Harley Davidson 1986-2003 XL/XLH Sportster. Service Manual — page 5

3. Insert the spark plug (Figure 2), or spark tester (Figure
3), into its plug cap and ground the spark plug base against
the cylinder head. Position the spark plug so the electrode is
visible.

WARNING

Mount the spark plug, or tester, away from the
spark plug hole in the cylinder so the spark
plug or tester cannot ignite the gasoline va-
pors in the cylinder. If the engine is flooded,

do not perform this test. The firing of the
spark plug can ignite fuel ejected through the
spark plug hole.

NOTE

If a spark plug is used, perform this test with a
new spark plug.

4. Turn the ignition switch on.

WARNING

Do not hold the spark plug, wire or connector,
or a serious electrical shock may result.

5. Turn the engine over. A crisp blue spark should be evi-
dent across the spark plug electrode or spark tester termi-
nals.
6. If the spark is good, check for one or more of the follow-
ing possible malfunctions:

a. Obstructed fuel line or fuel filter.
b. Low compression or engine damage.
c. Flooded engine.
d. Incorrect ignition timing.

NOTE

If the engine backfires during starting, the ig-
nition timing may be incorrect due to a defec-
tive ignition component. Refer to

Ignition

Timing Adjustment

in Chapter Three for

more information.

7. If the spark is weak or if there is no spark, refer to

En-

gine is Difficult to Start

in this section.

Engine is Difficult to Start

Check for one or more of the following possible malfunc-

tions:
1. Fouled spark plug(s).
2. Improperly adjusted enrichment valve.
3. Intake manifold air leak.
4. A plugged fuel tank filler cap.
5. Clogged fuel line.
6. Contaminated fuel system.
7. An improperly adjusted carburetor.
8. A defective ignition module.
9. A defective ignition coil.
10. Damaged ignition coil primary and/or secondary
wires.
11. Incorrect ignition timing.
12. Low engine compression.
13. Incorrect engine oil viscocity.
14. Discharged battery.
15. A defective starter.
16. Loose or corroded starter and/or battery cables.
17. A loose ignition sensor and module electrical connector.
18. Incorrect pushrod length (intake and exhaust valve
pushrods interchanged).

TROUBLESHOOTING

33

2

1

2

3

Engine Will Not Crank

Check for one or more of the following possible malfunc-

tions:
1. Ignition switch turned off.
2. A faulty ignition switch.
3. Engine run switch in off position.
4. A defective engine run switch.
5. Loose or corroded starter and battery cables.
6. A discharged or defective battery.
7. A defective starter.
8. A defective starter solenoid.
9. A defective starter shaft pinion gear.
10. Slipping overrunning clutch assembly.
11. A seized piston(s).
12. Seized crankshaft bearings.
13. A broken connecting rod.

ENGINE PERFORMANCE

The following check lists assume the engine runs, but is

not operating at peak performance. Refer to the following
procedure(s) that best describes the symptom(s).

Spark Plugs Fouled

If the spark plugs continually foul, check for the follow-

ing:
1. Severely contaminated air filter element.
2. Incorrect spark plug heat range.
3. Rich fuel mixture.
4. Worn or damaged piston rings.
5. Worn or damaged valve guide oil seals.
6. Excessive valve stem-to-guide clearance.
7. Incorrect carburetor float level.

Engine Runs But Misfires

1. Fouled or improperly gapped spark plugs.
2. Damaged spark plug cables.
3. Incorrect ignition timing.
4. Defective ignition components.
5. An obstructed fuel line or fuel shutoff valve.
6. Obstructed fuel filter.
7. Clogged carburetor jets.
8. Loose battery connection.
9. Wiring or connector damage.
10. Water or other contaminates in the fuel.
11. Weak or damaged valve springs.
12. Incorrect camshaft/valve timing.
13. Damaged valve(s).
14. Dirty electrical connections.
15. Intake manifold or carburetor air leak.
16. A plugged carburetor vent hose.
17. Plugged fuel tank vent system.

Engine Overheating

1. Incorrect carburetor adjustment or jet selection.
2. Incorrect ignition timing or defective ignition system
components.
3. Improper spark plug heat range.
4. Low oil level.
5. Oil not circulating properly.
6. Leaking valves.
7. Heavy engine carbon deposits.

Engine Runs Rough with Excessive Exhaust Smoke

1. Clogged air filter element.
2. Rich carburetor adjustment.
3. Choke not operating correctly.
4. Water or other fuel contaminants.
5. Clogged fuel line and/or filter.
6. Spark plug(s) fouled.
7. Defective ignition components or wiring.
8. Short circuits from damaged wire insulation.
9. Loose battery cable connections.
10. Incorrect camshaft/valve timing.
11. Intake manifold or air filter air leak (carbureted models).

Engine Loses Power

1. Incorrect carburetor adjustment.
2. Engine overheating.
3. Incorrect ignition timing.
4. Incorrectly gapped spark plugs.
5. An obstructed muffler(s).
6. Dragging brake(s).

Engine Lacks Acceleration

1. Incorrect carburetor adjustment.

34

CHAPTER TWO

4

Battery terminal

Starter/field wire
terminal

Solenoid

Field
wire

Starter

Relay
terminal

2. Clogged fuel line.

3. Incorrect ignition timing.

4. Dragging brake(s).

Valve Train Noise

1. A bent pushrod(s).

2. A defective hydraulic lifter(s).

3. A bent valve(s).

4. Rocker arm seizure or damage (binding on shaft).

5. Worn or damaged camshaft gear bushing(s).

6. Worn or damaged camshaft gear(s).

7. Worn or damaged camshaft drive chain(s).

ELECTRICAL COMPONENT REPLACEMENT

Most dealerships and suppliers will not accept the return

of any electrical part. Consider and test results carefully be-
fore replacing a component that tests only slightly out of
specification.

STARTING SYSTEM

The starting system consists of the battery, starter, starter

relay, solenoid, start button, starter mechanism and related
wiring.

When the ignition switch is turned on and the start button

is pushed in, current is transmitted from the battery to the
starter relay. When the relay is activated, it activates the
starter solenoid that mechanically engages the starter with
the engine.

Starting system problems are most often related to a loose

or corroded electrical connection.

Refer to Figure 4 for starter and solenoid terminal identi-

fication.

Troubleshooting Preparation

Before troubleshooting the starting system, check for the

following:
1. The battery is fully charged.
2. Battery cables are the proper size and length. Replace
damaged or undersized cables.
3. All electrical connections are clean and tight. High re-
sistance caused from dirty or loose connectors can affect
voltage and current levels.
4. The wiring harness is in good condition, with no worn or
frayed insulation or loose harness sockets.
5. The fuel tank is filled with an adequate supply of fresh
gasoline.
6. The spark plugs are in good condition and properly gap-
ped.
7. The ignition system is working correctly.

Voltage Drop Test

Before performing the steps listed in

Starter Testing

in

this section, perform this voltage drop test. These steps
check the entire starting circuit to find weak or damaged
electrical components that may be causing the starting
system problem. A voltmeter is required to test voltage
drop.
1. To check voltage drop in the solenoid circuit, connect
the positive voltmeter lead to the positive battery terminal.
Connect the negative voltmeter lead to the solenoid termi-
nal (Figure 5).
2. Turn the ignition switch on and push the starter button
while reading the voltmeter scale. Note the following:

a. The circuit is operating correctly if the voltmeter

reading is 1 volt or less. A voltmeter reading of 12
volts indicates an open circuit.

b. A voltage drop of more than 1 volt indicates a prob-

lem in the solenoid circuit.

c. If the voltage drop reading is correct, continue with

Step 3.

TROUBLESHOOTING

35

2

5

Start switch

Relay

Ignition circuit

breaker

Ignition switch

Main circuit

breaker

Battery

Solenoid

Starter

0.1 amp

20 amp

0.1 amp

150 amp

VOM

150 amp

NOTE

Steps 3 and 4 check the voltage drop across
the starter ground circuit. To check any
ground circuit in the starting circuit, repeat
this test and leave the negative voltmeter
lead connected to the battery and connect
the positive voltmeter lead to the ground in
question.

3. To check the starter ground circuit, connect the negative
voltmeter lead to the negative battery terminal. Connect the
positive voltmeter lead to the starter housing (Figure 6).
4. Turn the ignition switch on and push the starter button
while reading the voltmeter scale. The voltage drop must
not exceed 0.2 volts. If it does, check the ground connec-
tions between the meter leads.
5. If the problem is not found, refer to

Starter Testing

in

this section.

Starter Testing

CAUTION

Never operate the starter for more than 30
seconds at a time. Allow the starter to cool
before reusing it. Failing to allow the starter
to cool after continuous starting attempts can
damage the starter.

The basic starter-related troubles are:

1. Starter does not spin.
2. Starter spins but does not engage.
3. The starter will not disengage after the start button is re-
leased.
4. Loud grinding noises when starter turns.
5. Starter stalls or spins too slowly.

Starter does not spin

1. Turn the ignition switch on and push the starter button
while listening for a click at the starter relay in the electrical
panel. Turn the ignition switch off and note the following:

a. If the starter relay clicks, test the starter relay as de-

scribed in this section. If the starter relay test readings
are correct, continue with Step 2.

b. If the solenoid clicks, go to Step 3.
c. If there was no click, go to Step 5.

2. Check the wiring connectors between the starter relay
and solenoid. Note the following:

a. Repair any dirty, loose fitting or damaged connectors

or wiring.

b. If the wiring is in good condition, remove the starter

as described in Chapter Twelve. Perform the solenoid
and starter current draw bench tests described in this
section.

3. Perform a voltage drop test between the battery and so-
lenoid terminals as described in this section. The normal
voltage drop is less than 1 volt. Note the following:

a. If the voltage drop is less than 1 volt, perform Step 4.

b. If the voltage drop is more than 1 volt , check the so-

lenoid and battery wires and connections for dirty or
loose fitting terminals; clean and repair as required.

36

CHAPTER TWO

6

Starter switch

Relay

Ignition circuit

breaker

Ignition switch

Main circuit

breaker

Battery

Solenoid

Starter

0.1 amp

0.1 amp

20 amp

150 amp

150 amp

VOM

7

Battery

50 terminal

C terminal

b. Load the battery at 50% of the cold cranking amper-

age (CCA) or 100 amperes.

c. After 15 seconds, the voltage reading with the load still

applied must be 9.6 volts or higher at 70

°

F (21

°

C).

Now quickly remove the load and turn the tester off.

4. If the voltage reading was 9.6 volts or higher, the battery
output capacity is good. If the reading was below 9.6 volts,
the battery is defective.
5. With the tester off, disconnect the cables from the bat-
tery.
6. Install the battery as described in this section.

CHARGING SYSTEM

The charging system consists of the battery, alternator

and a voltage regulator/rectifier. Refer to Figure 20 or Fig-
ure 21. Alternating current generated by the alternator is
rectified to direct current. The voltage regulator maintains
the voltage to the battery and additional electrical loads,
such as the lights and ignition system, at a constant voltage
regardless of variations in engine speed and load.

A malfunction in the charging system generally causes the

battery to remain undercharged. To prevent damage to the al-
ternator and the regulator/rectifier when testing and repair-
ing the charging system, note the following precautions:
1. Always disconnect the negative battery cable, as de-
scribed in this chapter, before removing a component from
the charging system.
2. To charge the battery, remove the battery from the mo-
torcycle and recharge it as described in this chapter.
3. Inspect the battery case (Figure 18). Look for bulges or
cracks in the case, leaking electrolyte or corrosion build-up.
4. Check the charging system wiring for signs of chafing,
deterioration or other damage. Refer to the appropriate wir-
ing diagram at the end of this manual.
5. Check the wiring for corroded or loose connections.
Clean, tighten or reconnect wiring as required.

Battery Current Draw Test

This test measures the current draw, or drain, on the bat-

tery when all electrical systems and accessories are off. Per-
form this test if the battery will not hold a charge when the
motorcycle is not being used. Maximum current draw
should be less than 3.0 mA. The battery must be fully
charged to perform this test.
1. Disconnect the negative battery cable as described in
this chapter.
2. Connect an ammeter between the negative battery cable
end and the negative battery terminal as shown in Figure 22.
3. With the ignition switch, lights and all accessories
turned off, read the ammeter. If the current drain exceeds
3.0 mA, continue with Step 4.
4. Refer to the appropriate wiring diagram at the end of this
manual. Check the charging system wires and connectors
for shorts or other damage.

402

CHAPTER TWELVE

20

CHARGING SYSTEM

(1986-1990 MODELS)

1. Clutch housing
2. Screw
3. Stator
4. Bolts
5. Lockwasher
6. Washer
7. Locknut
8. Voltage regulator

21

CHARGING SYSTEM

(1991-2003 MODELS)

1. Rotor
2. Stator
3. Torx screw
4. Bolt
5. Bolt
6. Voltage regulator

5. Unplug each electrical connector separately and check
for a reduction in the current draw. If the meter reading
changes after a connector is disconnected, the source of the
current draw has been found. Check the electrical connec-
tors carefully before testing the individual component.
6. After completing the test, disconnect the ammeter and
reconnect the negative battery cable.

Testing

A malfunction in the charging system generally causes

the battery to remain undercharged. Perform the following
visual inspection to determine the cause of the problem. If

the visual inspection proves satisfactory, test the charging
system as described in

Charging System

in Chapter Two.

1. Make sure the battery cables are connected properly. If
polarity is reversed, check for a damaged voltage regula-
tor/rectifier.
2. Inspect the terminals for loose or corroded connections.
Tighten or clean them as required.
3. Inspect the battery case. Look for bulges or cracks in the
case, leaking electrolyte or corrosion buildup.
4. Check all connections at the alternator to make sure they
are clean and tight.
5. Check the circuit wiring for corroded or loose connec-
tions. Clean, tighten or connect wiring as required.

ALTERNATOR

(1986-1990 MODELS)

The alternator rotor and stator on 1986-1990 models are

located behind the clutch.

Rotor Removal/Installation

Refer to Figure 20.

1. Remove the clutch as described in Chapter Six.

NOTE

Do not disassemble the clutch assembly.

2. Turn the clutch assembly upside down and place it on
the workbench.

NOTE

Because a portion of the clutch shell operates
as the alternator rotor, removal of the clutch
shell may prove difficult due to the magnetic
pull of the rotor magnets.

3. Remove the rotor circlip (Figure 23). Then remove the
rotor/clutch shell assembly (Figure 24) from the clutch
hub.
4. If necessary, replace the rotor/clutch shell as a single
unit.

CAUTION

Inspect the inside of the rotor for small bolts,
washers or other metal debris that may have
been picked up by the magnets. These small
metal bits can cause severe damage to the al-
ternator stator assembly.

5. Reassemble the new rotor/clutch shell assembly. Secure
it with a new circlip (Figure 23).
6. Install the clutch as described in Chapter Six.

Stator Removal/Installation

A T-27 Torx socket is required for this procedure.

ELECTRICAL SYSTEM

403

12

22

Ammeter

Battery
ground
cable

23

24

1. Disconnect the stator electrical connector below the
crankcase on the left side.
2. Remove the clutch as described in Chapter Six.

NOTE

Do not disassemble the clutch.

3. Remove the four Torx screws securing the stator (Fig-
ure 25) to the transmission access cover. Discard the Torx
screws.
4. Remove the stator by prying the stator wire grommet
(Figure 26) out of the crankcase and remove the wire/con-
nector together with the stator. Note the pate of the wire
through the crankcase and the to the connector of the wiring
harness.
5. Installation is the reverse of these steps, noting the fol-
lowing:

a. When routing the new stator wire and connector,

route it between the frame and rear engine gap. Press
the grommet fully into the crankcase opening.

CAUTION

Use new Torx screws. The thread locking
compound originally applied to the Torx
screws is sufficient for one-time use only. A
loose Torx screw could back out and cause al-
ternator damage.

b. Install new Torx screws and tighten to 30-40 in.-lb.

(3-4.5 N•m).

c. Install the clutch assembly as described in Chapter

Six.

Voltage Regulator
Removal/Installation

The voltage regulator is mounted on the front frame

downtubes (Figure 27).

The voltage regulator must be serviced as a unit assem-

bly. It cannot be rebuilt.
1. Remove the seat (Chapter Seventeen).
2. Disconnect the voltage regulator wiring connector be-
low the crankcase on the left side.
3. Remove any wiring retaining straps.
4. Disconnect the voltage regulator connector from the
main circuit breaker.
5. Remove the voltage regulator mounting screws and re-
move the voltage regulator (Figure 27).
6. Reverse the removal steps to install the voltage regulator.

ALTERNATOR

(1991-2003 MODELS)

The alternator rotor and stator on 1991-2003 models are

located behind the engine sprocket.

404

CHAPTER TWELVE

25

26

27

28