Table of Contents
IH: Carburetor, Intake Manifold & Exhaust
See also Installation of Top End for proper alignment of intake manifold.
Intake Manifold
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HD Sportster Manifold Part Numbers | |||||
Year Model | Manifold Part# | Material | Throat Dia. | Bolt Hole Dims/Spacing | OEM Carb |
1957-1971 Sportsters | 27021-57 | Cast iron | 1.562“ | .39” holes on a 2.688“ b.c. 1) | Linkert Tillotson |
1972-1974 Sportsters | 27021-71 | Cast iron | 1.562” | .33“ holes on 2.750” b.c. 2) | Bendix / Zenith |
1975-1979 Sportsters | 27021-71A | Aluminum | 1.562“ | .33” holes on a 2.750“ b.c. 3) | Bendix / Zenith Keihin “butterfly” |
1980-1985 Sportster | 27021-78 4) | Aluminum | Keihin “butterfly” | ||
HD Big Twin Manifold Part Numbers | |||||
Year Model | Manifold Part# | ||||
1971-1975 FL/FLH/FX | 27021-71 5) | ||||
1976-E1980 FL/FX | 27021-71A 6) 7) | ||||
L1980-later FX | 27021-788) |
1972-1974 Sportster Intake Manifold (27021-71) 9) | ||
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1975-1979 Sportster Intake Manifold (27021-71A) 10) | ||
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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) | ||
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Seals - Intake to Heads
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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. |
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
19)
, 20)
, 21)
, 22)
photo by The Doctor71 of the XLFORUM http://xlforum.net/forums/showthread.php?t=2071371
23)
66xlch of the XLFORUM http://xlforum.net/forums/showthread.php?t=1079081&page=5
24)
photo by 66xlch of the XLFORUM http://xlforum.net/forums/showthread.php?t=1079081&page=5
25)
photo by DirtyCory of the XLFORUM http://xlforum.net/forums/showthread.php?t=1079081&page=7