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Harley Davidson 1999-2005 Harley Dyna Models. Repair Manual - page 5

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80

CHAPTER THREE

9. When the drive belt deflection and axle align-

32

ment adjustments are correct, tighten the rear axle

nut (A, Figure 30) to the torque specification in Ta-

ble 6. Install the spring clip through the axle nut and

rear axle.

10. Lower the rear wheel to the ground.

Brake Pad Inspection

1. Without removing the front or rear brake calipers,

inspect the brake pads (Figure 33) for damage.

2. Measure the thickness of each brake pad lining

(Figure 34) with a ruler. Replace the brake pad if its

33

thickness is worn to the minimum thickness in Ta-

ble 8. Replace the brake pads as described in Chap-

ter Twelve.

Disc Brake Fluid Level

1. To check the front master cylinder, perform the

following:

a. Turn the handlebar so the master cylinder is

level.

b. Observe the brake fluid level by looking at

the sight glass (A, Figure 35) on the master

cylinder reservoir top cover. If the fluid level

34

BRAKE PAD

is correct, the sight glass will appear dark pur-

INSPECTION

ple. If the level is low, the sight glass will

have a lightened or clear appearance.

2. To check the rear master cylinder, perform the

following:

a. Support the motorcycle so that the rear master

cylinder is level.

NOTE

The rear master cylinder is partially

hidden by the exhaust system, as

shown in Figure 36, making it very

Friction

difficult to see the viewing port.

material

Backing

b. Observe the brake fluid level by looking at

plate

the sight glass on the side of the master cylin-

der reservoir. If the fluid level is correct, the

sight glass will appear dark purple. If the level

is low, the sight glass will have a lightened or

clear appearance.

Minimum thickness

c. If the fluid level can not be determined by

looking at the sight glass, remove the top cover

(Figure 37) and diaphragm as described in

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LUBRICATION, MAINTENANCE AND TUNE-UP

81

35

37

3

CAUTION

36

Cover all surrounding areas with a

heavy cloth or plastic tarp to protect

them from any accidental brake fluid

spills. Wash brake fluid off any surfaces

immediately, as it will destroy the finish.

Use soapy water and rinse completely.

NOTE

To control the flow of brake fluid, punch

a small hole in the seal of a new con-

tainer of brake fluid next to the edge of

the pour spout. This helps eliminate the

fluid spillage, especially while adding

fluid to the small reservoir.

Step 3. The brake fluid must be within 1/8

in.

(3.2 mm) from the top surface.

3. If the brake fluid level is low, perform the fol-

lowing:

WARNING

a. If necessary on the rear master cylinder, re-

Do not use brake fluid labeled DOT

move the front cylinder’s muffler as de-

5.1. This is a glycol-based fluid that is

scribed in Chapter Seven.

not compatible with silicone based

b. Clean any dirt from the master cylinder cover

DOT 5. DOT 5 brake fluid is purple

prior to removing it.

while DOT 5.1 is an amber/clear color.

c. Remove the top cover (B, Figure 35) and lift

Do not intermix these two completely

the diaphragm out of the reservoir.

different types of brake fluid, as doing

d. Add DOT 5 brake fluid to correct the level.

so will lead to brake component dam-

e. Reinstall the diaphragm and top cover.

age and possible brake failure.

Tighten the screws securely.

WARNING

NOTE

Only use brake fluid clearly marked

If the brake fluid level is low enough

DOT 5 and specified for disc brakes.

to allow air in the hydraulic system,

Others may vaporize, causing brake

bleed the brakes as described in

failure.

Chapter Twelve.

CAUTION

Front and Rear Brake Disc Inspection

Do not allow the master cylinder res-

ervoir to overflow when performing

Visually inspect the front and rear brake discs

Step 3. Brake fluid will damage most

(Figure 38, typical) for scoring, cracks or other

surfaces it contacts.

damage. Measure the brake disc thickness and, if

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82

CHAPTER THREE

necessary, service the brake discs as described in

38

Chapter Twelve.

Disc Brake Lines and Seals

Check the brake lines between each master cylin-

der and each brake caliper. If there is any leakage,

tighten the connections and bleed the brakes as de-

scribed in Chapter Twelve.

Disc Brake Fluid Change

Every time the reservoir cover is removed, a

small amount of dirt and moisture enters the brake

39

fluid. The same thing happens if a leak occurs or if

any part of the hydraulic system is loosened or dis-

connected. Dirt can clog the system and cause un-

necessary wear. Water in the fluid vaporizes at high

temperatures, impairing the hydraulic action and re-

ducing brake performance.

To change brake fluid, follow the brake bleeding

procedure in Chapter Twelve. Add new fluid to the

master cylinder until the fluid leaving the caliper is

clean and free of contaminants and air bubbles.

WARNING

Only use brake fluid clearly marked

40

DOT 5. Others may vaporize and

cause brake failure.

WARNING

Do not use brake fluid labeled DOT

5.1. This is a glycol-based fluid that is

not compatible with silicone-based

DOT 5. DOT 5 brake fluid is purple

while DOT 5.1 is an amber/clear color.

Do not intermix these two completely

different types of brake fluid, as doing

so will lead to brake component dam-

age and possible brake failure.

WARNING

Do not lengthen the brake rod to a

Front Disc Brake Adjustment

point where six or more threads are

visible on the brake rod. If six threads

The front disc brake does not require periodic ad-

are visible past the jam nut, there is

justment.

insufficient break rod thread engage-

ment into the master cylinder push

Rear Brake Pedal Height Adjustment

rod. This could cause the brake rod to

separate from the pushrod, making

The rear brake pedal on these models is not ad-

the rear brake inoperative.

justable. When the rear master cylinder is properly

assembled and mounted on the motorcycle, the

If minor height adjustment is required, perform

brake pedal assembly is properly adjusted.

the following:

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LUBRICATION, MAINTENANCE AND TUNE-UP

83

1. Loosen the brake rod jam nut (A, Figure 39)

41

next to the master cylinder.

2. Rotate the brake rod (B, Figure 39) in either di-

rection to gain the correct pedal height.

3. Tighten the jam nut securely.

4. If necessary, make sure the drain hole in the rub-

3

ber boot is positioned to the bottom.

Clutch Adjustment

CAUTION

Because the clutch cable adjuster

clearance increases with engine tem-

perature, adjust the clutch when the

42

engine is cold. If the clutch is adjusted

when the engine is hot, insufficient

pushrod clearance can cause the

clutch to slip.

1. Remove the clutch inspection cover and O-ring

(Figure 40).

2. Slide the rubber boot (A, Figure 41) off the

clutch in-line cable adjuster.

3. Loosen the adjuster locknut (B, Figure 41) and

turn the adjuster (C, Figure 41) to provide maxi-

mum cable slack.

4. Check that the clutch cable seats squarely in its

43

perch (Figure 42) at the handlebar.

5. At the clutch mechanism, loosen the clutch ad-

justing screw locknut (A, Figure 43) and turn the

adjusting screw (B, Figure 43) clockwise until it is

lightly seated.

6. Squeeze the clutch lever three times to verify the

clutch balls are seated in the ramp release mecha-

nism located behind the transmission side cover.

7. Back out the adjusting screw (B, Figure 43)

counterclockwise 1/2 to 1 turn. Then hold the ad-

justing screw (A, Figure 44) and tighten the locknut

(B, Figure 44) to the specification in Table 6.

8. Once again, squeeze the clutch lever to its maxi-

44

mum limit three times to set the clutch ball and

ramp release mechanism.

9. Check the free play as follows:

a. At the in-line cable adjuster, turn the adjuster

(C, Figure 41) away from the locknut until

slack is eliminated at the clutch hand lever.

b. Pull the clutch cable sheath away from the

clutch lever, then turn the clutch cable ad-

juster (C, Figure 41) to obtain the free play

(Figure 45) specified in Table 8.

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84

CHAPTER THREE

c. When the adjustment is correct, tighten the

45

clutch in-line cable locknut (B, Figure 41)

and slide the rubber boot over the cable ad-

juster.

10. Install the clutch inspection cover O-ring (Fig-

ure 46) onto the primary chain case cover.

11. Install the clutch inspection cover and tighten

the screws to the specification in Table 6.

Free play

Throttle Cables Inspection

Clutch cable

Inspect the throttle cables from grip to carburetor.

Make sure they are not kinked or chafed. Replace

them if necessary as described in Chapter Seven.

46

Make sure that the throttle grip rotates smoothly

from fully closed to fully open. Check with the han-

dlebar at center, full left and full right positions.

Throttle Cable Adjustment

There are two different throttle cables. One is the

throttle control cable (A, Figure 47 and A, Figure

48) and the other is the idle control cable (B, Figure

47 and B, Figure 48).

NOTE

The throttle control and idle control

47

cables have different sizes of threads

on the threaded adjusters. The throttle

control cable has a 5/16×18 adjuster.

The idle control cable has a 1/4×20

adjuster.

1. Remove the air filter and backing plate as de-

scribed in Chapter Seven.

2. At the handlebar, perform the following:

a. Slide the rubber boots off both cables (Figure

49).

b. Loosen both control cable adjuster locknuts

(A, Figure 50), then turn the cable adjusters

48

(B, Figure 50) clockwise as far as possible to

increase cable slack.

3. Turn the handlebars so that the front wheel

points straight ahead. Then turn the throttle grip to

open the throttle completely and hold it in this posi-

tion.

NOTE

Figure 51 is shown with the carbure-

tor body removed to better illustrate

the steps.

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LUBRICATION, MAINTENANCE AND TUNE-UP

85

4. At the handlebar, turn the throttle control cable

49

adjuster (A, Figure 52) counterclockwise until the

throttle cam (A, Figure 51) stop just touches the

stop boss (B, Figure 51) on the carburetor body.

Then tighten the throttle cable adjuster locknut and

release the throttle grip.

3

5. Turn the front wheel all the way to the full right

lock position and hold it there.

6. At the handlebar, turn the idle cable adjuster (B,

Figure 52) until the lower end of the idle control ca-

ble just contacts the spring in the carburetor cable

guide

(C, Figure

51). Tighten the idle cable

locknut.

50

7. Shift the transmission into NEUTRAL and start

the engine.

8. Increase engine speed several times. Release the

throttle and make sure engine speed returns to idle.

If engine speed does not return to idle, at the handle-

bar, loosen the idle control cable adjuster locknut

and turn the cable adjuster (B, Figure 52) clockwise

as required. Tighten the idle control cable adjuster

locknut.

9. Allow the engine to idle in NEUTRAL. Then

turn the handlebar from side to side. Do not operate

the throttle. If the engine speed increases when the

handlebar assembly is turned, the throttle cables are

51

routed incorrectly or damaged. Turn off the engine.

Recheck cable routing and adjustment.

WARNING

Do not ride the motorcycle until the

throttle cables are properly adjusted.

Likewise, the cables must not catch or

pull when the handlebar is turned

from side to side. Improper cable

routing and adjustment can cause the

throttle to stick open. This could cause

loss of control and a possible crash.

Recheck this adjustment before riding

the motorcycle.

52

Starting Enrichment Valve (Choke)

Cable Adjustment

The starting enrichment (choke) knob (Figure

53) must move from fully open to fully closed with-

out any sign of binding. The knob must also stay in

its fully closed or fully open position without creep-

ing.

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86

CHAPTER THREE

53

54

ENRICHENER CABLE

Enrichener knob

Washer

Flat

Plastic knurled

Hex nut

nut

55

AIR FILTER

1. Backplate (International)

2. Grommet (California)

3. Backplate (California)

4. O-ring

5. Gasket

6. Backplate (49-state)

7. Breather hollow bolt

8. Breather hose

9. Gasket

10. Air filter

11. Mounting bracket

12. Bolts

13. Nut clip

14. Enrichment cable

bracket

15. Cable strap

16. Nut

17. Grommet

18. Bolt

19. Screw

20. Trim

21. Cover

22. Gasket

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LUBRICATION, MAINTENANCE AND TUNE-UP

87

56

57

3

If the knob does not stay in position, adjust ten-

spills onto a hot engine or exhaust

sion on the cable by turning the plastic knurled nut

pipe.

behind the knob (Figure 54) as follows:

CAUTION

Exhaust System

The starting enrichment (choke) cable

must have sufficient cable resistance

Check all fittings for exhaust leakage. Do not for-

to work properly. Do not lubricate the

get the crossover pipe connections. Tighten all bolts

enrichment cable or its conduit.

and nuts. Replace any gaskets as necessary. See

Chapter Seven for removal and installation proce-

1. Loosen the hex nut behind the mounting bracket.

dures.

Then move the cable to free it from its mounting

bracket slot.

2. Hold the cable across its flats with a wrench and

Air Filter Element

turn the plastic knurled nut counterclockwise to re-

Removal/Installation

duce cable resistance. The knob must slide inward

Remove and inspect the air filter at the interval

freely.

in Table 1. If necessary, clean the element. Re-

3. Turn the plastic knurled nut (Figure 54) clock-

place the element if it is damaged or starts to dete-

wise to increase cable resistance. Continue adjust-

riorate.

ment until the knob remains stationary when pulled

all the way out. The knob must move without any

The air filter removes dust and abrasive particles

roughness or binding.

before the air enters the carburetor and the engine.

Without the air filter, very fine particles could enter

4. Reinstall the cable into the slot in its mounting

into the engine and cause rapid wear of the piston

bracket with the star washer located between the

rings, cylinder bores and bearings. They also might

bracket and hex nut. Tighten the hex nut securely.

clog small passages in the carburetor. Never run the

5. Recheck the knob movement and readjust if nec-

motorcycle without the element installed.

essary.

Refer to Figure 55 for this procedure.

1. Remove the air filter cover screw (A, Figure 56)

Fuel Line Inspection

and remove the cover (B, Figure 56).

2. Remove the Torx screws and bracket (A, Figure

Inspect the fuel lines from the fuel tank to the car-

57) from the air filter element.

buretor. Replace leaking or damaged fuel lines.

3. Gently pull the air filter element away from the

Make sure the hose clamps are in place and holding

backplate and disconnect the two breather hoses

securely. Check the hose fittings for looseness.

from the breather hollow bolts on the backplate. Re-

move the air filter element (B, Figure 57).

WARNING

A damaged or deteriorated fuel line

4. Clean the air filter as described in the following

can cause a fire or explosion if fuel

procedure.

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88

CHAPTER THREE

5. Inspect the gasket (Figure 58) for damage. Re-

58

place if necessary.

6. Inspect the breather hoses (Figure 59) for tears

or deterioration. Replace if necessary.

NOTE

Figure 60 is shown with the air filter

backplate removed to better illustrate

the step.

7. On California models, make sure the trap door

swings freely (Figure 60).

8. If removed, install a new gasket (Figure 58) and

breather hoses (Figure 59).

9. Position the element with the flat side facing

59

down and attach the breather hoses (Figure 61) to

the backside of the element (Figure 62).

NOTE

If an aftermarket air filter element is

being installed, position it onto the

backplate following the manufac-

turer’s instructions.

10. Move the element into position (B, Figure 57)

and install the mounting bracket (A, Figure 57) and

the Torx screws. Tighten the screws to the specifica-

tion in Table 6.

11. Apply a drop of ThreeBond TB1342 (blue), or

60

an equivalent, threadlocking compound to the cover

screw prior to installation.

12. Inspect the seal ring (Figure 63) on the air filter

cover for hardness or deterioration. Replace if nec-

essary.

13. Install the air filter cover (B, Figure 56) and the

screw (A, Figure 56). Tighten the screw to the spec-

ification in Table 6.

Air Filter Element Cleaning

vent or vapors left by these chemicals

The air filter element is a paper/wire type (Figure

may cause a fire or explosion after the

64). If an aftermarket element is installed, refer to

filter is reinstalled.

the manufacturer’s cleaning instructions.

1. Remove the air filter element as described in this

CAUTION

chapter.

Do not tap or strike the air filter ele-

ment on a hard surface to dislodge

2. Replace the air filter if damaged.

dirt. Doing so will damage the ele-

WARNING

ment.

Do not clean the air filter in any type

of solvent. Never clean the air filter

3.

Place the air filter in a pan filled with lukewarm

element in gasoline or any type of low

water and mild detergent. Move the air filter ele-

flash point solvent. The residual sol-

ment back and forth to help dislodge trapped dirt.

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LUBRICATION, MAINTENANCE AND TUNE-UP

89

Thoroughly rinse in clean water to remove all deter-

61

gent residue.

4. Remove the air filter and hold it up to a strong

light. Check the filter pores for dirt and oil. Repeat

Step 3 until there is no longer dirt and oil in the filter

pores. If the air filter cannot be cleaned, or if the fil-

3

ter is saturated with oil or other chemicals, replace

it.

CAUTION

Do not use high air pressure to dry the

filter, as this will damage it.

CAUTION

62

In the next step, do not blow com-

pressed air through the outer surface

of the air filter element. Doing so can

force dirt trapped on the outer filter

surface deeper into the air filter ele-

ment, restricting airflow and damag-

ing the air filter element.

5. Gently apply compressed air through the inside

surface of the air filter element to remove loosened

dirt and dust trapped in the filter.

6. Inspect the air filter element. Replace if torn or

63

damaged. Do not ride the motorcycle with a dam-

aged filter element as it may allow dirt to enter the

carburetor and engine.

7. Clean the breather hoses in the same lukewarm

water and mild detergent. Make sure both hoses are

clean and clear. Clean out with a pipe cleaner if nec-

essary.

8. Wipe the inside of the cover and backplate with a

clean damp shop rag.

CAUTION

Air will not pass through a wet or

damp filter. Make sure the filter is dry

64

before installing it.

9. Allow the filter to dry completely, then reinstall

it as described in this chapter.

Steering Play

Check the steering head play (Chapter Ten) at the

intervals specified in Table 1.

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CHAPTER THREE

Rear Swing Arm Pivot Bolt

65

Check the rear swing arm pivot bolt tightness

(Chapter Eleven) at the fastener interval specified in

Table 1.

Rear Shock Absorbers

Check the rear shock absorbers for oil leakage or

damaged bushings. Check the shock absorber

mounting bolts and nuts for tightness. Refer to

Shock Absorbers in Chapter Eleven for procedures.

66

Engine Mounts and Stabilizer

Check the stabilizer and the engine and frame

mounts for loose or damaged parts. Refer to Chap-

ter Four for procedures.

CAUTION

Special procedures must be used

when tightening the cylinder head

mounting bolts. To accurately check

these bolts for tightness, refer to Cyl-

inder Head Installation in Chapter

TUNE-UP

Four. Tightening these bolts incor-

rectly can cause an oil leak or cylin-

A complete tune-up restores

performance

and

der head warpage.

power lost due to normal wear and deterioration of

engine parts. Because engine wear occurs over a

Fasteners

combined period of time and mileage, perform the

engine tune-up procedures at the intervals specified

Constant vibration can loosen many fasteners on

in Table 1. More frequent tune-ups may be required

a motorcycle. Check the tightness of all fasteners,

if the motorcycle is operated primarily in

especially those on:

stop-and-go traffic.

Replace the spark plugs at every other tune-up or

1. Engine mounting hardware.

if the electrodes show signs of wear, fouling or ero-

2. Engine and primary covers.

sion.

3. Handlebar and front fork.

Perform the procedures in the following order

4. Gearshift lever.

and refer to Table 8 for specifications.

5. Sprocket bolts and nuts.

1. Clean or replace the air filter element.

6. Brake pedal and lever.

2. Check engine compression.

7. Exhaust system.

3. Check or replace the spark plugs.

4. Adjust carburetor idle speed.

8. Lighting equipment.

Air Filter

Electrical Equipment and Switches

Clean the air filter element before performing

Check all of the electrical equipment and

other tune-up procedures. Refer to Air Filter Ele-

switches for proper operation.

ment in this chapter.

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LUBRICATION, MAINTENANCE AND TUNE-UP

91

5. Place the throttle in the wide-open position.

67

Make sure the starting enrichment (choke) knob

(Figure 67) is pushed in fully to the OFF position.

6. Crank the engine over until there is no further

rise in pressure.

7. Record the reading and remove the tester.

3

8. Repeat Steps 4-7 for the other cylinder.

9. Reinstall the spark plugs and reconnect their

caps.

Results

When interpreting the results, actual readings are

not as important as the difference between the read-

68

ings. Table 8 lists the standard engine compression

reading. Pressure must not vary between the cylin-

ders by more than 10 percent. Greater differences

indicate worn or broken rings, leaky or sticky

valves, blown head gasket or a combination of all.

If compression readings do not differ between

cylinders by more than 10 percent, the rings and

valves are in good condition. A low reading (10 per-

cent or more) on one cylinder indicates valve or ring

trouble. To decide which, pour about a teaspoon of

engine oil into the spark plug hole. Turn the engine

over once to distribute the oil, then take another

Compression Test

compression test and record the reading. If the com-

pression increases significantly, the valves are good

A compression check is one of the most effective

but the rings are defective on that cylinder. If com-

ways to check the condition of the engine. Check

pression does not increase, the valves require ser-

the compression at each tune-up, record the read-

vicing.

ings and compare them to readings at subsequent

tune-ups. This will help spot any developing prob-

NOTE

lems.

An engine cannot be tuned to maxi-

mum performance with low compres-

1. Prior to starting the compression test, make sure

sion.

the following is correct:

a. The cylinder head bolts are tightened to the

torque specification. Refer to Chapter Four.

Spark Plug Removal

b. The battery is fully charged to ensure proper

CAUTION

engine cranking speed.

Whenever the spark plug is removed,

2. Warm the engine to normal operating tempera-

dirt around it can fall into the plug

hole. This can cause serious engine

ture. Shut off the engine.

damage.

3. Remove the spark plugs and reinstall them in

their caps (Figure 65). Place the spark plugs against

1. Blow away any loose dirt or debris that may

the cylinder head to ground them.

have accumulated around the base of the spark plug

4. Connect the compression tester to one cylinder,

that could fall into the cylinder head.

following its manufacturer’s instructions (Figure

2. Grasp the spark plug lead (Figure 68), and twist

66).

from side to side to break the seal loose. Then pull

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92

CHAPTER THREE

the cap off the spark plug. If the cap is stuck to the

69

plug, twist it slightly to break it loose.

NOTE

Use a special spark plug socket

equipped with a rubber insert that

holds the spark plug. This type of

socket is necessary for both removal

and installation since the spark plugs

are recessed in the cylinder head.

3. Install the spark plug socket onto the spark plug.

Make sure it is correctly seated and install an

open-end wrench or socket handle and remove the

spark plug. Mark the spark plug with which cylin-

der number it was removed from.

4. Repeat for the remaining spark plug.

5. Thoroughly inspect each plug. Look for broken

center porcelain, excessively eroded electrodes and

excessive carbon or oil fouling.

NOTE

Spark plug cleaning with a

sand-blasting device is not recom-

mended. While this type of cleaning is

(Figure 70) to adjust the proper gap listed in Table

thorough, the plug must be completely

8.

free of all abrasive cleaning material

3. Apply a light coat of antiseize lubricant on the

when done. If not, it is possible for the

threads of the spark plug before installing it. Do not

abrasive material to fall into the cyl-

inder during operation and cause

use engine oil on the plug threads.

damage.

CAUTION

The cylinder head is aluminum and

6. Inspect the spark plug caps and secondary wires

the spark plug hole can be easily dam-

for damage, or hardness. If any portion is damaged,

aged by cross-threading the spark

the cap and secondary wire must be replaced as an

plug.

assembly. The front and rear cylinder assemblies

have different part numbers.

4. Slowly screw the spark plug into the cylinder

head by hand until it seats. Very little effort is re-

quired. If force is necessary to remove the plug , it is

Spark Plug Gapping and Installing

cross-threaded; unscrew it and try again.

Carefully gap the spark plugs to ensure a reliable,

NOTE

consistent spark. A special spark plug gapping tool

Do not overtighten. This will only

and a wire feeler gauge must be used.

squash the gasket and destroy its seal-

1. Remove the new spark plugs from the boxes. In-

ing ability.

stall the small adapter onto the end of the spark plug

that may be loose in the box.

5. Hand-tighten the plug until it seats against the

2. Insert a wire feeler gauge between the center and

cylinder head, then tighten to the specification in

side electrode of the plug (Figure 69). The correct

Table 6.

gap is listed in Table 8. If the gap is correct, a slight

6. Install the spark plug cap and lead to the correct

drag will be felt as the wire gauge is pulled through.

spark plug. Rotate the cap slightly in both directions

If there is no drag, or the gauge will not pass

and make sure it is attached to the spark plug.

through, bend the side electrode with a gapping tool

7. Repeat for the other spark plug.

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LUBRICATION, MAINTENANCE AND TUNE-UP

93

In general, use a hot plug for low speeds and low

70

temperatures. Use a cold plug for high speeds, high

engine loads and high temperatures. The plug

should operate hot enough to burn off unwanted de-

posits, but not so hot that it is damaged or causes

preignition. To determine if plug heat range is cor-

3

rect, remove each spark plug and examine the insu-

lator.

Do not change the spark plug heat range to com-

pensate for adverse engine or carburetion condi-

tions.

When replacing plugs, make sure the reach (Fig-

ure 71) is correct. A longer than standard plug could

interfere with the piston, causing engine damage.

Refer to Table 8 for recommended spark plugs.

Spark Plug Reading

Reading the spark plugs can provide a significant

amount of information regarding engine perfor-

mance. Reading plugs that have been in use will

give an indication of spark plug operation, air/fuel

mixture composition and engine conditions (such as

oil consumption or pistons). Before checking the

spark plugs, operate the motorcycle under a me-

dium load for approximately 6 miles (10 km).

71

Avoid prolonged idling before shutting off the en-

gine. Remove the spark plugs as described in this

chapter. Examine each plug and compare it to those

in Figure 72 while referring to the following sec-

tions to determine the operating conditions.

If the plugs are being read to determine if carbure-

tor jetting is correct, start with new plugs and operate

the motorcycle at the load that corresponds to the jet-

ting information desired. For example, if the main jet

is in question, operate the motorcycle at full throttle

and shut the engine off and coast to a stop.

Too short

Correct

Too long

Normal condition

If the plug has a light tan- or gray-colored deposit

Spark Plug Heat Range

and no abnormal gap wear or erosion, good engine,

air/fuel mixture and ignition conditions are indi-

Spark plugs are available in various heat ranges,

cated. The plug in use is of the proper heat range and

hotter or colder than the plugs originally installed

may be serviced and returned to use.

by the manufacturer.

Select a plug with a heat range designed for the

Carbon fouled

loads and conditions under which the motorcycle

will be operated. A plug with an incorrect heat range

Soft, dry, sooty deposits covering the entire firing

can foul, overheat and cause piston damage.

end of the plug are evidence of incomplete combus-

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94

CHAPTER THREE

72

SPARK PLUG CONDITIONS

OIL FOULED

GAP BRIDGED

• Identified by wet black deposits

• Identified by deposit buildup

on the insulator shell bore and

NORMAL

closing the gap between elec-

electrodes.

• Identified by light tan or gray

• Caused by excessive oil enter-

trodes.

deposits on the firing tip.

ing the combustion chamber

• Can be cleaned.

• Caused by oil or carbon fouling.

through worn rings or pistons,

If deposits are not excessive,

excessive clearance between

the plug can be cleaned.

the valve guides and stems or

worn or loose bearings. Can be

cleaned. If engine is not re-

paired, use a hotter plug.

CARBON FOULED

LEAD FOULED

• Identified by black, dry fluffy

• Identified by dark gray, black, yel-

carbon deposits on insulator

low or tan deposits or a fused

WORN

tips, exposed shell surfaces

glazed coating on the insulator

• Identified by severely eroded or

and electrodes.

tip.

worn electrodes.

• Caused by a too-cold plug,

• Caused by highly leaded gaso-

• Caused by normal wear. It

weak ignition, dirty air cleaner,

line. Can be cleaned.

should be replaced.

too rich fuel mixture or exces-

sive idling. Can be cleaned.

OVERHEATING

PREIGNITION

• Identified by a white or light

• Identified by melted electrodes

gray insulator with small black

and possibly blistered insula-

or gray brown spots with blu-

FUSED SPOT DEPOSIT

tor. Metallic deposits on insula-

ish-burnt appearance of elec-

• Identified by melted or spotty

tor indicate engine damage.

trodes.

deposits resembling bubbles or

• Caused by wrong type of fuel,

• Caused by engine overheating,

blisters.

incorrect ignition timing or ad-

wrong type of fuel, loose spark

• Caused by sudden accelera-

vance, too hot a plug, burned

plugs, too hot a plug or incor-

tion. Can be cleaned.

valves or engine overheating.

rect ignition timing. Replace the

Replace the plug.

plug.

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96

CHAPTER THREE

2. Make sure the starting enrichment (choke) valve

73

(Figure 67) is pushed all the way to the OFF posi-

tion.

3. On models without a tachometer, connect a por-

table tachometer to the engine, following its manu-

facturer’s instructions.

NOTE

Figure 73 is shown with the air filter

assembly removed to better illustrate

the step.

4. Start the engine and, with the engine idling,

compare the tachometer reading to the idle speed

5. Accelerate the engine a couple of times and re-

specification in Table 8. If the tachometer reading is

lease the throttle. The idle speed must return to the

incorrect, adjust the idle speed with the carburetor

speed set in Step 4. If necessary, readjust the idle

throttle stop screw (Figure 73).

speed by turning the throttle stop screw (Figure

73). Shut off the engine.

NOTE

The idle mixture is set and sealed by the

6. If installed, disconnect and remove the portable

manufacturer and is not adjustable.

tachometer.

Table 1 MAINTENANCE AND LUBRICATION SCHEDULE¹

Pre-ride check

Check tire condition and inflation pressure

Check wheel rim condition

Check engine oil level; add oil if necessary

Check brake fluid level and condition; add fluid if necessary

Check brake lever operation and travel

Check throttle and choke (enrichener) cable operation

Check fuel level in fuel tank; top off if necessary

Check drive belt tension

Initial 500 miles (800 km)

Change engine oil and filter

Check battery condition; clean cable connections if necessary

Check brake fluid level and condition; add fluid if necessary

Check front and rear brake pads and discs for wear

Check tire for correct inflation pressure and for excessive wear or damage

Check primary chain deflection; adjust if necessary

Check drive belt tension; adjust if necessary

Change primary chain case lubricant

Change transmission lubricant

Check clutch lever operation; adjust if necessary

Check drive belt and sprockets condition

Inspect spark plugs

Inspect air filter element for dirt and damage

Lubricate front brake and clutch lever pivot pin

(continued)

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