Harley Davidson 1999-2005 Harley Dyna Models. Repair Manual

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CHAPTER FOUR

3. Tap the cylinder head with a rubber mallet to free

it, then lift it off the cylinder block.

4. Remove the cylinder head gasket.

5. Remove the two O-rings and the cylinder head

dowel pins (Figure 65).

6. Repeat these steps to remove the opposite cylin-

der head.

Inspection

1. Thoroughly clean the outside of the cylinder

head. Use a stiff brush, soap and water and remove

all debris from the cooling fins (Figure 66). If nec-

essary, use a piece of wood and scrape away any

lodged dirt. Clogged cooling fins can cause over-

heating, leading to possible engine damage.

2. Without removing the valves, use a wire brush

to remove all carbon deposits from the combustion

chamber. Use a fine wire brush dipped in solvent

or make a scraper from hardwood. Take care not to

damage the head, valves or spark plug threads.

CAUTION

Cleaning the combustion chamber

with the valves removed can damage

the valve seat surfaces. A damaged or

even slightly scratched valve seat will

cause poor valve seating.

3. Examine the spark plug threads in the cylinder

head for damage. If damage is minor or if the

threads are dirty or clogged with carbon, use a spark

plug thread tap (Figure 67) to clean the threads fol-

lowing the manufacturer’s instructions. If thread

damage is severe, restore the threads by installing a

steel thread insert. Purchase thread insert kits at au-

tomotive supply stores or have them installed by a

Harley-Davidson dealership or machine shop.

NOTE

When using a tap to clean spark plug

threads, coat the tap with an alumi-

num tap-cutting fluid or kerosene.

NOTE

Aluminum spark plug threads are

commonly damaged due to galling,

cross-threading and over-tightening.

To prevent galling, apply an antiseize

compound on the plug threads before

installation and do not overtighten.

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ENGINE

121

4. After all carbon is removed from combustion

chambers and valve ports, and, if necessary, the

spark plug thread hole is repaired, clean the entire

head in solvent. Blow dry with compressed air.

5. Examine the crown on the piston (Figure 68).

The crown should show no signs of wear or dam-

age. If the crown appears pecked or spongy, also

check the spark plug, valves and combustion cham-

ber for aluminum deposits. If these deposits are

found, the cylinder has overheated. Check for a lean

fuel mixture or other conditions that could result in

preignition.

6. Check for cracks in the combustion chamber, the

intake port (Figure 69), the exhaust port (Figure

70). Replace a cracked head if welding can not re-

pair it.

7. Inspect the threads (Figure 71) for the exhaust

pipe mounting bolts for damage. Repair with a tap if

damaged.

NOTE

If the cylinder head is bead-blasted,

clean the head thoroughly with sol-

vent and then with hot soapy water.

Residue grit seats in small crevices

and other areas and can be hard to get

out. Also run a tap through each ex-

posed thread to remove grit from the

threads. Residue grit left in the engine

will cause premature wear.

8. Thoroughly clean the cylinder head.

9. Place a straightedge across the gasket surface at

several points and measure for warp by attempting

to insert a feeler gauge between the straightedge

and cylinder head at each location (Figure 72).

Maximum allowable warp is listed in Table 2. Dis-

tortion or nicks in the cylinder head surface could

cause an air leak and result in overheating. If warp

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122

CHAPTER FOUR

exceeds the limit, the cylinder head must be resur-

faced or replaced. Consult a Harley-Davidson

dealership or machine shop experienced in this

type of work.

10. Check the rocker arm housing mating surfaces

for warp (Figure 73) using the procedure in Step 9.

11. Make sure the breather channel is clear at each

end (Figure 74).

12. Check the valves and valve guides as described

under Valves and Valve Components in this chapter.

Installation

1. If removed, install the piston and cylinder as de-

scribed in this chapter.

2. Lubricate the cylinder studs and cylinder head

bolts as follows:

a. Clean the cylinder head bolts in solvent and

dry with compressed air.

b. Apply clean engine oil to the cylinder head

bolt threads and to the flat shoulder surface on

each bolt (Figure 75). Wipe off any excess oil

from the bolts, leave only an oil film on these

surfaces.

3. Install the two dowel pins (Figure 65) into the

top of the cylinder block.

4. Install a new O-ring over each dowel pin. Apply

a light coat of clean engine oil to the O-rings.

CAUTION

Because the O-rings center the head

gasket on the cylinder block, install

them before installing the head gas-

ket.

5. Install a new cylinder head gasket (Figure 76)

onto the cylinder block.

CAUTION

Do not use sealer on the cylinder head

gasket. If using an aftermarket head

gasket, follow the manufacturer’s in-

structions for gasket installation.

NOTE

The cylinder heads are not identical.

Refer to the FRONT or REAR mark

(Figure 77) cast into the top surface

of the cylinder head.

6. Install the cylinder head (Figure 78) onto the

cylinder block and the dowel pins. Position the head

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ENGINE

123

carefully to avoid moving the head gasket out of

alignment.

7. Install the cylinder head long bolts in the center

bolt holes; install the short bolts in the outer bolt

holes next to the spark plug hole. Tighten the cylin-

der head bolts (Figure 64) only finger-tight at this

time.

CAUTION

Failure to follow the torque pattern

and sequence in Step 8 may cause cyl-

inder head distortion and gasket leak-

age.

8. Refer to Figure 79 for the front and rear cylinder

head bolt tightening sequence. Torque the cylinder

head bolts as follows:

Front cylinder head

Rear cylinder head

a. Starting with bolt No. 1, tighten each bolt in

order to 84-108 in.-lb. (9-12 N•m).

b. Starting with bolt No. 1, tighten each bolt in

order to 144-168 in.-lb. (16-19 N•m).

c. Make a vertical mark with a permanent

marker on each bolt head (A, Figure 80).

Make another mark on the cylinder head (B,

Figure 80) at a 90-degree angle, or 1/4 turn

from the mark on the bolt head.

d. Use the marks as a guide and tighten each

bolt head 90 degrees, or 1/4 turn, clockwise

until the match marks are aligned (Figure

81).

9. Install the rocker arm assemblies and pushrods

as described in this chapter.

VALVES AND VALVE COMPONENTS

Complete valve service requires a number of spe-

cial tools, including a valve spring compressor, to

remove and install the valves. The following proce-

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124

CHAPTER FOUR

dures describe how to check for valve component

wear and to determine what type of service is re-

quired.

Valve Removal

1. Remove the cylinder head as described in this

chapter.

2. Install the valve spring compressor (Figure 82)

squarely over the valve spring upper retainer (Fig-

ure 83) and against the valve head.

CAUTION

To avoid loss of spring tension, com-

press the spring only enough to re-

move the valve keepers.

3. Tighten the valve spring compressor until the

valve keepers separate from the valve stem. Lift the

valve keepers out through the valve spring com-

pressor with a magnet or needlenose pliers.

4. Gradually loosen the valve spring compressor

and remove it from the cylinder head.

5. Remove the spring retainer and the

valve

springs.

CAUTION

Remove any burrs from the valve stem

groove before removing the valve

(Figure

84); otherwise the valve

Deburr

guide will be damaged as the valve

stem passes through it.

6. Remove the valve from the cylinder while rotat-

ing it slightly.

Valve stem

7. Remove the valve spring lower retainer.

8. Remove the valve guide oil seal.

CAUTION

Keep the components of each valve

assembly together by placing each set

in a divided carton, or into separate

small boxes or small reclosable plas-

tic bags. Identify the components as

either intake or exhaust. If both cylin-

ders are disassembled, also label the

components as front and rear. Do not

intermix components from the valves

or excessive wear may result.

9. Repeat Steps 3-8 and remove the remaining

valve.

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ENGINE

125

Valve Inspection

When measuring the valves and valve compo-

nents in this section, compare the actual measure-

ments to the new and wear limit specifications in

Table 2. Replace parts that are out of specification

or show damage as described in this section.

1. Clean valves in solvent. Do not gouge or damage

the valve seating surface.

2. Inspect the valve face. Minor roughness and pit-

ting (Figure 85) can be removed by lapping the

valve as described in this chapter. Excessive un-

evenness to the contact surface is an indication that

the valve is not serviceable.

3. Inspect the valve stem for wear and roughness.

Then measure the valve stem outside diameter with

a micrometer (Figure 86).

4. Remove all carbon and varnish from the valve

guides with a stiff spiral wire brush before measur-

ing wear.

5. Measure the valve guide inside diameter with a

small hole gauge (Figure 87). Measure at the top,

center and bottom positions. Then measure the

small hole gauge.

6. Determine the valve stem-to-valve guide clear-

ance by subtracting the valve stem outside diame-

ter from the valve guide inner diameter. Compare

this measurement to the specification listed in Ta-

Valve

Dial gauge

ble 2.

7. If a small hole gauge is not available, insert

each valve into its guide. Attach a dial indicator to

the valve stem next to the head (Figure 88). Hold

the valve just slightly off its seat and rock it side-

ways in both directions 90 degrees to each other.

If the valve rocks more than slightly, the guide is

probably worn. However, as a final check, take

the cylinder head to a Harley-Davidson dealer-

ship or machine shop and have the valve guides

measured.

8. Check the inner and outer valve springs as fol-

lows:

a. Check each of the valve springs (Figure 89)

for visual damage.

b. Use a square and visually check the spring for

distortion or tilt (Figure 90).

c. Measure the valve spring free length with a

vernier caliper (Figure 91) and check against

the dimension in Table 2.

d. Repeat for each valve spring.

e. Replace defective springs as a set (inner and

outer).

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126

CHAPTER FOUR

9. Check the valve spring upper and lower retainers

seats for cracks or other damage.

10. Check the valve keepers and their fit onto the

valve stem end (Figure 92). They must index

tightly into the valve stem groove.

11. Inspect the valve seats (Figure 93) in the cylin-

der head. If worn or burned, they may be recondi-

tioned as described in this chapter. Seats and valves

in near-perfect condition can be reconditioned by

lapping with fine carborundum paste. Check as fol-

lows:

a. Clean the valve seat and corresponding valve

mating areas with contact cleaner.

b. Coat the valve seat with layout fluid.

c. Install the valve into its guide and tap it

against its seat with a valve lapping tool. Do

not rotate the valve.

d. Lift the valve out of the guide and measure

the seat width at various points around the

seat with a vernier caliper.

e. Compare the seat width with the specification

in Table 2. If the seat width is less than speci-

fied or uneven, resurface the seats as de-

scribed in this chapter.

f. Remove all layout fluid residue from the seats

and valves.

Valve Installation

1. Clean the end of the valve guide.

2. Install the spring lower retainer (Figure 94).

Push it down until it is seated on the cylinder head

surface (Figure 95).

3. Coat a valve stem with Torco MPZ, molybde-

num disulfide paste or equivalent. Install the valve

part way into the guide. Then, slowly turn the valve

as it enters the oil seal and continue turning it until

the valve is installed all the way.

4. Work the valve back and forth in the valve guide

to ensure the lubricant is distributed evenly within

the valve guide.

5. Withdraw the valve and apply an additional coat

of the lubricant.

6. Reinstall the valve into the valve guide but do

not push the valve past the top of the valve guide.

7. Use isopropyl alcohol and thoroughly clean all

traces of lubricant from the outer surface of the

valve guide.

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ENGINE

127

CAUTION

Do not allow any of the retaining

compound to enter the valve guide

bore.

8. Apply Loctite Retaining Compound RC/620, or

an equivalent, to the oil seal seating surface and to

the outer surface of the valve guide.

9. Push the valve all the way into the cylinder head

until it bottoms (A, Figure 96).

CAUTION

The oil seal will be torn as it passes

the valve stem keeper groove if the

plastic capsule is not installed in Step

10. The capsule is included in the top

end gasket set.

10. Hold the valve in place and install the plastic

capsule (B, Figure 96) onto the end of the valve

stem. Apply a light coat of clean engine oil to the

outer surface of the capsule.

11. With the valve held in place, install the oil seal

(Figure 97) onto the valve stem.

12A. If special tools are used, use the

Harley-Davidson Valve Seal Installation tool

(part No. HD-34643A) and driver handle (part

No. HD-34740) (Figure 98) and push the oil seal

down until it bottoms on the cylinder head sur-

face.

12B. If special tools are not used, use an appropri-

ate-size deep socket (Figure 99), and push the oil seal

down until it bottoms on the cylinder head surface.

13. Remove the plastic capsule from the valve

stem. Keep the capsule as it will be used on the re-

maining valves.

14. Install the inner valve spring (Figure 100) and

make sure it is properly seated on the lower spring

retainer.

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128

CHAPTER FOUR

VALVE SEAL

INSTALLATION

100

1. Driver handle

2. Valve seal installation tool

3. Valve guide seal

101

4. Valve guide

5. Lower spring seat

15. Install the outer valve spring (Figure 101) and

make sure it is properly seated on the lower spring

retainer.

16. Install the upper spring retainer (Figure 102)

on top of the valve springs.

CAUTION

To avoid loss of spring tension, com-

press the springs only enough to in-

102

stall the valve keepers.

17. Compress the valve springs with a valve spring

compressor (Figure 82) and install the valve keep-

ers (Figure 103).

18. Make sure both keepers are seated around the

valve stem prior to releasing the compressor.

19. Slowly release tension from the compressor

and remove it. After removing the compressor, in-

spect the valve keepers to make sure they are prop-

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ENGINE

129

erly seated (Figure 104). Tap the end of the valve

103

stem with a soft-faced hammer to ensure that the

keepers are properly seated.

20. Repeat Steps 1-19 for the remaining valves.

21. Install the cylinder head as described in this

chapter.

Valve Guide Replacement

Tools

The following tools or their equivalents are re-

quired to replace the valve guides.

1. Driver handle and remover (HD-34740).

104

2. Valve guide installation sleeve (HD-34741).

3. Valve guide, reamer

(HD-39932) and

T-handle (HD-39847).

4. Valve guide reamer (HD-39964) and honing

lubricant.

5. Valve guide hone (HD-34723).

6. Valve guide brush (HD-34751).

Procedure

1. Place the cylinder head on a wooden surface

with the combustion chamber side facing down.

105

2. Shoulderless valve guides (Figure 105) are used.

Before the valve guides are removed, note and record

the shape of the guide that projects into the combus-

tion chamber. If the valve guide installation tool is

not going to be used, measure the distance from the

face of the guide to the cylinder head surface with a

vernier caliper (Figure 106). Record the distance for

each valve guide. The new valve guides must be in-

stalled to this exact same height dimension.

3. Remove the valve guides as follows:

CAUTION

Use the correct size valve guide re-

106

moval tool when removing the valve

guides; otherwise, the tool may ex-

pand the end of the guide. An ex-

panded guide will widen and damage

the guide bore in the cylinder head as

it passes through it.

NOTE

The valve guides can either be

pressed out or driven out. Pressing

out is recommended since it lessens

the chance of cylinder head damage.

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130

CHAPTER FOUR

a. Support the cylinder head so that the combus-

tion chamber faces down.

107

b. If driving the guides out, place the cylinder on

a piece of wood.

c. If pressing the guides out, support the cylin-

der head in the press so that the valve guide is

perpendicular to the press table with a cylin-

der head stand (JIMS part No. 39782).

d. Insert the driver handle and remover into the

top of the valve guide.

e. Press or drive the valve guide out through the

combustion chamber.

f. Repeat for the remaining valve guides.

4. Clean the valve guide bores in the cylinder head.

5. Because the valve guide bores in the cylinder

head may have enlarged during removal of the old

guides, measure each valve guide bore prior to pur-

chasing the new guides. Then purchase the new

valve guides to match its respective bore diameter.

Determine the bore diameter as follows:

a. Measure the valve guide bore diameter in the

cylinder head with a bore gauge or snap

gauge. Record the bore diameter.

b. The new valve guide outside diameter must be

0.0020-0.0033 in.

(0.050-0.084

mm) larger

guide’s installed height using a vernier caliper (Fig-

than the guide bore in the cylinder head. When

ure 106) when installing it.

purchasing new valve guides, measure the new

guide’s outside diameter with a micrometer. If

NOTE

the new guide’s outside diameter is not within

Replacement valve guides are sold

this specification, oversize valve guide(s) must

with a smaller inside diameter than

be installed. See a Harley-Davidson dealership

the valve stem, so the guide must be

reamed to fit the valve stem.

for available sizes.

6. Apply a thin coating of molylube or white grease

8. Ream the new valve guide as follows:

to the entire outer surface of the valve guide before

a. Apply a liberal amount of reamer lubricant to

installing it in the cylinder head.

the ream bit and to the valve guide bore.

CAUTION

b. Start the reamer straight into the valve guide

When installing oversize valve

bore.

guides, make sure to match each

guide to its respective bore in the cyl-

CAUTION

inder head.

Apply pressure only to the end of the

drive socket. If pressure is applied to

7. Install the new guide using the driver handle and

the T-handle it will result in an uneven

valve guide installation tools. Press or drive the

rough cut and a tapered bore.

guide into the cylinder head until the valve guide in-

stallation tool bottoms out on the cylinder head sur-

c. Apply thumb pressure to the end of the drive

face. When the tool bottoms on the cylinder head

socket portion of the T-handle while rotating

surface, the valve guide is installed to the correct

the T-handle clockwise. Only light pressure is

height. If the driver handle tool is not used, install

required. Apply additional lubricant onto the

the valve guide to the same height recorded prior to

reamer and into the valve guide while rotating

removing the valve guide; measure the valve

the reamer.

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ENGINE

131

duced during the honing operation. Repeat this step

108

until all of the valve guides are thoroughly cleaned.

Then rinse the cylinder head and valve guides in

clear, cold water and dry with compressed air.

12. After cleaning and drying the valve guides, ap-

ply clean engine oil to the guides to prevent rust.

13. Resurface the valve seats as described in Valve

Seat Reconditioning in this chapter.

Valve seat width

Valve Seat Inspection

1. Remove all carbon residue from each valve seat.

Then clean the cylinder head as described under

Valve Inspection in this chapter.

NOTE

The most accurate method of check-

Continue to rotate the reamer until the entire

ing the valve seat width and position

bit has traveled through the valve guide and

is with machinist’s dye.

the shank of the reamer rotates freely.

2. Check the valve seats in their original locations

CAUTION

with machinist’s dye as follows:

Never back the reamer out through

a. Thoroughly clean the valve face and valve

the valve guide as the guide will be

seat with contact cleaner.

damaged.

b. Spread a thin layer of Prussian blue or ma-

Remove the T-handle from the reamer. Re-

chinist’s dye evenly on the valve face.

move the reamer out from the combustion

c. Insert the valve into its guide.

chamber side of the cylinder head.

d. Support the valve by hand (Figure 107) and

Apply low-pressure compressed air and clean

tap the valve up and down in the cylinder

out the small shavings from the valve guide

head. Do not rotate the valve or a false read-

bore. Then clean the valve guide bore with the

ing will result.

small spiral brush.

e. Remove the valve and examine the impres-

Hone the valve guide as follows:

sion left by the machinist’s dye. The impres-

a. Install the valve guide hone into a high-speed

sions on the valve and the seat must be even

electric drill.

around their circumferences and the width

b. Lubricate the valve guide bore and hone

(Figure 108) must be within the specifica-

stones with the reamer lubricant—do not use

tions in Table 2. If the width is beyond the

motor oil.

specification or if the impression is uneven

c. Carefully insert the hone stones into the valve

recondition the valve seats.

guide bore.

3. Closely examine the valve seat in the cylinder

d. Start the drill and move the hone back and

head (Figure 93). It must be smooth and even with a

forth in the valve guide bore for 10 to 12 com-

polished seating surface.

plete strokes. Work for a 60° crosshatch pat-

4. If the valve seat is in good condition, install the

tern.

valve as described in this chapter.

5. If the valve seat is not correct, recondition the

10. Repeat for each valve guide.

valve seat as described in this chapter.

11. Soak the cylinder head in a container filled with

hot, soapy water. Then clean the valve guides with a

valve guide brush or an equivalent bristle

Valve Seat Reconditioning

brush—do not use a steel brush. Do not use clean-

ing solvent, kerosene or gasoline as these chemicals

Valve seat reconditioning requires considerable

will not remove all of the abrasive particles pro-

expertise and special tools. In most cases it is more

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132

CHAPTER FOUR

economical and practical to have these procedures

performed by an experienced machinist.

109

The following procedure is provided for those

equipped to perform the task. A valve seat cutter set

(HD-35758A) or equivalent is required. Follow the

manufacturer’s instructions.

Refer to Figure 109 for valve seat angles. While

Cylinder head

the valve seat angles for both the intake and exhaust

valves are the same, different cutter sizes are re-

Seat

quired. Also note that a 45-degree seat angle is

Valve

specified when grinding the seats, while a

60°

46-degree seat angle is specified when cutting seats.

0.040-0.062 in.

1. Clean the valve guides as described under In-

(1.02-1.57 mm)

spection in this chapter.

2. Carefully rotate and insert the solid pilot into the

valve guide. Make sure the pilot is correctly seated.

31°

46° cutting

45° grinding

Margin

CAUTION

Valve seat accuracy depends on a cor-

rectly sized and installed pilot.

3. Using the 45-degree grinding stone or 46-degree

cutter, descale and clean the valve seat with one or

two turns.

8. Reinsert the solid pilot into the valve guide. Be

certain the pilot is properly seated. Install the 31°

CAUTION

cutter onto the solid pilot and lightly cut the seat to

Measure the valve seat contact area in

remove 1/4 of the existing valve seat.

the cylinder head (Figure 108) after

each cut to make sure its size and area

9. Install the 60° cutter onto the solid pilot and

are correct. Over-grinding will sink

lightly cut the seat to remove the lower 1/4 of the

the valves too far into the cylinder

existing valve seat.

head, requiring replacement of the

10. Measure the valve seat with a vernier caliper.

valve seat.

Then fit the 45° grinding stone or 46° cutter onto the

4. If the seat is still pitted or burned, turn the cutter

solid pilot and cut the valve seat to the specified seat

until the surface is clean. Work slowly and carefully

width in Table 2.

to avoid removing too much material from the valve

11. When the valve seat width is correct, check

seat.

valve seating as follows.

5. Remove the pilot from the valve guide.

12. Remove the solid pilot from the cylinder head.

6. Apply a small amount of valve lapping com-

13. Inspect the valve seat-to-valve face impression

pound to the valve face and install the valve. Rotate

as follows:

the valve against the valve seat using a valve lap-

a. Clean the valve seat with contact cleaner.

ping tool. Remove the valve.

7. Measure the valve seat with a vernier caliper

b. Spread a thin layer of Prussian Blue or ma-

(Figure 108 and Figure 109). Record the measure-

chinist’s dye evenly on the valve face.

ment to use as a reference point when performing

c. Insert the valve into its guide.

the following.

d. Support the valve with two fingers and turn it

with the valve lapping tool.

CAUTION

The

31° cutter removes material

e. Remove the valve and examine the impres-

quickly. Work carefully and check the

sion left by the Prussian blue or machinist’s

progress often.

dye.

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ENGINE

133

Valve Lapping

110

If valve wear or distortion is not excessive, at-

tempt to restore the valve seal by lapping the valve

to the seat.

After lapping the valves, install the valve assem-

Port

blies and test each valve seat for a good seal by

pouring solvent into the ports (Figure 110). If the

Solvent

seal is good, no solvent will leak past the seat sur-

kerosene

face. If solvent leaks past any seat the combustion

chamber will appear wet. Disassemble the leaking

valve and repeat the lapping procedure or recondi-

tion the valve as described in this chapter.

1. Smear a light coating of fine grade valve lapping

compound on the seating surface of the valve.

2. Insert the valve into the head.

3. Wet the suction cup of the lapping tool and stick

Combustion

it onto the head of the valve. Lap the valve to the

Valve

chamber

seat by spinning the tool between both hands while

lifting and moving the valve around the seat 1/4 turn

at a time.

4. Wipe off the valve and seat frequently to check

the progress. Lap only enough to achieve a precise

f. Measure the valve seat width (Figure 108 and

seating ring around the valve face.

Figure 109). Refer to Table 2 for the correct

5. Closely examine the valve seat in the cylinder

seat width.

head. The seat must be smooth and even with a pol-

g. The valve seat contact area must be in the

ished seating ring.

center of the valve face area.

6. Thoroughly clean the valves and cylinder head

14. If the contact area is too high on the valve, or if

in solvent to remove all grinding compound resi-

it is too wide, cut the seat with the 31° cutter. This

due. Compound left on the valves or the cylinder

will remove part of the top valve seat area to lower

head will cause rapid engine wear.

or narrow the contact area.

7. After installing the valves into the cylinder head,

15. If the contact area is too low on the valve, or

test each valve for proper seating. Check by pouring

if it is too wide, use the 60° cutter and remove part

solvent into the intake and exhaust ports. Solvent

of the lower area to raise and narrow the contact

must not leak past the valve seats. If leakage occurs,

area.

the combustion chamber will appear wet. If solvent

16. After obtaining the desired valve seat position

leaks past any of the seats, disassemble that valve

and angle, use the 45° grinding stone or the 46° cut-

assembly and repeat the lapping procedure until

ter and very lightly clean off any burrs caused by the

there is no leakage.

previous cuts.

17. When the contact area is correct, lap the valve

Valve Seat Replacement

as described in this chapter.

18. Repeat Steps 1-17 for the remaining valve

Valve seat replacement requires considerable ex-

seats.

perience and equipment. Refer this work to a

19. Thoroughly clean the cylinder head and all

Harley-Davidson dealership or machine shop.

valve components in solvent, then clean with deter-

gent and hot water and rinse in cold water. Dry with

compressed air. Then apply a light coat of engine oil

CYLINDER

to all non-aluminum metal surfaces to prevent rust

formation.

Refer to Figure 111.

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134

CHAPTER FOUR

111

PISTON/CYLINDER BLOCK ASSEMBLY

1. Upper compression ring

2. Lower compression ring

3. Upper oil ring

4. Spacer

5. Lower oil ring

6. Retaining ring

7. Piston

8. Connecting rod bushing

9. Connecting rod

10. Piston pin

11. O-ring

12. Locating dowel

13. Cylinder block

14. O-ring seal

Removal

112

1. Remove the cylinder head as described in this

chapter.

2. Remove all dirt and debris from the cylinder base.

3. If still in place, remove the two dowel pins and

O-rings (Figure 112) from the top of the cylinder

block.

4. Turn the crankshaft until the piston is at bottom

dead center (BDC).

NOTE

The front and rear cylinder blocks are

identical (same part number). Mark

each cylinder block so they will be re-

installed in their original positions.

113

5. Pull the cylinder straight up and off the piston and

cylinder studs. If necessary, tap around the perimeter

of the cylinder with a rubber or plastic mallet.

6. Place clean shop rags (A, Figure 113) into the

crankcase opening to prevent objects from falling

undetected into the crankcase.

7. Remove the O-ring seal (B, Figure 113) from

the locating dowel. Leave the locating dowels in

place unless they are loose.

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ENGINE

135

8. Remove the O-ring (Figure 114) from the base

114

of the cylinder.

9. Install a vinyl or rubber hose over each stud

(Figure 115). This will protect both the piston and

the studs from damage.

CAUTION

After removing the cylinder, use care

when working around the cylinder

studs to prevent bending or damaging

them. The slightest bend could cause

the stud to fail.

10. Repeat these steps to remove the other cylinder.

115

Inspection

To obtain an accurate cylinder bore measure-

ment, the cylinder must be torqued between torque

plates. Measurements made without the torque

plates will be inaccurate and may vary by as much

as 0.001 in. (0.025 mm). Refer this procedure to a

shop equipped and experienced with this procedure

if the tools are not available.

The torque plates (Figure 116) shown in this proce-

dure are JIMS Cylinder Torque Plates (part No. 1287).

The cylinder block bore must be thoroughly clean

to obtain accurate measurements. The cylinder

116

must be at room temperature to obtain accurate

measurements. Do not measure the cylinder imme-

diately after it has been honed, as it will still be

warm. Measurements can vary by as much as 0.002

in. (0.051 mm) if the cylinder block is not at room

temperature.

1. Thoroughly clean the outside of the cylinder.

Use a stiff brush, soap and water and clean all debris

from the cooling fins (Figure 117). If necessary, use

a piece of wood and scrape away any lodged dirt.

Clogged cooling fins can cause overheating leading

to possible engine damage.

117

2. Carefully remove all gasket residue from the top

and bottom cylinder block gasket surfaces.

3. Thoroughly clean the cylinder with solvent and

dry with compressed air. Lightly oil the cylinder

block bore to prevent rust.

4. Check the top and bottom cylinder gasket sur-

faces with a straightedge and feeler gauge (Figure

118). Replace the cylinder if warp exceeds the limit

in Table 2.

5. Check the cylinder bore (Figure 119) for scuff

marks, scratches or other damage.

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136

CHAPTER FOUR

6. Install the torque plate onto the cylinder (Figure

120) following the manufacturer’s instructions.

118

7. Measure the cylinder bore with a bore gauge or

inside micrometer (Figure 121) at the positions in-

dicated in Figure 122. Perform the first measure-

ment 0.500 in. (12.7 mm) below the top of the

cylinder (Figure 122). Do not measure areas where

the rings do not travel.

8. Measure in two axes-aligned with the piston pin

and at

90 degrees to the pin. If the taper or

out-of-round measurements exceed the service lim-

its in Table 2, bore both cylinders to the next over-

size and install oversize pistons and rings. Confirm

the accuracy of all measurements and consult with a

119

parts supplier on the availability of replacement

parts before having the cylinder serviced.

9. Remove the torque plates.

10. If the cylinders were serviced, wash each cylin-

der in hot, soapy water to remove the fine grit mate-

rial left from the boring or honing process. After

washing, run a clean white cloth through the cylin-

der bore. If the cloth shows traces of grit or oil, the

bore is not clean. Repeat until the cloth passes

through cleanly. When the bore is clean, dry with

compressed air, then lubricate with clean engine oil

to prevent the bore from rusting.

CAUTION

120

The use of hot soapy water is the only

procedure that will completely clean

the cylinder bore. Solvent and kero-

sene cannot wash fine grit out of the

cylinder crevices. Abrasive grit left in

the cylinder will cause premature en-

gine wear.

Cylinder Studs and Cylinder Head Bolts

Inspection and Cleaning

The cylinder studs and cylinder head bolts must

be in good condition and properly cleaned prior to

installing the cylinder blocks and cylinder heads.

121

Damaged or dirty studs may cause cylinder head

distortion and gasket leakage.

CAUTION

The cylinder studs, cylinder head

bolts and washers consist of hardened

material. Do not substitute these

items with a part made of a lower

grade material. If replacement is re-

quired, purchase the parts from the

manufacturer.

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ENGINE

137

1. Inspect the cylinder head bolts. Replace any that

122

are damaged.

2. Examine the cylinder studs (A, Figure 123) for

bending, looseness or damage. Replace studs as de-

scribed under Cylinder Stud Replacement in this chap-

ter. If the studs are in good condition, perform Step 3.

3. Cover both crankcase openings with shop rags

(B, Figure 123) to prevent debris from falling into

the engine.

4. Remove all carbon residue from the cylinder

studs and cylinder head bolts as follows:

a. Apply solvent to the cylinder stud and mating

cylinder head bolt threads and thread the bolt

onto the stud.

b. Turn the cylinder head bolt back and forth to

loosen and remove the carbon residue from

the threads. Remove the bolt from the stud.

Wipe off the residue with a shop rag moist-

ened in cleaning solvent.

c. Repeat until both thread sets are free of all

carbon residues.

d. Spray the cylinder stud and cylinder head bolt

with an aerosol parts cleaner and allow them

to dry.

e. Set the cleaned bolt aside and install it on the

same stud when installing the cylinder head.

5. Repeat Step 4 for each cylinder stud and cylinder

123

head bolt set.

Installation

NOTE

If installing a cylinder block that has

been bored oversize, the inner

lead-in angle at the base of the bore

skirt

(Figure 124) has been elimi-

nated. This lead-in angle is neces-

sary so the piston rings can safely

enter the cylinder bore. If necessary,

use a chamfering cone (JIMS part

124

No. 2078) or a hand grinder with a

fine stone and grind in a new lead-in

angle. The finished surface must be

smooth so it will not catch and

damage the piston rings during instal-

lation.

1. If removed, install the pistons and rings as de-

scribed in this chapter.

2. Remove all gasket residue and clean the cylinder

block as described under Inspection in this chapter.

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138

CHAPTER FOUR

3. Remove the vinyl or rubber hose from each stud

(A, Figure 125).

125

4. Install a new O-ring onto the base of the cylinder

block. Apply a light coat of clean engine oil to the

O-ring.

5. If removed, install the locating dowels (Figure

126) into the crankcase.

6. Install a new O-ring seal (B, Figure 113) onto

the locating dowel. Apply a light coat of clean en-

gine oil to the O-ring.

7. Turn the crankshaft until the piston is at top dead

center (TDC).

8. Lubricate the cylinder bore, piston and piston

rings liberally with clean engine oil.

126

9. Position the top compression ring gap so it is fac-

ing the intake port. Then stagger the remaining pis-

ton ring end gaps so they are 90 to 180° from the gap

of the ring above it (Figure 127).

10. Compress the piston rings with a ring compres-

sor (B, Figure 125).

NOTE

Install the cylinder in its original po-

sition as noted during removal.

11. Carefully align the cylinder (front facing for-

ward) with the cylinder studs and slide it down

127

(Figure 128) until it is over the top of the piston.

Then continue sliding the cylinder down and past

the rings (Figure 129). Remove the ring compres-

sor once the piston rings enter the cylinder bore. Re-

move the shop rag from the crankcase opening.

12. Continue to slide the cylinder down until it bot-

toms out on the crankcase.

13. Repeat to install the other cylinder.

14. Install the cylinder heads as described in this

chapter.

PISTONS AND PISTON RINGS

Refer to Figure 111.

Removal

1. Remove the cylinder as described in this chapter.

2. Cover the crankcase with clean shop rags.

3. Lightly mark the pistons with a F (front) or R

(rear) (A, Figure 130).

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ENGINE

139

128

132

Pad

Nut

Pipe

Washer

Threaded

rod

129

133

WARNING

130

The piston pin retaining rings may

spring out of the piston during re-

moval. Wear safety glasses when re-

moving them in Step 4.

4. Using an awl, pry the piston pin retaining rings

(Figure 131) out of the piston. Place a thumb over

the hole to help prevent the rings from flying out

during removal.

NOTE

Mark the piston pins so they can be

reinstalled into their original pis-

tons.

131

5. Support the piston and push out the piston pin

(B, Figure 130). If the piston pin is difficult to re-

move, use a piston pin removal tool (Figure 132).

6. Remove the piston from the connecting rod.

7. Remove the piston rings using a ring expander

tool (Figure 133) or spread them by hand (Figure

134) and remove them.

8. Inspect the pistons, piston pins and pistons rings

as described in this chapter.

Harley Davidson 1999-2005 Harley Dyna Models. Repair Manual - page 7