Table 4-2. Troubleshooting
TEST OR INSPECTION
1. ENGINE FAILS TO TURN OVER WHEN STARTING BUTTON IS DEPRESSED.
Step 1. Check to see if battery disconnect switch is on.
Turn battery switch on.
Step 2. Inspect for loose or broken battery cables.
Tighten or replace broken battery cables.
Step 3. Check for a weak or dead battery.
a. Check the batteries with a hydrometer. Fully charged batteries shall have a minimum specific gravity of 1.275 at
75 F (23.89C).
Constant-current battery charging is always preferred. If you must use a constant-
potential charger, battery temperatures must be maintained at less than 130F (54.44C) by
interrupting the charging procedure as this temperature is approached.
b. If the specific gravity of the electrolyte is less than 1.250, the batteries must be charged before use. Remove the
caps and check the electrolyte level in each cell. If any are low, fill with distilled water or good grade drinking water
(excluding mineral water).
c. A battery charging receptacle is located at the lower left rear of the engine housing. Connect battery charger in
to this receptacle. When you charge the batteries, use a constant current charger.
Check the specific gravity of the electrolyte every 30 minutes. The batteries are fully charged when you get a
constant specific gravity reading for three 30 minute intervals.
d. During charging, check the electrolyte level frequently. Add distilled water when necessary to maintain the
battery electrolyte level. Continue charging after adding distilled water to ensure proper mixing of the solution.
Military batteries and maintenance free batteries cannot be mixed. Undercharge or
overcharge of one will result.
e. If the battery fails to take or maintain a charge replace it.
Step 4. Check for a faulty starter push button switch.
a. Check the starter push button switch for a cracked case, lack of positive switch action, and other damage.
c. Disconnect the electrical leads from the starter push button switch. Remove nut from switch and remove switch
from the control panel.
d. Insert a new starter push button switch in the control panel and secure with nut. Connect all electrical leads.
Step 5. Check for a defective starting motor.
a. Disconnect the electrical leads to the starter solenoid switch.
b. Remove three capscrews and lock washers that secure the starting motor to the flywheel housing.
Pull straight forward on the starting motor and remove it from the engine.
c. Check the armature for free rotation by turning with hand. There must be no catching, binding, or scraping as
the armature is rotated.
d. To check the starter solenoid, apply 24 vdc between the BAT terminal of the solenoid and the switch(s) terminal.
This will advance the starter drive to the engage position. With the drive advanced and power still applied, using a
multimeter check continuity between the BAT and motor (m) terminals. continuity must exist. Break the circuit to
the terminals. The drive must retract fully, and the circuit between the (BAT) and motor (m) terminals must break.
e. Replace a damaged, worn, or inoperative starter.
f. Place starter on the flywheel housing and secure with capscrews and lockwasher. Connect all electrical leads.
2. ENGINE TURNS OVER BUT FAILS TO START (NO SPARK OR WEAK SPARK).
Step 1. Check for a defective ignition switch.
a. Check the ignition switch for a cracked case, lack of positive switch action, and other damage.
c. Disconnect the electrical leads from the switch. Remove nut from switch and remove switch from control panel.
d. Install switch in the control panel and secure with nut. Connect all electrical leads.
Step 2. Check overspeed governor reset.
a. Reset by pushing reset button on top of engine overspeed governor.
b. If the engine starts, and the tachometer indicates over 2750 rpm, stop the engine and adjust the overspeed
governor. If the engine stopped before the tachometer indicated 2650 rpm, you must adjust the overspeed
c. Restart the engine and have an assistant watch the tachometer. To adjust the engine overspeed governor,
loosen the lockscrew that secures the cap in position. To decrease the engine shutoff speed, rotate the cap
clockwise. To raise the engine shutoff speed, turn the cap counterclockwise. After the desired speed 2750 rpm is
obtained, tighten the lock screw. Replace the overspeed governor if it cannot be adjusted.
d. Disconnect and tag the electrical leads. Remove capscrew that secures the overspeed governor to governor
arm and remove the overspeed governor.
e. Install overspeed governor on the governor arm and secure with capscrew. Connect all electrical leads.
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