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IH: Engine Mechanicals

See also Crankshaft / Flywheel Tools in the Reference section of the Sportsterpedia.

Sub-Documents

Engine Cases

Year ModelCase Set
Part#
Left Case
Part#
Left Case
Casting#
Right Case
Part#
Right Case
Casting#
1957-1965 XL/XLH24511-5724532-5724534-5724556-5724558-57
Notes“No hump” cases (primary not cast for electric start)
1958-1965 XLC/XLCH24515-5824532-5824534-5724556-5724558-57
Notes“No hump” cases (primary not cast for electric start).
1966 XLH24511-57
24511-57A
24532-5724534-5724555-57
24555-57A
24558-57
Notes “No hump” cases (primary not cast for electric start).
E1966 case set (24511-57) replaced by (24511-57A) on 1-13-1966
Factory changes made starting with crankcase# (66 XLCH 6117-up); 1)
Right case has fillet added to base of countershaft low gear boss.
Right case is replacement for all 1957-1965 models.
-57A case set is replacement for 57-66 XL/XLH (24511-57)
Left case is replacement for 1957-1966 XL/XLH
Case set (24511-57A) replaced by 1969 XLCH case set (24515-58A) in 1969
Left case replaced by XLCH (24532-58) in 1969 for 57-66 XL/XLH
1966-1969 XLCH24515-58
24515-58A
24532-5824534-5724555-57
24555-57A
24558-57
Notes“No hump” cases (primary not cast for electric start).
E1966 case set (24515-58) replaced by (24515-58A) on 1-13-1966
Factory changes made (66 XLCH 6117-up); 2)
Right case has fillet added to base of countershaft low gear boss.
-57A right case is replacement for all 1957-1965 models
-58A case set is replacement for 1966 XLH in 1969
1967-1968 XLH24512-6724531-6734-6724555-6724558-67
Notes“Hump” cases (primary cast to accept electric starter)
1969 XLH24512-67A24532-5834-6724555-67A24558-67
Notes“Hump” cases (primary cast to accept electric starter).
Right case is replacement for 1967-1968 XLH
Case set is also replacement for 1967-1969 XLH
1970-1971 XLH/XLCH24512-67A24531-6734-6724555-67A24558-67
Notes1970 and all future years are “hump” cases for electric start
Left case is replacement for 1967-1969 XLH
Right case is replacement for 1967-1969 XLH
Case set is also replacement for 1967-1969 XLH
1978 parts supplement corrects “used on” models to 70-71 XLCH
VIN moved the from the left side case to the right case.
A blank Vin pad is still on the left with no number stamped on it. 3)
1971 XLCH24512-7024531-67 24555-70
NotesCase set is also replacement for 1970 XLCH. Possible one year only case set (see above)
1972 XLH/XLCH24505-7224535-7224534-7224551-7224558-72
NotesFirst year for 1000 Sportsters. Last year of the speedometer drive gear in the right case.
1973-1976 XLH/XLCH24505-7324535-7324534-7224551-7324558-73A
NotesThere was a late 1973 cylinder and head change but the crankcase was left unchanged 4)
Starting in 1976, case halves not sold separately
1977-1978 XL/XLCH/XLCR24527-75 - 24534-75 - 24558-75
NotesCases redesigned for a minisump, new oil pump mounting boss, left side shifter
Crankcase breathes thru holes in gearcase wall, oil trough for timed breather deleted.
Vertical oil scavenge passage drilled in sump wall
1979 XL/XLCH24527-75A - 24534-75 - 24558-75
NotesRight case modified to eliminate high pressure oil leakage around the oil passage between the
upper crankcase cover and crankcase in November, 1979 5)
1979-1980 XLS24490-79A - 24534-75 - 24558-75
NotesLast year cases were cast with hole for kick start.
1980 XL24527-75B - 24534-75 - 24558-75
NotesCase set is also replacement for 1979 XL/XLCH.
1981-1982 XL24527-81A - 24534-81 - 24558-75A
NotesSold for 1982-E1984 XL/XLS/XLX in 1985
Must use rear motor mount 16203-82A
L1981 to E1982 production change on the right case, all XL models.
On some cases, the oil galley slot in the top of the gearcase was not machined.
Instead, a hole was drilled thru to connect the oil path.
Upper left corner of gearcase also received additional threaded hole to mount the gearcase cover.
Left case has a new “hump” casting to mount the new Nippon Denso starter.
1981-1982 XLS24490-81A - 24534-81 - 24558-75B
NotesCase set is (painted black). See 1981-1982 XL production change above.
1981-1982 XLS
replacement
24490-81C - -
NotesReplacement (painted black) case for 1981-1982 XLS offered in 1983
Must use rear motor mount 16203-67A on 1981 models
Must use rear motor mount 16203-82A on 1982 and 1983 models
1982 XLS
replacement
24490-82 - -
NotesReplacement (painted black) case for 1982 XLS offered in 1984
Must use rear motor mount 16203-82A
1983 XL/XLS24527-81C - 24534-83 - 24558-83A
NotesReplacement case for 1981-1982 XL offered in 1983
Must use rear motor mount 16203-67A on 1981 models
See TSB M-876A for more details
Must use rear motor mount 16203-82A on 1982 and 1983 models
L1983 production change:
The roll pin for the trans thrust washer in the case was removed. 6)
L1983 XR-100024517-83 - -
Notes
E1984 XL/XLS/XLX24480-84 - 24534-83A - 24558-83B
NotesCase set 24480-84 is listed in 1984 parts book but number was later given to L1984 case set 7)
E1984 XL/XLS/XLX24527-82A - 24534-83A - 24558-83B
NotesLate 1984 production change 8)
Case set is also replacement for 82-E84 models
Must use rear motor mount 16203-82A
New crankcase set starting with crankcase date code 7 84 174011 (June 22, 1984).
Features new mainshaft bearing race (35105-83) and new pressed in mainshaft seal (12049).
Trans mainshaft/roller bearing/retaining ring remain unchanged
Same channel cast into right side of tranny compartment but hole not drilled for stator grommet
L1984 XL/XLS/XLX24480-84 - 24534-83A - 24558-83B
NotesProduction change in 1984
Generator deleted, hole in case there redesigned for oil filter mount
Stator mounted to trap door w/ hole in case for wire grommet
Channel cast into right side of tranny compartment ending in hole for stator wire grommet
1985 XL/XLS/XLX24480-85 - -
NotesOriginally listed for all 1985 models thru the -85 parts book
Sold for Late 1985 thru the -85A parts book
Starting with crankcase# (785 303002) a cam gear oiler was installed
Right case drilled/tapped between F-R tappets for oiler tube feed oil
Gearcase wall tapped to attach oiler tube
E1985 XL/XLS/XLX24480-85A - 24534-83A - 24558-83B
NotesSold for Early 1985 thru the -85A parts book

Flywheel

Sub-Documents

Catalog of OEM Flywheels

Year Model →
Parts ↓
1952-1953
K/KK
1954-1956
K Models
1957-1971
XL/XLH
XLC/XLCH
1972-1976
XLH/XLCH
1977-1979
XLH/XLCH/XLS
full assembly
used until
depleted →
1980-E1981
XL / XLS
full assembly
used until
depleted →
L1981-1985
XL/XLS/XLX
Flywheel Assembly
w/shafts, w/rods
23900-5223900-54
23900-54A
23900-57
23900-57A (72)
23900-57A23900-7523900-75A23900-75B
23900-75C (83)
Left
Flywheel
23915-5223916-54
23916-54A
23916-57
23916-57A (72)
23916-57A23916-57A
Keyway
23916-57A23916-80
No keyway
Right
Flywheel
23935-5223936-54
23936-54A
23936-57
23936-57A (72)
23936-57A23936-57A
Compound
oil path
23936-57A
timing marks
changed
from case#
780-108-001 9)
23936-80
Single line
oil path
Connecting Rod
Assembly
w/bearings
w/crankpin
24275-5224275-5424275-5724275-5724275-5724275-5724275-80
Rear
Rod
24290-5224290-5224290-5724290-5724290-5724290-5724290-57
Front
Rod
24294-5224294-5224294-5224294-5224294-5224294-5224294-52
Crankpin23960-5223960-5423960-5423960-5423960-54
Oil hole 110°
from keyway
23960-5423960-80
w/ plug
Oil hole 90°
from keyway
Crankpin
Roller (std)
(1 roller)
9101 (E52)
9381 (L52-53)
9401 (52-53)
9441
9441A (59)
9150
9150A (59)
9441
9441A (59)
9150
9150A (59)
9441A
9150A
9441A
9150A
9441A
9150A
9441A
9150A
Crankpin Key23985-18
1/8“ x 1/2”
23985-18
1/8“ x 1/2”
23985-18
1/8“ x 1/2”
23985-18
1/8“ x 1/2”
23985-18
1/8“ x 1/2”
23985-18
1/8“ x 1/2”
11218
1/8“ x 3/8”
Crankpin Boss
Washer
23972-5223972-5423972-5723972-7223972-72 (E79)
6506 (L79)
65066506
Crankpin Nut23967-4823967-5423967-54
23967-54A (71)
23967-54A23967-54A
Crankpin Nut
Lock Plate
24015-3624015-36 (E54)
23971-41 (L54)
23971-4123971-4123971-41
Lock Plate
Screw
266926691187 10)
2669 11)
2669W (65)
2669W
Con Rod Rear
Roller Retainer
24362-52
24361-54
24362-5424362-5424362-54A24362-54A24362-54A24362-54A
Con Rod Front
Roller Retainer
24364-52
24361-54
24364-5424364-5424364-54A24364-54A24364-54A24364-54A
Con Rod Rear
Bearing Race
24341-52A (74)24341-52A (74)24341-52A24341-52A24341-52A
Con Rod Front
Bearing Race
24352-52A (74)24352-52A (74)24352-52A (74)24352-52A24352-52A24352-52A
Sprocket Shaft24000-5224000-5424000-5724000-5724000-7524000-75
Large keyway
24000-80 12)
24000-81 13)
common taper
No keyway
Sprocket Shaft Key23985-12
3/16“ x 1/2”
23985-12
E54 KH
40390-54
L54-56
40390-5423985-12
3/16“ x 1/2”
23985-12
3/16“ x 1/2”
23985-12
3/16“ x 1/2”
not used
Gear Shaft24005-5224005-5424005-5724005-5724008-75
-77A, -78
3/16“ key
24008-75A
2-piece 14)
24005-75 15)
24005-80 16)
1-piece 17)
common taper
1/8” key
Gear Shaft Key23985-18
1/8“ x 1/2”
23985-18
1/8“ x 1/2”
23985-12
3/16“ x 1/2”
23985-12
3/16“ x 1/2”
23985-12 (E79)
11200 (L79)
11200 18)11218
1/8“ x 3/8”
Sprocket Shaft
or Gear Shaft
Lock Plate
24015-3624015-36
Lock Plate
Screw
266926691187 19)
2669 20)
2669W (65)
2669W
Sprocket or Gear
Shaft Nut
24003-54
(54-E55)
8011
(54-56)
8011801180118011
Pinion Gear Nut
Tabbed Washer
7913
7044
7913
7044

L1981-up Commonized Flywheels

  • In May of 1981, the MoCo issued a bulletin stating that product and quality improvements have brought about a commonized flywheel taper design.

All tapers were communized at 6° and all keyways were standardized.
In June of 1981, an update to this bulletin was issued to include part numbers. 21) 22)

  • A limited number of E1982 XL engines (782216009-782237017) were assembled without the communized flywheel taper design. 23)
    • Notable component changes are included in the chart below.
    • This was a running change in 1340cc and 1000cc engines but both new and old designs were used in production until the old stock parts ran out.
    • Assembly and disassembly was the same for the old and new style flywheels but the torque values did change for the new style assembly.
      However, new and old style components must not be intermixed.

Changes for Sportster 1000 engines include:

New Flywheel -
Sprocket Side
Gear Side

23916-80
23936-80

'Lazy 8' rear cylinder timing mark and no keyway
Single hole oil path.
The old style flywheel has a keyway on the sprocket side (23916-57A) and a compound (2) hole oil path on the gear side (23936-57A).
New Crankpin23960-80Oil hole is now 90° to the keyway
Old style crankpin (23960-54) oil hole was 110° to the keyway
New Crankpin Nuts23901-8120/1“ thread pattern at 150-185 ft/lbs.
Old style crankpin nuts (23967-54A) were 20/1” threads with 150-175 ft/lbs.
New Sprocket Shaft24000-80No keyway
Old style sprocket shaft (24000-75) has a large keyway
New Sprocket Shaft Nut23902-813/4“ x 20 threads at 100-120 ft/lbs.
Old style sprocket shaft nut (8011) has 11/16” x 18 threads at 100-120 ft/lbs.
New Sprocket Shaft KeyNot used
Old style sprocket shaft key (23985-12) has a large woodruff key (3/16“ x 1/2”)
New Gear Shaft24005-80One piece construction
Old style gear shaft (24008-75A) is of two piece construction
New Gear Shaft Nut23902-813/4“ x 20 threads at 100-120 ft/lbs.
Old style gear shaft nut (8011) has 11/16” x 18 threads at 100-120 ft/lbs.
New Gear Shaft Key11218Small woodruff key (1/8“ x 3/8”)
Old style gear shaft key (11200) has a large woodruff key (3/16“ x 1/2”)
New Crank Key11218Small woodruff key (1/8“ x 3/8”)
Old style crank key (23985-18) has a large woodruff key (1/8“ x 1/2”)

Roller Bearing Inspection (1957-1976)

  • In a letter dated May 9, 1977, an HD interoffice memo was sent regarding an inspection of parts stock roller bearings. Some roller bearing part numbers were found to have incorrect diameters. A new micrometer was purchased to remedy this problem.
  • Two of those part numbers are gear shaft (9421) and crank pin front rollers (9150A) for Sportsters.
  • In light of this oversight, a listing of part numbers with their correct dims and tolerances was issued as in below:
Used for 57-76 Sportster gear shaft roller bearingsDiameterSizeLength
9421.1876“ - 1974”Standard.800“ - .796”
9422.1878“ - 1876”+ .0002“.800” - .796“
9423.1880” - .1878“+ .0004”.800“ - .796
9424.1882” - .1880“+ .0006”.800“ - .796”
9425.1884“ - .1882”+ .0008“.800” - .796“
9426.1886” - .1884“+ .0010”.800“ - .796”
Used for 54-85 Sportster and K Model front crankpin roller bearingsDiameterSize
9150A.1875“ - .1874”Standard.480“
9152A.1877” - .1976“+ .0002”.480“
9154A.1879” - .1878“+ .0004”.480“
9156A.1881” - .1880“+ .0006”.480“
9158A.1883” - .1882“+ .0008”.480“
9160A.1885” - .1884“+ .0010”.480“
9161.1873” - .1872“- .0002”.480“

Primary / Chain Cover

Year ModelPart NumberGasketNotes
1957-1966 XL/XLH34951-5734955-52A
1958-1969 XLC/XLCH34949-5834952-52black
1964-1969 XLCH34949-6434952-52chrome
1967-1970 XLH34947-6734955-67with needle bearing (9063)
1970 XLCH34948-7034955-67
1971 XLCH34948-7134955-67cover replaced by 34949-71 in 1972
1971-1972 XLH/XLCH
1974-1976 XLH/XLCH 24)
34949-7134955-67with needle bearing (9063), polished
1973 XLH/XLCH34949-73 25)34955-67with needle bearing (9063), black
1975-1976 XLH/XLCH34949-75 26) 34955-67
1977 XLH/XLCH34949-75 27)34955-75
1978-1979 XLH/XLCH34956-78 28) 29)34955-75with two needle bearings (9063 x 2)
polished cover from kit (34949-75A)
also replacement for 1977 XLH/XLCH
1979-1980 XLS34941-7934955-75polished
1980 XLH34946-78 30)34955-75polished

Gearcase / Cam Cover

Year ModelCam / Gearcase Cover
Part Number
Gasket
1952-1956 K Models25200-5225224-52
25244-52A
(1977 part #)
1954-1956 KH25200-52A (1963 part #)
1957-1962 XL/XLH/XLCH25200-57
25200-63A (1968 part #)
1963-1966 XLH/XLCH
1967-1969 XLCH
25200-63
25200-63A (1968 part #)
1967-1970 XLH25201-67
25201-67A (1969 part #)
1970 XLCH25200-70
1971-1972 XLH25201-71
1971-1972 XLCH25200-71
1973-1974 XLH25201-73
black
1973-1974 XLCH25200-73
black
1975-1976 XLH25211-75
1975-1976 XLCH25205-75
1977-1978 XL25201-75
1977-1978 XLCH25200-75
25201-75 (1978 parts sup)
25244-52A
1979- XL25201-79
1979- XLCH25200-79
1980 XL25208-80
black
1980 XLS25209-80
polished
E1981 XL25227-81
polished
E1981 XLS25229-81
black
L1981-1982 XLS25209-81
black
25263-81
'82 part# change
L1981-E1984 XL
1983-E1984 XLS/XLX
25208-81
polished
L1984 XLX25207-84
alum. finish
L1984 XL/XLS25208-84
polished
1985 XLX25207-84A
black
1985 XL/XLS25208-84A
polished

1957-1967 XLs had the solid bar cam cover. 31)
1968-1970 had the finned looking cam cover.
You can interchange the covers if you are not concerned about the look of a stocker for your year bike (better resale trying to stay stock). Also be aware that some covers had the round cut out for the electric starter XLH that came out in 1967.
You can slap a cover on and wing it, BUT the proper way is to have the cover line reamed when the motor is apart.
(so the cam cover and the right case half are a match in tolerances.

52-78 cover had only one breather port at 6:00. 32)
79-85 had two. One at 6:00 and one at 10:00.
52-76 uses .625” pinion bushing bore.
77-85 uses .562“ pinion bushing bore.

1952-1956 Cam Cover - casting: 25202-52 33) 1957-1962 Cam Cover - casting: 25202-52A 34) 1963-1967 Cam Cover - casting: 25202-52A35)
1968-1970 Cam Cover - casting: 02-68 36) 1971-1976 Cam Cover - casting: 25202-71 37) 1977-1978 Cam Cover - casting 76-25202F 38)
1979-1980 Cam Cover - casting: 79-25202 39) 1981 Cam Cover - casting: 81-25223 40) L1984-1985 Cam Cover - casting: 25222-84A 41)
(no date code below casting)

Cam Cover Bushings

Oil Deflector / Separator Bushing Assembly (57-62): (or spring loaded top hat)

Looking at the brass part, you can see how the spring catches on the inward bent tabs. There are also unbent tabs on the brass. 42)
These, when bent outward just a little, fit into slots on the far side of the steel bushing pressed into cam cover.
Here's how the factory assembled this thing.
They had pre-assembled the brass to the steel before the steel was pressed into the cover.
Then dropped the spring into the cover and pressed the brass/steel assembly into the cover as a unit (and manipulated the spring to sit correctly if needed).
However, it is possible to assemble the unit without removing the steel from the cover. 43)
You can bend the tangs out without having to remove the steel bush with a screwdriver and a hammer to bend the 2 locating tabs out.
Notes:
The tabs must be bent outward enough that the brass stays keyed to the steel at full spring compression.
You don't want the brass hat to 'unkey' when the generator compresses spring. The brass needs to be able to 'plunge' in and out under the spring pressure once the tags are bent.
If you get too aggressive, you can cause deformations in the brass that allow it to hang up in it's sliding fit to the steel.
These outward bent tangs do 2 things.

  • They keep the brass hat and spring captive in the cover upon generator removal.
  • More importantly, they key the brass to the steel to prevent the brass from rotating with the generator gear.
    The brass is unable to rotate by the tangs keying into the slots.

Inspection:
Check the operation of the oil separator bushing assembly.
The spring should have free action and be fully extended in the gearcase cover.

44) 45)

46) 47) 48)

Crankcase Oil Strainer

  • If you've split the cases and the screen is in good shape, you don't have to take it out. Hit it with some compressed air and see if it needs replacing. 49)

50) 51)
The strainer is held in place by this pin. It is staked into place with the two horizontal lines radiating from the it. To remove strainer, you must first remove the pin. Tear the screen from the strainer and place pliers on the pin inside (the now destroyed strainer) and wiggle the pin out. Strainers and strainer gaskets are available for replacement. 52)


1) , 2)
TSB# 537 dated March 22, 1966
4)
TSB# 652 dated July 30, 1973
5)
TSB M-778 dated May 13, 1980
6)
TSB m-870 dated April 15, 1983
7)
correction noted in Parts and Accessories Bulletin #213 dated January 10, 1984
8)
TSB M-872 dated August 18, 1983
9)
TSB M-781 dated May 23,1980
10) , 19)
1957 parts catalog
11) , 20)
1958 parts catalog supplement
12)
1980 parts catalog
13) , 14) , 16) , 17) , 18)
TSB M-829 dated 5-19-1981
15)
HD 1979-1982 Parts Catalog pg 11
21)
HD Service Bulletin #M-829 dated May 19, 1981
22)
HD Service Bulletin #M-829A dated June 12, 1981
23)
HD Service Bulletin #M-840 dated October 2, 1981
24) , 25)
1974 Sportster Parts Catalog Supplement
26)
1975 Sportster Parts Catalog Supplement
27)
1977 Sportster Parts Catalog Supplement
28)
1978 Sportster Parts Catalog Supplement
29)
1978 Sportster -78A Parts Catalog
30)
1980 Sportster Parts Catalog
34)
photo by ironheadjunkie of the XLFORUM http://xlforum.net/forums/showthread.php?t=1421916&page=2
44) , 45) , 46) , 47) , 48)
photo by 62 Ironhead of the XLFORUM http://xlforum.net/forums/showthread.php?t=1861965
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