull needed.