S&S Cycle - S&S Performance Parts 2025 L - Volume 67

Appendix

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S&S® flywheels are manufactured in sets only We do not sell individual right or left flywheels, nor do we recommend mixing flywheels This is because the manufacturing techniques and/or tooling changes periodically To prevent mixing flywheels, as well as to identify each set, the right and left flywheels are stamped with identical serial numbers (see picture) Serial Number Identification Information Serial Number ID , B01810-3SLX , deciphered as follows: Serial Number: From this number , S&S can determine when the flywheels were made and sold , to whom they were sold , and how the flywheels were originally balanced

1 -2017-UP 2- 2007-'17 3 -1999-'06 4 -1984-'99 5 -1936-'84 6 -XL-RA1250 7 -BELTS & GASKETS 8 -TOOLS 9 -WARRANTY 10 -APPENDIX 1 2 3 4 5 6 9 12 13 14 16 17 18 19 1 2 6 TB 1 2 3 4 6 7 8 9 11 12 15 16 17 18 19

(B01810) (3) (SL)

Stroke Code: Determines the stroke of the flywheels In this case the stroke is 43/4” Year Code: The year of the engine the flywheels were machined to fit and that the flywheels were machined to accept an S&S design sprocket shaft Diameter Code: Diameter of the flywheels In this case the diameter is 81/4”

Flywheel Serial Number

S&S® Flywheel Identification Codes For 1936–Up Big Twin Stroke Code Stroke Year Code Engine Year

Sprocket Shaft

Pinion Shaft Crankpin Type

Diameter Code Flywheel Diameter

43⁄8" 41⁄2" 43⁄4"

E L

1936–'54 1955–'71

Stock

Stock Stock Stock Stock Stock Stock

1941–'81 or Press In None 1941–'81 or Press In A

81⁄2" (Stock)

Stock or Intrical

83⁄8" 81⁄4"

AL SE BL SL

1972–Early '81 1955–Early '81 Late 1981–'99 Late 1981–'99

Stock

1941–'81 1941–'81 1981–'99

X

5"

S&S

41⁄4" (Stock 80")

Stock

45⁄8"

S&S or Intrical

1981–'99 or Press In Press In or Intrical

Special order

SF or SF3

1999–up

Press In

Press In Press In

51⁄4"

SG SM

S&S 41/8" Bore Evolution Press In

Press In

31⁄2" (Stock 61") 331⁄32" (Stock 74")

1995–'99 EFI

Press In

S&S

1981–'99

Y

74"/80" Indian®

Stock

Stock

Stock

51⁄8"

4”

35⁄8" 41⁄8" 43⁄8" 41⁄2" 45⁄8”

M8 M8 M8

2017-Up 2017-Up 2017-Up

Integral Integral Integral

Integral Integral Integral

4 450”

S&S® Fly Wheel Identification Codes For Harley-Davidson® Sportster® & Buell® Models Stroke Code Stroke Year Code Engine Year Shaft Flywheel Codes: Codes that pertain to the most common regular production flywheels have been listed Many other codes for racing flywheels and special orders also exist If you have a question about a set of S&S flywheels with codes different than those shown, contact an S&S technical assistant to properly identify what you have Flywheel ID codes that end with an“A”or an“X”designate flywheels with a smaller than stock diameter Stock big twin flywheels measure 8 1/2”, and stock flywheels for Harley-Davidson® Sportster® models are 7 7/8”in diameter Typically, “A”means 1/8” smaller, and “X”means 1/4”smaller To verify the code, it is best to measure the flywheels

Flywheel Code Letter

Serial numbers can be seen through the timing hole to identify the stroke of an assembled engine Keep in mind they will appear upside down in the hole

Pinion Shaft Crankpin Type Rod Bearing Type Diameter Code Flywheel Diameter

41/16" 43/16" 45/16" 47/16" 45⁄8" 413/16"

None

1957–'76

Stock

Stock Stock Stock

Stock Stock Stock Stock Stock Stock Stock Stock Stock Stock

Stock Stock Stock Stock Stock Stock Stock Stock

None

77/8" (Stock)

B

1957–Early '81 Stock 1957–Early '81 S&S 1957–Early '81 Stock 1977–Early '81 S&S Late 1981–'85 Stock Late 1981–'85 S&S Late 1981–'85 S&S Late 1981–'85 S&S Late 1981–'85 S&S Late 1986–’03 S&S Late 1986–’03 S&S S&S Prostock Press In

A X

73⁄4" 75⁄8"

SB BD

SBD

C* SC

Stock Stock

5"

Special Order SCD

41/2" 51⁄4"

SCR

Stock

1987–Up 1987–Up

SCDR

313/16”

D

S&S S&S

S&S S&S

S&S

51⁄8"

DR PS

1987–Up

4"

Press In

Press In

35/8" 41/8"

KRS

45" WR/KR 45" Indian

Stock Stock

Stock Stock

1957–'81 XL

1957–'81 XL

YS

Stock

Stock

10-4

* Obsolete – S&S no longer makes this design