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Harley Davidson Softail Delux FLSTN BIKE 2011-2015. Service Manual - page 18

Table 3-22. Cylinder Bore (Twin Cam 103)

REPLACE IF WEAR EXCEEDS

ITEM

98.48

3.877

Standard

98.60

3.882

0.005 in oversize

98.73

3.887

0.010 in oversize

Table 3-23. Piston

REPLACE IF WEAR

EXCEEDS

PISTON

0.076

0.003

Fit in cylinder (loose)

0.020

0.0008

Piston pin fit (loose)

0.762

0.030

Top compression

Ring end
gap

0.864

0.034

2nd compression

1.27

0.050

Oil control rails

0.114

0.0045

Top compression

Ring side
clearance

0.114

0.0045

2nd compression

0.254

0.010

Oil control rails

Table 3-24. Connecting Rod

REPLACE IF WEAR

EXCEEDS

CONNECTING ROD

0.051

0.002

Piston pin fit (loose)

0.051

0.002

Fit on crankpin (loose)

Table 3-25. Breather Assembly

REPLACE IF WEAR

EXCEEDS

BREATHER ASSEMBLY

0.13

0.005

Breather cover warpage

0.13

0.005

Breather baffle warpage

Table 3-26. Valve Stem to Guide

REPLACE IF WEAR EXCEEDS

VALVE STEM TO GUIDE

0.0965

0.0038

Intake

0.0965

0.0038

Exhaust

Table 3-27. Flywheel

REPLACE IF WEAR EXCEEDS

FLYWHEEL

0.305

0.012

Runout (shaft measured
in case)

0.127

0.005

Runout (measured in
truing stand)

0.330

0.013

End play

Table 3-28. Crankshaft Roller Bearing

REPLACE IF

CRANKSHAFT ROLLER
BEARING

More than 0.038

More than

0.0015

Roller bearing fit (loose)

Less than 0.097

Less than

0.0038

Bearing fit in crankcase
(tight)

Less than 0.010

Less than

0.0004

Inner race on crankshaft
(tight)

Table 3-29. Counterbalancer

REPLACE IF WEAR

EXCEEDS

COUNTERBALANCER

0.203

0.008

Sprocket flatness

2.03

0.080

Tensioner guide grooving
(max)

47.0

1.85

Tensioner spring length (min)

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3-6 2013 Softail Service: Engine

3.4

ENGINE OIL FLOW

OIL FEED

See

Figure 3-1

. Oil flows from the oil tank feed line (1) to the

engine feed connection (2) at the rear right side of the crank-
case.

sm02782a

1. Oil tank feed line
2. Feed connection on engine
3. Return line
4. Vent line
5. Oil tank

Figure 3-1. Oil Flow from Tank

See

Figure 3-2

. Running through a passageway in the crank-

case (1), oil exits a hole in the crankcase and then enters a
hole in the cam support plate (2). Passing through a channel
in the cam support plate, oil enters the feed side of the oil pump
(3). See

3.5 OIL PUMP OPERATION

. The feed gerotors of the

pump direct the flow up a second channel in the cam support
plate.

A passage (5) connects to a pressure relief valve (6) mounted
in the bypass port of the cam support plate. When the oil
pressure exceeds the setting of the valve spring (35 psi
(241kPa)), the orifice opens to bypass (7) excess oil back to
the feed side of the pump (3).

See

Figure 3-3

. Oil not returned to the feed side exits the cam

support plate and passes through a hole in the crankcase.
Flowing through a passageway in the crankcase, the oil exits
the lower hole in the oil filter mount. The oil pressure sending
unit (8) also reads the pressure within that passageway.

sm02783

1. Crankcase passage
2. Cam support plate/crankcase connection
3. Feed side of oil pump
4. Oil pump output
5. Overflow passage
6. Pressure relief valve
7. Bypass passage
8. Oil pressure sending unit
9. Return from oil filter into cam support plate
10. Feed to chain guide bracket

Figure 3-2. Cam Support Plate Oil Flow

sm02784

Figure 3-3. Oil Filter Flow

See

Figure 3-2

. After circulating through the oil filter, oil is dir-

ected back into the crankcase through the spigot in the oil filter
mount. Exiting through a passageway in the crankcase, oil
reenters the cam support plate (9).

Filtered oil is then routed to the top and bottom ends of the
engine. See

3.4 ENGINE OIL FLOW, Top End

3.4 ENGINE

OIL FLOW, Bottom End

and

3.4 ENGINE OIL FLOW, Chain

Guide Bracket

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2013 Softail Service: Engine 3-7

TOP END

Two illustrations accompany this explanation.

•

Cam support plate oil flow is shown in

Figure 3-4

•

Top end oil flow is shown in

Figure 3-5

Oil passes through a channel in the cam support plate. It exits
on the crankcase side through two holes near the top (A11,
A12). Oil enters two holes in the crankcase flange (B13, B14).
One passage leads to the front cylinder and the other to the
rear cylinder. Oil then travels through passageways in the
crankcase to the hydraulic lifter bores (D15).

Oil enters each lifter bore through oblong holes (E16), flows
around the lifter and enters a hole at the side of the lifter body.
As the chamber inside the lifter body is filled, the pushrod
socket rises to eliminate lash of the valve train components.
Oil then exits a hole centered in the lifter socket and flows up
the hollow pushrods.

NOTE

An additional round hole (E17) drilled into the lifter bores feed
oil to the piston jets.

Exiting holes at the top of the pushrods, oil enters the rocker
arms lubricating the rocker arm bushings. Oil flows along the
rocker arm shafts and exits a pin hole in the outboard side of
each rocker arm (F18). This oil lubricates the valve springs
and the top of the valve stem.

Oil runs to the low side of the rocker housing and enters the
exhaust valve spring pocket. A drain hole (G19) leads to a
passageway in the cylinder head casting.

Oil exits the bottom of the cylinder head and passes through
a dowel pin (H20) on the cylinder flange. Oil flows through a
vertical passageway in the cylinder. It then passes through a
second dowel pin on the cylinder deck (I21) and enters the left
crankcase half.

Flowing through a horizontal passageway in the left crankcase
half (J22), oil runs through a third dowel pin (K23) to the right
crankcase half. Finally it travels through another passageway
before emptying into the cam compartment (B23, B24).

Oil collecting in the cam compartment is picked up by one of
two scavenge lobes on the oil pump (B25).

sm02373

Figure 3-4. Engine Oil Flow: Cam Support Plate/Right

Crankcase Half

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3-8 2013 Softail Service: Engine

sm02785

Figure 3-5. Engine Oil Flow: Top End

BOTTOM END

Three illustrations accompany this explanation.

•

Cam support plate oil flow is shown in

Figure 3-4

•

Top end oil flow is shown in

Figure 3-5

•

Bottom end oil flow is shown in

Figure 3-6

Oil traveling through the horizontal passage (A11-A12) at the
top of the cam support plate (en route to the cylinders) also
passes through a hole at the top of each camshaft bore. This
oil lubricates the journals of the plain bearing cams. Some oil

flowing to the rear cylinder sprays through a pin hole to lubricate
the secondary cam chain.

Oil to the rear cylinder also travels down the vertical passage
(A27) at the rear of the cam support plate. This oil exits a hole
on the outboard side to supply oil to the primary cam chain
tensioner (A28).

The flow of oil in the vertical passage (A29) at the center of
the cam support plate passes through a hole on the inboard
side. This supplies oil to the secondary cam chain tensioner.
Oil also sprays through a pin hole (A30) to lubricate the primary
cam chain. Oil then flows through a hole in the crankshaft
bushing where it enters a passage in the crankshaft (L27).

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2013 Softail Service: Engine 3-9

Oil flows through the center of the crankshaft and through a
cross passage into the right side of the flywheel. Oil enters the
crank pin and exits through three holes to lubricate the lower
rod bearing set.

Oil splash and mist created by flywheel rotation lubricates the
crankshaft and the camshaft bearings in the right crankcase
half. This same action serves to lubricate the sprocket shaft
bearing in the left crankcase half (M28).

Since the oil mist also lubricates the cylinder walls, three holes
on each side of the piston (in the area of the third ring land)
evacuate excess oil scraped from the walls on the piston
downstroke.

The piston jets (N29) receive oil from the intake lifter bores.
They spray the underside of the piston for cooling of the piston

crown and skirt area. A check valve in each jet opens only
when the oil pressure reaches 12-18 PSI (82.7-124.1 kPa), at
which point the engine is operating above idle speed. Oil
pressure at idle speeds will be 9-12 PSI (62.1-82.7). At this
pressure the valve remains closed to prevent over oiling and
to provide proper system operating pressure.

Oil spray from each piston jet also enters a hole at the bottom
of each pin boss (O30) to lubricate the piston pin. The spray
also allows a portion of the oil to reach the upper rod bushing
(D31).

Surplus oil falls back to the bottom of the flywheel compartment
where it collects in the sump area (P32). Oil in the sump is
drawn to the scavenge side of the oil pump (B35) through an
internal channel (P33, C34).

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3-10 2013 Softail Service: Engine

sm02786

Figure 3-6. Engine Oil Flow: Bottom End

CHAIN GUIDE BRACKET

Three illustrations accompany this explanation.

•

Cam support plate oil flow is shown in

Figure 3-4

•

Bottom end oil flow is shown in

Figure 3-6

•

Chain guide bracket oil flow is shown in

Figure 3-7

The flow of oil travels down the vertical passage at the rear of
the cam support plate (A27).

As oil exits the inboard side of the cam support plate, it enters
a crankcase dowel. The hole contains the chain guide screen
and O-ring (Q40).

NOTE

This screen blocks any debris which might enter the chain
guide bracket. The screen has no regular maintenance
schedule. However, clean the screen and replace the O-ring
every time the engine is disassembled.

Oil travels through the right side crankcase (R41) and goes
into the chain guide bracket rubber interconnect (S42). Inside
the chain guide (T43), oil travels to both the front and rear

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2013 Softail Service: Engine 3-11

hydraulic tensioners (T45, T44). The tensioners sit underneath
the front and rear tensioner guides which provide support for

the counterbalancer chain. A small hole at the top of each
tensioner vents any trapped air into the flywheel compartment.

sm02787

Figure 3-7. Engine Oil Flow: Chain Guide Bracket

OIL RETURN

The "dual kidney" designation given to the oil pump refers to
its two scavenging functions, whereby it simultaneously draws
oil from both the cam and flywheel compartments.

Oil sucked up by the scavenge lobes passes through the
scavenge gerotors of the oil pump and is directed through a
return channel (A40) in the cam support plate. See

3.5 OIL

PUMP OPERATION

Exiting a hole on the inboard side of the cam support plate,
the oil enters a hole in the crankcase flange (B41).

The oil flows through a passageway in the crankcase and exits
the upper fitting (3) at the rear right side of the crankcase as
shown in

Figure 3-1

. Passing through a flexible hose, the flow

of oil returns to the oil tank.

A third hose (4) connects the cam compartment with the oil
tank via a third passage in the transmission case. This crank-
case breather connection provides the pressure balance
necessary for oil circulation.

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3-12 2013 Softail Service: Engine

3.5

OIL PUMP OPERATION

GENERAL

See

Figure 3-8

. The oil pump consists of a housing containing

two gerotor gear sets driven by the crankshaft. One is feed
and the other scavenge. The feed gerotor set distributes oil to
the engine. The scavenge gerotor set draws oil from the cam
and flywheel compartments and returns it to the oil pan.

Each gerotor gear set has an inner and outer gerotor. The inner
and outer gerotors have fixed centers that are slightly offset to
one another. Also, the inner gerotor has one less tooth.

sm02292

1. Feed gerotor
2. Scavenge gerotor

Figure 3-8. Oil Pump Gerotors

OPERATION

The oil pump is driven by the crankshaft. The inlet and outlet
sides of the pump are sealed by the tips and lobes of the inner
and outer gerotors. This prevents oil on the outlet side (high
pressure) from being transferred to the inlet side.

sm02317

1. Oil in
2. Seal
3. Outer gerotor
4. Inner gerotor

Figure 3-9. Inlet Side Oil Flow

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2013 Softail Service: Engine 3-13

sm02319

1. Seal
2. Oil out
3. Continuous flow

Figure 3-10. Outlet Side Oil Flow

See

Figure 3-9

. As the gerotors rotate, the cavity volume

increases between the inner and outer gerotors on the inlet
side of the pump. This creates a vacuum causing oil to be
drawn in. The cavity increases until the volume is equivalent
to that of the missing tooth on the inner gerotor.

See

Figure 3-10

. As the oil moves to the outlet side of the

pump, the cavity decreases in volume. This forces pressurized
oil out the discharge port. In operation, the gerotors provide a
continuous flow of oil.

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3-14 2013 Softail Service: Engine

3.6

BREATHER OPERATION

GENERAL

The crankcase breather system relieves crankcase pressure
produced by the downstroke of the pistons. Crankcase vapors
are then directed into the intake air stream to be burned during
normal combustion. Burning crankcase vapors eliminates the
pollutants normally discharged from the crankcase.

See

Figure 3-11

. As pistons push downward, displaced air in

the crankcase is vented through the crankshaft roller bearing
into the cam compartment. The air then flows up the pushrod
covers (1) into the rocker housing. The moving air absorbs a
small amount if oil vapor as it travels through the engine.

The oil/air vapor rushes under the rocker arm support plate
and passes through an opening at the bottom of the plate to
enter the breather baffle compartment (2).

In the baffle compartment, the flow of air passes upward
through the oil filter gauze, where the oil is removed from the
air. Two pin holes in the rocker arm support plate allow the
separated oil to drain back into the crankcase.

Passing through the oil filter gauze, the vapor passes through
the umbrella valve (3) into the breather compartment. The
umbrella valve only allows air to be vented one way.

In the breather compartment, air flows downward through holes
aligned in the breather baffle, rocker arm support plate and
rocker housing. Exiting the rocker housing, air enters a pas-
sageway cast into the top of the cylinder head. Proper orienta-
tion of the rocker housing gasket is critical for effective sealing
of this passageway.

Air flows through the cylinder head passageway and through
a passage in the air cleaner backplate bolt (4). It passes
through a breather tube (5) into the air filter element. It then
joins with the intake air stream and is burned during normal
combustion.

NOTE

Air cleaner mounting without installation of the breather tubes
allows crankcase vapors to be vented into the atmosphere.
This violates legal emissions standards.

sm02323

1. Pushrod cover
2. Breather baffle compartment
3. Umbrella valve
4. Air cleaner backplate bolt
5. Breather tube

Figure 3-11. Breather Air Flow

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2013 Softail Service: Engine 3-15

3.7

OIL PRESSURE

OIL PRESSURE INDICATOR LAMP

See

Figure 3-12

. The red OIL PRESSURE indicator lamp illu-

minates to indicate improper circulation of the engine oil. The
lamp illuminates when the ignition is first turned on (before the
engine is started), but should be extinguished once the engine
is running.

If the oil pressure indicator lamp remains lit, always check
the oil supply first. If the oil supply is normal and the lamp
is still lit, stop the engine at once and do not ride further
until the trouble is located and the necessary repairs are
made. Failure to do so may result in engine damage.
(00157a)

If the indicator lamp does not extinguish, it may be caused by
low oil level or diluted oil supply. In freezing weather, the oil
feed and return lines can clog with ice or sludge. Other condi-
tions that may cause the lamp to remain lit are:

•

Faulty lamp wiring

•

Faulty oil pressure sending unit

•

Damaged oil pump

•

Plugged oil filter element

•

Incorrect oil viscosity for the operating temperature

•

Fractured or weak spring in the oil pressure relief valve

•

Incorrectly installed O-rings in the engine

To troubleshoot the problem, always check the engine oil level
first. If the oil level is OK, determine if oil returns to the oil pan.
If oil does not return, shut off the engine until the problem is
located and corrected.

sm02321

Figure 3-12. Oil Pressure Indicator Lamp

CHECKING OIL PRESSURE

TOOL NAME

PART NUMBER

OIL PRESSURE GAUGE SET

HD-96921-52D

Check operating oil pressure as follows:

Verify engine oil is at the proper level. See

1.6 ENGINE

OIL AND FILTER

See

Figure 3-13

. Remove oil pressure switch from crank-

case. See

7.30 OIL PRESSURE SWITCH

See

Figure 3-14

. Install OIL PRESSURE GAUGE SET

(Part No. HD-96921-52D).

Install adapter (2) in oil pressure switch mounting
hole. Tighten adapter until snug.

Assemble banjo bolt (3), washer (4), oil pressure
gauge (1) banjo fitting and second washer onto
adapter and tighten until snug.

Start engine and allow to reach operating temperature.

NOTE

Engine oil should be at normal operating temperature, 230 °F
(110 °C), for an accurate reading.

Oil pressure should be within specifications. Refer to

Table 3-30

See

3.8 TROUBLESHOOTING

if readings are question-

able.

Stop engine. Remove oil pressure gauge assembly.

Install oil pressure switch. See

7.30 OIL PRESSURE

SWITCH

Table 3-30. Oil Pressure

SPECIFICATION *

CHECK

METRIC

SAE

34.5 kPa

5 psi

Oil pressure - min at idle

207-262 kPa

30-38 psi

Oil pressure - normal at
2000 rpm

345 kPa

50 psi

Oil pressure - max

* With oil at normal operating temperature of 230 °F (110 °C)

sm02293

Figure 3-13. Oil Pressure Switch

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3-16 2013 Softail Service: Engine

sm02322

1. Gauge
2. Adapter
3. Banjo bolt
4. Washer (2)

Figure 3-14. Oil Pressure Gauge Set

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2013 Softail Service: Engine 3-17

3.8

TROUBLESHOOTING

DIAGNOSING VALVE TRAIN NOISE

To diagnose and correct noisy hydraulic lifters and valve train
components, use the following procedures:

With engine and oil at normal operating temperature, check
oil pressure at 2000 rpm. If oil pressure is above 50 psi
(345 kPa) or below 5 psi (34 kPa), inspect the following
for restrictions or blockage:

Oil pump

Crankcase passages

Oil hoses

Repair or replace parts as necessary.

If oil is not reaching the hydraulic lifters, remove and
inspect. See

3.19 PUSHRODS, LIFTERS AND COVERS,

Lifter Inspection

. Clean lifter bore of all foreign material.

Replace hydraulic lifter if required.

Inspect pushrod, lifter and lifter block for proper fit and
unusual wear. Replace parts as necessary.

Visually inspect camshaft lobes for abnormal wear.

Check cam chain tensioning shoe for wear.

Remove cylinder head and rocker box assemblies. Check
rocker arm end play and check for binding. Inspect valve
stems for scuffing and check stem to guide clearance.
Check valve seats for signs of looseness or shifting.

Grind valves and valve seats. See

3.20 CYLINDER HEAD,

Valve and Seat Refacing

COMPRESSION TEST

TOOL NAME

PART NUMBER

CYLINDER COMPRESSION GAUGE

HD-33223-1

TORQUE VALUE

FASTENER

16.3-24.4 Nm

12-18 ft-lbs

Spark plug

A compression test can help determine the source of cylinder
leakage. Use CYLINDER COMPRESSION GAUGE (Part
No. HD-33223-1) with a screw-in type adapter.

NOTE

All twin cam engines use a 12 mm adapter with the compres-
sion gauge.

Operate engine to normal operating temperature.

Disconnect spark plug wires, clean around plug base and
remove plugs.

Remove air cleaner. See

4.3 AIR CLEANER ASSEMBLY

Connect compression tester to front cylinder per manufac-
turer's instructions.

Make sure transmission is in neutral. Hold throttle at wide
open throttle position and crank engine continuously
through 5 to 7 full compression strokes and note gauge

readings at the end of the first and last compression
strokes. Record test results.

Repeat test on rear cylinder.

NOTE

Verify throttle is closed before assembling air cleaner.

Assemble the air cleaner. See

4.3 AIR CLEANER

ASSEMBLY

If the final readings are a minimum of 125 psi (862 kPa)
and do not indicate more than a 10% variance between
cylinders, compression is considered normal. If compres-
sion does not meet specifications, refer to

Table 3-31

for

possible causes.

If readings do not meet specifications, inject approximately
1/2 oz. (15 ml) engine oil into each cylinder and repeat
the compression tests on both cylinders. Readings that
are considerably higher during the second test indicate
worn piston rings.

10. Install the spark plugs and tighten to 12-18 ft-lbs (16.3-

24.4 Nm). Connect spark plug wires.

Table 3-31. Compression Test Results

TEST RESULTS

DIAGNOSIS

Compression low on first stroke, tends to
build up on the following strokes, but does
not reach normal. Improves considerably
when oil is added to cylinder.

Ring trouble

Compression low on first stroke, does not
build up much on following strokes. Does
not improve considerably with the addition
of oil. Check for correct pushrod length.

Valve trouble

Same reaction as valve trouble.

Head gasket
leak

CYLINDER LEAKDOWN TEST

TOOL NAME

PART NUMBER

CYLINDER LEAKDOWN TESTER

HD-35667-A

NOTE

On vehicles with automatic compression release (ACR), verify
the ACRs are closed for this test. Perform the test with the
ignition/light switch in the OFF position.

The cylinder leakdown test will help pinpoint leaking valves,
worn, damaged or stuck piston rings and blown head gaskets.
The cylinder leakage tester applies compressed air to the cyl-
inder at a controlled pressure and volume. It then measures
the percent of leakage from the cylinder.

Use the CYLINDER LEAKDOWN TESTER (Part No. HD-
35667-A). Follow the specific instructions supplied with the
tester.

The following are some general instructions that apply to
Harley-Davidson V-twin engines:

Run engine until it reaches normal operating temperature.

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3-18 2013 Softail Service: Engine

Stop engine. Clean dirt from around spark plugs. Remove
the spark plugs.

Rotate crankshaft until piston in the cylinder being tested
is at top dead center of compression stroke (both valves
closed) during the test.

To keep the engine from turning over when air pressure
is applied to the cylinder, engage transmission in highest
gear and lock the rear brake.

NOTE

Before performing the cylinder leakdown test, verify the tester
itself is free from leakage. Apply a soap solution around all
tester fittings. Connect cylinder leakdown tester to compressed
air source. Look for any bubbles that indicate leakage from the
tester.

Following the manufacturer's instructions, perform a cyl-
inder leakdown test on the front cylinder. Make a note of
the percent of leakage. Leakage greater than 10% indic-
ates internal engine problems.

Listen for air leaks at throttle body, exhaust pipe and head
gasket. Air escaping through the throttle body indicates a
leaking intake valve. Air escaping through the exhaust
pipe indicates a leaking exhaust valve.

NOTE

If air is escaping through valves, verify that piston is still at TDC
or check for correct pushrod length.

Repeat procedure on rear cylinder.

DIAGNOSING SMOKING ENGINE OR HIGH
OIL CONSUMPTION

Perform both a compression test and a cylinder leakage test.
See

3.8 TROUBLESHOOTING, Compression Test

and

3.8 TROUBLESHOOTING, Cylinder Leakdown Test

. If further

testing is needed, remove suspect head(s) and inspect for the
following:

Check Prior To Cylinder Head Removal

Oil level overfull.

Oil carryover.

Breather hose restricted.

Restricted oil filter.

Check After Cylinder Head Removal

Oil return passages for clogging.

Valve guide seals.

Valve guide to valve stem clearance.

Gasket surface of both head and cylinder.

Cylinder head casting's porosity allowing oil to drain into
combustion chamber.

O-ring damaged or missing from oil pump/crankcase
junction.

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2013 Softail Service: Engine 3-19

3.9

HOW TO USE THIS SECTION

TOP END REPAIR

NOTE

During top end disassembly, the engine may be left in the
chassis for service.

If servicing only cylinder head components, pistons, cylinders
and/or upper rod bushings, two options are available depending
upon engine status.

•

3.10 TOP END SERVICE, Engine in Chassis

•

3.10 TOP END SERVICE, Engine Removed from Chassis

BOTTOM END REPAIR

NOTE

Servicing components in the cam compartment requires only
partial disassembly. This can be done with the engine left in
the chassis.

After disassembling as far as the cylinder heads you may find
that bottom end repair is necessary. Bottom end service may
require either partial or complete disassembly of the engine.

•

To service the cam compartment, see

3.24 CAM COM-

PARTMENT AND COMPONENTS

•

To service components in the flywheel compartment, the
engine must be removed and the crankcase halves split.

See

3.11 CAM COMPARTMENT SERVICE, Engine

Removed From Chassis

TYPICAL SYMPTOMS

Symptoms indicating a need for engine repair are often mis-
leading. If more than one symptom is present, possible causes
can be narrowed to make at least a partial diagnosis.

For example, an above normal consumption of oil could be
caused by several mechanical faults. But when accompanied
by blue-gray smoke from the exhaust and low compression, it
indicates the rings need replacing. Low compression by itself
is more likely to be caused by improperly seated or burned
valves, not worn rings.

Certain "knocking" noises may occur because of loose bear-
ings, others by piston slap. Piston slap is a condition where
piston or cylinder or both are out of tolerance. This excessive
clearance allows the piston to "slap" the cylinder as it moves
up and down.

Most frequently, valves, rings, pins, bushings and bearings
need attention at about the same time. If the symptoms indicate
that any one of the above components is worn, service all
related parts.

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3-20 2013 Softail Service: Engine