This is an old revision of the document!


IH: Carburetor, Intake Manifold & Exhaust

See also Installation of Top End for proper alignment of intake manifold.


Intake Manifold

HD Sportster Manifold Part Numbers
Year ModelManifold Part#MaterialThroat Dia.Bolt Hole
Dims/Spacing
OEM Carb
1957-1971 Sportsters27021-57Cast iron1.562“.39” holes on a 2.688“ b.c. 1)Linkert
Tillotson
1972-1974 Sportsters27021-71Cast iron1.562”.33“ holes on 2.750” b.c. 2)Bendix / Zenith
1975-1979 Sportsters27021-71AAluminum1.562“.33” holes on a 2.750“ b.c. 3)Bendix / Zenith
Keihin “butterfly”
1980-1985 Sportster27021-78 4)Aluminum Keihin “butterfly”
HD Big Twin Manifold Part Numbers
Year ModelManifold Part#
1971-1975 FL/FLH/FX27021-71 5)
1976-E1980 FL/FX27021-71A 6) 7)
L1980-later FX27021-788)
1972-1974 Sportster Intake Manifold (27021-71) 9)
1975-1979 Sportster Intake Manifold (27021-71A) 10)


Click Here to go to the TSB page in the Sportsterpedia and download TSB M-788 regarding the changes for the 27021-78 manifold.
In March, 1980, several modifications were made to heads/intake manifolds/clamps used on L1980 1200/1340cc FL/FX models to improve sealing capabilities.

1980-1985 Sportster Intake Manifold (27021-78) 11)

Seals - Intake to Heads

Intake to Head - Hardware History. 12) 13) 14) OEM Part Numbers
1957-78 Used exact same port sealing machining, heads and manifolds Uses O-rings - 27060-55 - Clamp 27063-57
1979 Confusing because it had the o-ring machining but used rubber bands Uses rubber bands - 27062-78 - Clamp 27063-78
E1980 Dropped the machining for the O-ring Uses rubber bands - 27062-78 - Clamp 27063-78
L1980-1985 Uses same rubber bands as 79-E80 but different clamp Uses ruber bands - 27062-78 - Clamp 27063-80
1979 models could retro fit 78-earlier interface mechanisms as a bolt on mod.
1980-later models needed the heads to be machined for reverting to the straight up o-ring seals.
1957-1978 Intake Manifold O-rings (27060-55) 15) 1957-1978 Intake Manifold Clamp (27063-57) 16)
1979-1985 Sportster Intake Manifold
Rubber Bands (27062-78) 17)
1979-E1980 Intake Manifold Clamp (27063-78) 18)

Bendix

Keihin Butterfly

These V-twin clamps (35-0419) work well for stopping intake leaks. The tool to install them is the same as any oiteker clamp pliers. 23)
24) 25)

4)
1979-1985 HD Sportster Parts Catalog
5)
HD 1961-1976 ElectraGlide/SuperGlide Parts Catalog pg 19
6)
HD 1941-1978 ElectraGlide/SuperGlide Parts Catalog pg 17
7)
HD 1971-1980 FX/SuperGlide Parts Catalog pg 25
8)
HD 1971-1984 FX Parts Catalog pg 29
9)
photos courtesy of Stripped Down Cycles Link to Ebay Store:
10)
photos courtesy of Ebay seller, animalhouse2010, Link to Ebay store:
11)
photos courtesy of Ebay seller, Robison Motorcycles Link to Ebay Store
12)
See Brucstoudt & Dr_Dick - XLForum - http://xlforum.net/forums/showthread.php?t=2079889
14)
1979-1985 HD Sportster Parts Catalog pgs 23-27
15) , 17)
photo courtesy of Ebay seller, jrsvintageharley1990. Link to Ebay Store
16) , 18)
photos courtesy of Ebay seller, jrsvintageharley1990. Link to Ebay Store
19) , 20) , 21) , 22)
photo by The Doctor71 of the XLFORUM http://xlforum.net/forums/showthread.php?t=2071371
This website uses cookies for visitor traffic analysis. By using the website, you agree with storing the cookies on your computer.More information