REF: Carburetor, Intake Manifold & Exhaust


FACTORY CARBURETORS Installed on Sportsters 1957 - 2006


Carbs Used on Iron Head Sportsters from 1957-1985 by Serial / Model Number

Carburetor Serial#
or Carb Model#
Year Model Sportster
Linkert DC
(27155-57) was the first Sportster carburetor then replaced with (27155-57A) both introduced for 1957-1959 Sportsters 1)
DC-11957-1958 Sportster Early Style 2)
DC-1L1959-1960 Sportster 3)
DC-1M1959-1960 Military XLA Sportster 4)
DC-21959-65 Servicar (smaller venturi, opposite float bowl)5)
DC-61961 Sportster XLH and XLCH 6)
DC-71966 Big-Twin FL and FLH (larger venturi) 7)
DC-101962 and mid-63 Sportster XLH and XLCH 8)
DC-121966 Big-Twin FL and FLH mid-1963 1964 1965 Sportster XLH and XLCH 9)
Tillotson HD (1966-1971)
Mod HD-1A
Mod HD-1B
Pre 1966 XLCH
1966 and later XLCH
27162-66B10)
HD - 1BC
HD - 1C
Late '68 Sportsters (new check ball valve added to the accel pump passage)) 11)
27155-66RA (XLR) (27823-66R)
27155-70R (XR) (27823-66R)
Bendix / Zenith I6P12 (1972-Early 1976)
27155-72 12)1972-
27155-72A 13)1972-Early 1975
27155-72B14)1975-Early 1976
Mikuni (XR-750 Racing Engines Only)
VM-36-1
VM-36-4
VM36/39
1972-1980 XR-750 / 36 mm with a round slide 15)16)
TM38-85 (47mm spigot dia.)
TM38-86 (43mm spigot dia.)
TM38-85 (47mm spigot dia.)
TM38-86 (43mm spigot dia.)
1989-2003 XR-750 / 38 mm with a flat slide17)
Keihin butterfly (non-CV)(Late 1976-1987)
27153-76 18)Late 1976 XLH, XLCH
27153-77 19)1977-1978 XLH, XLCH
27469-78A
B83A 20)
1979 XL, XLCH, XLS
27469-80A
B83D 21)
1980 XL, XLS
27469-81A
B83F 22)
1981-Early 1982 XL, XLS
27469-82
B83G 23)
Late 1982 XL, XLS
27469-83C
B83K 24)
1983-1985 XL, XLS, XLX
27148-77
B75A 25)
1977-1978 XLCR 1000

Keihin Carbs Used on Evo Sportsters from 1986-2006 by Serial Number

  • All data compiled from HD Sportster Parts Catalogs unless otherwise noted
  • All CV models come equipped with accelerator pump unless noted.
  • The Serial Number on CV carbs is labeled on the adjacent side to the accelerator pump linkage
Keihin non-CV 1986 - 1987
Carburetor
Serial Number
Installed On
All Models
27501-86A (B83H(86-87) - XLH 883 All Models Domestic and California
27502-86B (B83H)(86-87) - XLH 1100 All Models Domestic and California
Keihin CV 1988 - 2006
Carburetor
Serial Number
Installed On
Domestic models
Year - Model
Installed On
California models
Year - Model
Installed On
Export models
Year - Model
27031-95 (95) - HDI 883 Deluxe
(95-97) - HDI 883, 883 Hug
(99-2000) - HDI 883, 883 Hug, 883C
(01) - Aust 883, 883 Hug, 883C
27031-95A (98) - HDI 883, 883 Hug
(02-03) - Aust 883, 883 Hug, 883C, 883R
27076-95 (95-97)- HDI 1200
(96-97) - HDI 1200C, 1200S
(99-01) - HDI 1200, 1200C
(01) - Aust, Eng, Japan 1200, 1200C
27076-95A (02-03) - HDI, Aust, Eng, Japan 1200, 1200C
27465-01 (01) - HDI, Eng, Japan 883, 883 Hug, 883C
27465-01A (02-03) - HDI, Eng, Japan 883, 883 Hug, 883C, 883R
27465-04 (04-06) - HDI 883, 883C
(05-06) - 883L, 883R
27076-95A (98) - HDI 1200, 1200C
27480-97(97) - 1200, 1200C, 1200S
(99-01) - 1200, 1200C
27480-97A(98) - 1200, 1200C
(02-03) - 1200, 1200C
27486-92 (92-Early 93) - 1200
27486-92A (93-94) - 1200
27486-92B (95) - 1200
27487-92(92-94) - 1200
27487-92A(95) - 1200
27488-92 (92-Early 93) - 883
27488-92A (Late 93-94) - 883
27488-92B (95) - 883
27489-92(92-94) - 883 All Models
27489-92A(95) 883 All Models
27490-96(96-97) - 883, 883 Hug
(99-01) - 883, 883 Hug, 883C
27490-96A(98) - 883, 883 Hug
(Late 98) - 883C
(02-03) - 883, 883 Hug, 883C, 883R
27490-04(04-06) - 883, 883C
(05-06) - 883L, 883R
27491-89
No Accel Pump
(89-90) - Swiss 1200
27491-96(96) - 1200, 1200C, 1200S
27492-89
No Accel Pump
89-90) - Swiss 883 All Models
27495-96 (96-97)- 883, 883 Hug
(99-01) - 883, 883 Hug, 883C
27495-96A (98) - 883, 883 Hug
(Late 98) - 883C
(02-03) - 883, 883 Hug, 883C, 883R
27495-04 (04-05) - 883, 883C
(05) - 883L, 883R
27498-96 (96-97) - 1200, 1200C, 1200S
(99-01) - 1200, 1200C
27498-96A (98) - 1200, 1200C
(02-03) - 1200, 1200C
27501-88
No Accel Pump
(88-90) - 883 All Models (89-90) - HDI 883 All Models
27501-89(89-90) - 883 All Models
(90) - 1200
27501-89A(91) - All Models
27502-88
No Accel Pump
(88-90) - 1200 (89-90) - HDI 1200
27502-89(89) - 1200
27503-88
No Accel Pump
(88) - 1200
27503-88A (89-90) - 1200
27503-88B (91) - All Models(91) - Swiss All Models
27503-92 (92) - HDI & Swiss All Models
27503-92A (93-94) - HDI & Swiss - All Models
27503-92B (95)- Swiss All Models
27504-88
No Acell Pump
(88) - 883 All Models
27504-88A (89-90) - 1200
27731-98(99-01) - 1200S
27731-98A)(98) - 1200S
(02-03) - 1200S
27731-04(04-06) - 1200C, 1200R
27732-98 (99-01) - 1200S
27732-98A (98) - 1200S \ (02-03) - 1200S
27732-04 (04-06) - 1200C, 1200R
27733-98 (98) - Swiss 1200S
27734-98 (98-2000) - HDI 1200S
27749-01 (01) - HDI, Aust, Eng, Japan 1200S
27749-01A (02-03) - HDI, Aust, Eng, Japan 1200S
27749-04 (04-06) - HDI 1200C,1200R

PERFORMANCE OPTIONS


Keihin BD (Screaming Eagle 40mm Kit)

  • Used in the Screaming Eagle Package line from HD as an Evolution XLH HI-FLO Carburetor & Air Cleaner.
  • Adjustable Accelerator Pump stroke
  • Incorporated a special intake manifold to carb spacer that had to be drilled and tapped (1/4 x 28) in the side for included Voes connection adapter
  • Required a 1987 replacement style intake manifold for 1988 and up models
  • Required possible grinding of the right rear corner of the front cylinder head, due to interference with the carburetor throttle pulley and cable guides, for proper clearance 26)
Carb #27001-88
Slow Jet Part No. Size (mm) Intermediate Air / Fuel Part No. Size Main Jet Size
27383-88 42 27113-87 Blank* 27106-85 1.30
27302-84 50 27109-87 55 27107-85 1.35
27329-83 52 27172-89 60* 27149-85 1.40
27284-85 55 27110-87 80 27151-85 1.45
27310-85 58 27111-87 1.00 27150-85 1.50
27318-85 60 27112-87 1.20 27108-87 1.60*
27283-85 62 27173-89 1.70 27119-88 1.65
27896-79 65 27134-89 1.70
27894-78 68*
27895-87 70
27897-78 72

27)

*in carburetor

Accelerator Pump

  • Accelerator pump rod length: A number of Screaming Eagle carb kits (91731-85A), packaged during March of 1988 (3/88 date code), contained carburetors with accelerator pump rods that were too short. The incorrect pump rods were only 2.35“ long, end to end, and completely disabled the accelerator pump and caused the engine to stumble upon fast acceleration. The correct length pump rod (27374-88) is 2.55”. 28)
  • Dealers were to check their parts stock and replace any pump rods that measured short and also check the pump rod length on any motorcycles that exhibited a stumble upon acceleration.

Breather Options

29)The horseshoe pipe system over the top of the carb allows for easy access to the mixture screw.30)

Aftermarket Carburetors


Mikuni Aftermarket Carbs and Upgrades

Sub Documents

HSR Series:

VM Series:

HS-40:

Solex:



Other than exact replacement OEM carburetors, all Mikuni aftermarket carburetors and tuning components are sold “As Is” for off road / racing use only. 31)
They are not intended or approved for use on vehicles operated on public roads or in locations where applicable engine tampering and anti-pollution laws apply.

There are plenty of Mikuni and Keihin carburetors in the market that are not authentic. 32)
They're not safe to use and will cause many problems to your bike.
If you're not sure if it's a genuine carburetor, the Sudco International site has a web page with pics of genuine and fake carbs.
Follow this link or you can call them directly to verify a seller. 33)

S&S Aftermarket Carbs and Upgrades

Sub Documents

S&S Super B Series

34) 35)

Throttle shaft leak repair.
Counter-bore each side a few thousandths less than the O-ring thickness so it sits a little proud. 36)
These are 1/4“ x 3/8” O-rings from a HF&T kit.
Then use a couple 1/4“ ID SS washers with a good synthetic grease like Super-Lube.
The return spring is on one side and you position the throttle lever on the other side.
So the washers just pinch the O-rings but still allow proper throttle movement. It should solve a shaft leak problem and can be easily maintained.
This was done on a milling machine with a mold ejection pin that fit perfectly.
To keep center, the pin was put in the spindle collet with an indicator as a confirmation of position after having moved the Z axis.
37) 38) 39)

S&S Super E Series

Accelerator Pump

There are 4 screws to take out to remove the float bowl.
Three obvious ones and the fourth one is one of the accelerator pump screws as in below.

Removing the accelerator pump.
The spring inside holds the diaphragm up until the rod pushes it down like a bellows.
40) 41)

S&S G, F and L Series

Sub Documents

1970s Era- Lake Injector

Sub Documents

* How to adjust the Lake Injector for all throttle positions


  • Originally made for airplanes, the Lake injector was a popular fuel delivery system in the 70s era. It was designed for the ultimate in performance with a minimum of tuning effort. Don't confuse the word “injector” with fuel injection, as these series of carburetors are not a fuel injector or a fuel injector body42). The body design, plus the velocity stack in unison with the throttle slide, forms a venture which enables the injector to achieve a good fuel/ air mixture. 43)
    • The manufacturer claimed a 15% - 25% or more increase in horsepower, unequalled acceleration, immediate starts and instant tuning.
    • Installation was a simple bolt on design with no modifications needed.
    • Suitable for 883s as well as 1000 model Sportsters although could be installed on Shovels, Pans, Triumphs and Hondas.
    • Body options for an extra price include, show chrome, bright anodized and 24K Gold.
  • A true low head, nil pressure injector as does not depend on venture suction like a carb but just pure air mass flow, so it self corrects for great altitude manifold pressure changes.44)
  • You wont fine tune this nail in a tube, they run rich when the tanks full, and get lean as the fuel drops.45)
  • Many people have to plumb air supply to the tank with a 'pop off' to keep pressure head constant below 1 PSI.46)
  • The unit is gravity feed instead of having a fuel pump for delivery and it was prone to leaking if you left the petcock open.47)
  • Posa and Star are all very similar and found their way from small aircraft and onto bikes.48)
  • POSA, Lake Injector, Revflow and Aero Carb are all float-less, diaphragm-less carburetors.
  • These carbs do not operate well on more than .5 lbs of fuel pressure yes that is less than half a pound of fuel pressure. These carbs do not vent any fuel vapor that may form in the body to the venturi as there is not float bowl well or diaphragm vent.49)

Bendix Stromberg Carburetor Identification

  • Bendix Stromberg used a unique identification scheme where a series of letters and numbers were assembled to identify and describe how a carburetor was constructed. The first two letters described the carburetor design, followed by a number that identified the size, and numbers and letters to identify specific design details and modifications.
  • The first (two) letter(s) comprise a Basic Design Code that places the Bendix Stromberg carburetor in a design category, where:
    • A – Pressure Injection Carburetors
    • E – Pressure Injection Carburetors
    • NA – Float-Type Carburetors
    • P – Pressure Injection Carburetors
    • Q – Pressure Injection Carburetors
    • R – Fuel Injection Systems
    • S – Speed Density Metering Systems
  • Example: NA-R9G
  • Prefix- “NA” – for float-type carburetors followed by a ”-“(dash)
  • The next letter indicates type, where
    • S – Single venturi updraft designed for two, three and four cylinder engines in the 25~95 hp class. NOT fitted with economizer, acceleration pump or mixture controls.
    • R – Single venturi updraft, designed for engines of all types in the 50-400 hp class. All are similar in design and incorporate needle valve type mixture control, accelerator pump and economizer. Some bodies are interchangeable in this series and deferent design economizers are used.
    • D – Double updraft venturi, with the float chamber to the rear, was considered obsolete c.1930
    • U – Double updraft venturi, with the float chamber between barrels. See specific models for details.
    • Y – Double vertical venturi (updraft), with two float chambers fore/aft of barrels. See specific models for details.
    • L – Inverted, down draft venturi.
    • T – Triple venturi, double float chamber fore/aft of barrels. The NA-T4 series is the only known model. Designed for use on Wright J-5 and other 9-cylinder radials, where each venturi feeds three cylinders. It has float similar to Y series, but with back suction mixture control. No economizer or accelerator pump.
    • F – Four-venturi with two separate float chambers. The last letter and numbers indicate a specific model.

Dellorto

Weber

The Weber is a very tunable carb for different motors with a nearly infinite set of jets, emulsion tubes, chokes, etc. 54)
The angled manifold that swings the carb towards the front of the bike, giving you leg room to tuck in behind the manifold / carb.

55)

56) 57)

58) 59) 60)


1)
1952-1959 HD Spare Parts Catalog pg 16
10) , 11)
Shop Dope Vol 4 Service Bulletin No 571 May 21, 1968
14)
HD Sportster Parts Catalog (99451-78B)
16) , 17)
1972-2003 HD XR-750 Service Manual pg 39
18) , 19)
HD Sportster Parts Catalog XLH/XLCH 99451-78B
20)
1979 Harley Davidson Sportster Parts Catalog
21)
1979-1985 HD XL Parts Catalog pg 23
22) , 23)
1979-1985 HD XL Parts Catalog pg 25
24)
1979-1985 HD XL Parts Catalog pg 27
25)
1977 HD XLCR Parts Catalog pg 57
28)
HD Service Bulletin #M-961 dated April 8, 1988
33)
Sudco International Corp. 2410 S. Sequoia Drive Compton, CA 90220 Tel.(310) 637-8330 • Fax (310) 637-8331
37) , 38) , 39)
photo by Tim The Grim of the XLFORUM http://xlforum.net/forums/showthread.php?t=2074290
50) , 51) , 52) , 53)
photo by Yellowstone Kelley of the XLFORUM
56) , 57)
photo by ericfreeman of the XLFORUM http://xlforum.net/forums/showthread.php?t=1206675
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