Differences

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--- techtalk:ref:carb01w [2025/02/11 15:01] – [General] hippysmack
+++ techtalk:ref:carb01w [2025/03/18 13:52] (current) – [Basic Keihin BD (Screaming Eagle or Flowmaster) Butterfly Carb Information] hippysmack
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 <wrap em>It's shown everywhere on the drag racing circuit that racers are winning with Screamin Eagle carburetors. ((HD Dealer News, August 1989))  </wrap>
+|
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 ====== Carburetors ======
 ===== General =====
-**Snowmobile applications**: As a side note, a version of these (Keihin butterfly) type carbs was also used on 1980s Yamaha snowmobiles (1980 Yamaha SS440 had a 34mm flowmaster type butterfly spigot mount carb). The SS440 carbs were Keihin BD38-34 from 1980-1982 and Keihin BD38-44 from 1983-1985 ((Stratoman of Snowmobole.com https://www.snowmobileforum.com/threads/keihin-carb-parts-and-info.50158/))  along with several other model sleds. The snowmobile carbs are basically the same type carb with some parts moved around or changed from the flowmaster motorcycle version. The bowl on some was moved off center, most did not have an accelerator pump and the butterfly plates have a hole drilled thru them. So for practical purposes, a snowmobile carb is not a motorcycle carb. One could also say these resemble Mikuni butterfly carbs as well. \\
-**Motorcycle applications**: These type carbs are made by Keihin and were sold under either Andrews or Harley Davidson. The first was Andrews (famous maker of cams today). The flange mount carb was called a Flow Master and it beared the names cast into the side of the mounting flange of Andrews on one side and Flow Master on the other side. The Andrews Flowmaster carbs (per Andrews) were basically all the same carbs but the fuel inlet fitting for Sportsters is pointing straight up for easier fuel line routing. Andrews carbs supplied after 9/1986 have brass fuel fittings. In 1985 (first available for parts order on 4-1-1985), HD started selling the Flowmaster type motorcycle carb under the Screamin Eagle brand. ((P&A bulletin #244))  The first couple HD versions were spigot mount carbs and then later the 2 bolt flange was added back. All of them bear the name cast into the body on the front side above the float bowl as Keihin Japan. The flanged model Screamin Eagle carbs have Harley Davidson cast into one side of the mounting flange and Screamin Eagle cast into the other side. The spigot mount carbs do not have name branding other than Keihin Japan cast into the front side above the float bowl.
+**Snowmobile applications**: As a side note, a version of these (Keihin butterfly) type spigot mount carbs was also used on 1980s Yamaha snowmobiles (1980 Yamaha SS440 had a 34mm flowmaster type butterfly spigot mount carb). The SS440 carbs were Keihin BD38-34 from 1980-1982 and Keihin BD38-44 from 1983-1985 ((Stratoman of Snowmobole.com https://www.snowmobileforum.com/threads/keihin-carb-parts-and-info.50158/))  along with several other model sleds. The snowmobile carbs are basically the same type carb with some parts moved around or changed from the flowmaster motorcycle version. The bowl on some was moved off center, most did not have an accelerator pump and the butterfly plates have a hole drilled thru them (motorcycle versions do not have the plate drilled). And most have dual bowl vent lines (left and right sides) where the motorcycle versions only have the right side bowl vent. So for practical purposes, a snowmobile carb is not a motorcycle carb although the body (base mold) is the same. One could also say these resemble Mikuni butterfly carbs of the era as well. HD (under AMF) made snowmobiles from 1971-1975 but used Tillotson HD carbs on them.
+**Motorcycle applications**: These type carbs are made by Keihin and were sold under either Andrews or Harley Davidson. The first was Andrews (famous maker of cams today). The flange mount carb was called a Flow Master and it beared the names cast into the side of the mounting flange of Andrews on one side and Flow Master on the other side. The Andrews Flowmaster carbs (per Andrews) were basically all the same carbs but the fuel inlet fitting for Sportsters is pointing straight up for easier fuel line routing. Andrews carbs supplied after 9/1986 have brass fuel fittings. In 1985 (first available for parts order on 4-1-1985), HD started selling the Flowmaster type motorcycle carb under the Screamin Eagle brand. ((P&A bulletin #244))  The first couple HD versions were spigot mount carbs and then later the 2 bolt flange was added back. All of them bear the name cast into the body on the front side above the float bowl as Keihin Japan. The flanged model Screamin Eagle carbs have Harley Davidson cast into one side of the mounting flange and Screamin Eagle cast into the other side. The spigot mount carbs do not have name branding other than Keihin Japan cast into the front side above the float bowl.
-**1989 Improvements**: ((1989 Enthusiast Magazine Summer Edition pgs 16-17)) \\
+**1989 Improvements**: ((Enthusiast Magazine Summer Edition pgs 16-17))  \\
-This is an exerpt from an article in the 1989 summer edition Enthusiast magazine. Dick "Doctor Speed" Parisey (HD Project Engineer) devoted an exhaustive testing program to the completely redesigned and improved fuel deliver system in the new flange mounted SE butterfly carb including both bench and dyno tests. As a result, he believed the new 40mm unit outflowed other similar carbs on the market. For example, with the Screamin Eagle air cleaner installed, the new unit flowed 180.6 cubic feet per minute (CFM) compared to 158.0 CFM measured on a well known aftermarket manufacturer's similar setup. In fact, at 10" of water (a basis for flow testing), the bare SE carb flowed 185 CFM while another aftermarket manufacturer's comparable setup flowed 183 CFM. This is a 10% improvement over the standard 1340 carb which flows 168 CFM. It's equal to or better than any carb that we tested in terms of overall high volume flow characteristics. But this new carb really has a tremendous advantage over others by providing the professional rider or tuner with the ability to fine tune it's midrange. See the whole article in the documents section above. \\
+This is an exerpt from an article in the 1989 summer edition Enthusiast magazine. Dick "Doctor Speed" Parisey (HD Project Engineer) devoted an exhaustive testing program to the completely redesigned and improved fuel deliver system in the new flange mounted SE butterfly carb including both bench and dyno tests. As a result, he believed the new 40mm unit outflowed other similar carbs on the market. For example, with the Screamin Eagle air cleaner installed, the new unit flowed 180.6 cubic feet per minute (CFM) compared to 158.0 CFM measured on a well known aftermarket manufacturer's similar setup. In fact, at 10" of water (a basis for flow testing), the bare SE carb flowed 185 CFM while another aftermarket manufacturer's comparable setup flowed 183 CFM. This is a 10% improvement over the standard 1340 carb which flows 168 CFM. It's equal to or better than any carb that we tested in terms of overall high volume flow characteristics. But this new carb really has a tremendous advantage over others by providing the professional rider or tuner with the ability to fine tune it's midrange. See the whole article in the documents section above.
 The carb that came in kit (91731-88) was 40mm flange mount version and advertised to have an improved fuel delivery system including a redesigned slow speed transfer port network, new main and slow jets, new "intermediate" jet amd new intermediate fuel port (plastic/brass fuel inlet changed to a different plastic/brass fuel inlet). One piece die cast aluminum carb body, with integral mounting flange, bolts directly to the manifold eliminating the need for a rubber adapter for easier installation. The addition of the intermediate fuel circuit (adjustable by changing jets) eliminates a potential lean condition (or surging) at 2500-3500 cruise RPM with a partial throttle.\\
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 Typical spigot mount carb. \\ {{:techtalk:evo:carb:se_high_flow_carb_1_by_88hugger.jpg?direct&400|se_high_flow_carb_1_by_88hugger.jpg}}((photo by 88hugger of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-intake-and-exhaust/sportster-motorcycle-air-intake-carburetor-efi-fuel-and-exhaust/72194-carb-questions#post1906502)) {{:techtalk:evo:carb:se_high_flow_carb_2_by_88hugger.jpg?direct&400|se_high_flow_carb_2_by_88hugger.jpg}}((photo by 88hugger of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-intake-and-exhaust/sportster-motorcycle-air-intake-carburetor-efi-fuel-and-exhaust/72194-carb-questions#post1906502))
-Typical flange mount carb. \\ {{:techtalk:ref:carb:keihin_bd_27fa_eb22_se_carb_by_cyclewarehouse_pic1.jpg?direct&400|}} ((photo courtesy of Ebay seller, cyclewarehouse. [[https://www.ebay.com/sch/cyclewarehouse/m.html?_nkw=&_armrs=1&_ipg=&_from=|Link to Items for Sale]] )) {{:techtalk:ref:carb:keihin_bd_27fa_eb22_se_carb_by_cyclewarehouse_pic2.jpg?direct&400|}} ((photo courtesy of Ebay seller, cyclewarehouse. [[https://www.ebay.com/sch/cyclewarehouse/m.html?_nkw=&_armrs=1&_ipg=&_from=|Link to Items for Sale]] ))
+Typical flange mount carb. \\ {{:techtalk:ref:carb:keihin_bd_27fa_eb22_se_carb_by_cyclewarehouse_pic1.jpg?direct&400|keihin_bd_27fa_eb22_se_carb_by_cyclewarehouse_pic1.jpg}}((photo courtesy of Ebay seller, cyclewarehouse. [[https://www.ebay.com/sch/cyclewarehouse/m.html?_nkw=&_armrs=1&_ipg=&_from=|Link to Items for Sale]])) {{:techtalk:ref:carb:keihin_bd_27fa_eb22_se_carb_by_cyclewarehouse_pic2.jpg?direct&400|keihin_bd_27fa_eb22_se_carb_by_cyclewarehouse_pic2.jpg}}((photo courtesy of Ebay seller, cyclewarehouse. [[https://www.ebay.com/sch/cyclewarehouse/m.html?_nkw=&_armrs=1&_ipg=&_from=|Link to Items for Sale]]))
 ===== Identifying Numbers =====
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 ===== Individual Air Cleaner Parts and Pics =====
 ^{{:techtalk:miscres:instruction_sheet_header_4.png?nolink&803}}^^|
 |  Hunting down parts for use on Sportsters  |||
@@ Line 352: / Line 357: @@
 |{{:techtalk:ref:carb:1972-1985_sportster_carb_support_bracket_29053-85_by_d_s_cycle_connection.jpg?direct&400|1972-1985_sportster_carb_support_bracket_29053-85_by_d_s_cycle_connection.jpg}}|{{:techtalk:ref:carb:1976-1985_xl_air_cleaner_support_bracket_adapter_kit_29297-85_by_robison_motorcycles.jpg?direct&400|1976-1985_xl_air_cleaner_support_bracket_adapter_kit_29297-85_by_robison_motorcycles.jpg}}|
-Using an aluminum oval backplate from the kits, 2 "Z" brackets (29122-85) were used on Ironheads. Brackets attach to the heads and then to 2 holes in the backing plate. \\
+Using an aluminum oval backplate from the kits, 2 "Z" brackets (29122-85) were used on Ironheads. Brackets attach to the heads and then to 2 holes in the backing plate.
-|1974-1985 Sportster A/C Mounting Bracket Adapter Kit 29122-85 ((photo courtesy of Ebay seller, Robison Motorcycles [[ https://www.ebay.com/str/robisonmotorcycles?_trksid=p2047675.l2563 |Link to Ebay Store]]))|
+|1974-1985 Sportster A/C Mounting Bracket Adapter Kit 29122-85 ((photo courtesy of Ebay seller, Robison Motorcycles [[ https://www.ebay.com/str/robisonmotorcycles?_trksid=p2047675.l2563 |Link to Ebay Store]]))    |
 |{{:techtalk:ref:carb:1974-1985_sportster_air_cleaner_mounting_bracket_adapter_kit_29122-85_by_robisonmotorcycles.jpg?direct&400|1974-1985_sportster_air_cleaner_mounting_bracket_adapter_kit_29122-85_by_robisonmotorcycles.jpg}}|
-|1986-1990 Sportster Air Cleaner Support Bracket (29258-86) ((photo courtesy of Ebay seller, animalhouse2010, [[https://www.ebay.com/str/animalhouse2010?_trksid=p2047675.l2563|Link to Ebay store:]] ))|1986-1990 Sportster Air Cleaner Support Bracket (29193-86) ((photo courtesy of Ebay seller, animalhouse2010, [[https://www.ebay.com/str/animalhouse2010?_trksid=p2047675.l2563|Link to Ebay store:]]))    |
+|1986-1990 Sportster Air Cleaner Support Bracket (29258-86) ((photo courtesy of Ebay seller, animalhouse2010, [[https://www.ebay.com/str/animalhouse2010?_trksid=p2047675.l2563|Link to Ebay store:]]))    |1986-1990 Sportster Air Cleaner Support Bracket (29193-86) ((photo courtesy of Ebay seller, animalhouse2010, [[https://www.ebay.com/str/animalhouse2010?_trksid=p2047675.l2563|Link to Ebay store:]]))    |
 |{{:techtalk:ref:carb:1986-1990_xl_carb_adapter_kit_29258-86_by_animalhouse2010_pic1.jpg?direct&400|1986-1990_xl_carb_adapter_kit_29258-86_by_animalhouse2010_pic1.jpg}}|{{:techtalk:ref:carb:1986-1990_sportster_air_cleaner_support_bracket_29193-86_by_animalhouse2010.jpg?direct&400|1986-1990_sportster_air_cleaner_support_bracket_29193-86_by_animalhouse2010.jpg}}|
+\\
 |Injection molded air cleaner adapter (27041-90) used on XLs & BTs. \\ Fits on the mouth of the carb to attach the backing plate.  |Air Cleaner Gasket 27044-90 ((photo courtesy of Ebay seller, 57harleyrider. [[https://www.ebay.com/str/57harleyrider|Link to Ebay Store]]))    |
 |{{:techtalk:ref:carb:air_cleaner_adapter_27041-90_by_robisonmotorcycles.jpg?direct&400|air_cleaner_adapter_27041-90_by_robisonmotorcycles.jpg}}|{{:techtalk:ref:carb:air_cleaner_gasket_27044-90_by_57harleyrider.jpg?direct&400|air_cleaner_gasket_27044-90_by_57harleyrider.jpg}}|
+\\
-|Tapered plastic carb spacer adapter (29275-88) ((photo courtesy of Ebay seller, animalhouse2010, [[https://www.ebay.com/str/animalhouse2010?_trksid=p2047675.l2563|Link to Ebay store:]] ))|Nylon Hose Fitting (29190-85) for VOES on plastic spacer ((photo courtesy of Ebay seller, Robison Motorcycles [[ https://www.ebay.com/str/robisonmotorcycles?_trksid=p2047675.l2563 |Link to Ebay Store]]))    |
+|Tapered plastic carb spacer adapter (29275-88) ((photo courtesy of Ebay seller, animalhouse2010, [[https://www.ebay.com/str/animalhouse2010?_trksid=p2047675.l2563|Link to Ebay store:]]))    |Nylon Hose Fitting (29190-85) for VOES on plastic spacer ((photo courtesy of Ebay seller, Robison Motorcycles [[ https://www.ebay.com/str/robisonmotorcycles?_trksid=p2047675.l2563 |Link to Ebay Store]]))    |
 |{{:techtalk:ref:carb:tapered_carburetor_adapter_29275-88_by_animalhouse2010.jpg?direct&400|tapered_carburetor_adapter_29275-88_by_animalhouse2010.jpg}}|{{:techtalk:ref:carb:nylon_hose_fitting_for_voes_29190-85_by_robisonmotorcycles.jpg?direct&400|nylon_hose_fitting_for_voes_29190-85_by_robisonmotorcycles.jpg}}|
+\\
-|Air Cleaner Venturi 29148-90 ((photo courtesy of Ebay seller, 57harleyrider. [[https://www.ebay.com/str/57harleyrider|Link to Ebay Store]]))|
+HD calls this a "venturi" but that is a misnomer. Harley terminolgy is often confusing. 1984-1988 high flow air cleaners in these kits did not have a "venturi" since the K&N air filter was tapered to allow air flow to gather at the carb's mouth. The exception would have been the original 1984 fiter that was not tapered. 1989-up air cleaners use the "venturi" against the air cleaner side of the backing plate and the backing plate was redesigned to use an oval type non tapered K&N filter. The 1992 Genuine catalog and 1995 SE catalog calls it a radioused venturi that increases air flow and minimizes turbulence. The 1999 SE catalog calls this a radioused inlet ring. But throughout all, HD claims these systems have been bench tested and dyno'd and they never gave up on the idea of the "venturi or radioused inlet ring". In fact, later backing plates for hi flow CV carbs included a backing plate with a built in "venturi".
+|Air Cleaner Venturi 29148-90 ((photo courtesy of Ebay seller, 57harleyrider. [[https://www.ebay.com/str/57harleyrider|Link to Ebay Store]]))    |
 |{{:techtalk:ref:carb:air_cleaner_venturi_29148-90_by_57harleyrider.jpg?direct&400|air_cleaner_venturi_29148-90_by_57harleyrider.jpg}}|
+\\
-**Intake manifold**s: \\
+**Intake manifold**s:\\
-The stock 1986-1987 Sportster intake manifold is suggested if using the SE butterfly carb on 1988-later XLs. It is flanged to accept the flanged SE carb using a tapered plastic spacer and flange gaskets. An after market manifold, Ram Jett, was available also (now obsolete). The Ram Jett manifolds for Sportsters have an "S" stamped into a boss on the top center. The boss can be drilled and tapped for the VOES fitting (however doing so got rid of the designation letters). \\
+The stock 1986-1987 Sportster intake manifold is suggested by HD if using the SE butterfly carb on 1988-later XLs. It is flanged at each head connection and also at the carb mount to accept the flanged SE carb using a tapered plastic spacer and flange gaskets or the Mikuni flange to spigot adapter. An after market manifold, Ram Jett, was available also (now obsolete). \\
-|1986-1987 Sportster OEM intake manifold (27004-86) (( photos courtesy of Stripped Down Cycles [[https://www.ebay.com/str/strippeddowncycles?_trksid=p2047675.m3561.l2563|Link to Ebay Store:]]))|
+The Ram Jett , CAS part#(DS289215) manifolds are also flanged on all three sides and have an "S" stamped into a boss on the top center for use on Sportsters. The boss can be drilled and tapped for the VOES fitting (however doing so got rid of the designation letters). The "S" versions are considerably narrower than big twin intakes. One-piece, heat-treated aluminum manifolds accommodate expansion, contraction and cylinder vibration. For stock XL 883, 1100, 1200 XL Evolution, flange-type mount (must use 36-38mm spigot adapter flange (MVM36-200), 5/8" shorter to compensate for spigot adapter when using OEM CV carb on 88-00 models; carb opening in manifold 1-5/8" (40mm) which matches the 40mm SE butterfly carbs. ((http://cas4.com/Carburetors-Intakes/carbs-intakes-manifolds-kits-seals-hardware.html)) These intakes came with 12 point mounting bolts instead of the stock allen head bolts. Used Ram Jetts usually lack the bolts but you can take Allen head bolts and reduce their OD slightly (chuck in drill then hold against a grinder, or use a lathe) to clear the casting. ((Farmall from Harley Tech Forum https://harleytechtalk.com/htt/index.php?topic=108599.0)) James Gaskets sells a gasket kit (JGI-27002-89-R) with the 2 head flange paper gaskets but it has a spigot mount rubber for the carb mount. Or, the gaskets are easy to cut from Fel-Pro gray paper (from any auto store). ((farmall of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/frame-mount-evo-sportster-talk-1986-2003-models/201038-1991-manifold-bolt-trivia)) \\
+|1986-1987 Sportster OEM intake manifold (27004-86) (( photos courtesy of Stripped Down Cycles [[https://www.ebay.com/str/strippeddowncycles?_trksid=p2047675.m3561.l2563|Link to Ebay Store:]]))    |
 |{{:techtalk:evo:carb:1986-1987_sportster_intake_manifold_pic2_by_stripped_down_cycles.jpg?direct&400|1986-1987_sportster_intake_manifold_pic2_by_stripped_down_cycles.jpg}}|
+\\
-|  Oval air cleaner backing plate (29069-90) used in A/C kits 29081-90 and 29082-90 without head breather holes (( photos courtesy of Ebay seller, 1960downunder, Link to Ebay Store https://www.ebay.com/str/1960downunder))  ||
+|  Oval air cleaner backing plate (29069-90) used in A/C kits 29081-90 and 29082-90 without head breather holes (( photos courtesy of Ebay seller, 1960downunder, Link to Ebay Store https://www.ebay.com/str/1960downunder)) </sup>    ||
 |{{:techtalk:ref:carb:oval_air_cleaner_backing_plate_29069-90_by_1960downunder_pic1.jpg?direct&400|oval_air_cleaner_backing_plate_29069-90_by_1960downunder_pic1.jpg}}|{{:techtalk:ref:carb:oval_air_cleaner_backing_plate_29069-90_by_1960downunder_pic2.jpg?direct&400|oval_air_cleaner_backing_plate_29069-90_by_1960downunder_pic2.jpg}}|
-|  Oval air cleaner backing plate (29075-91) used in A/C kit 29081-90C with head breather holes (( photos courtesy of Ebay seller trebla119, Link to Ebay Store https://www.ebay.com/str/trebla119))  ||
+|  Oval air cleaner backing plate (29075-91) used in A/C kit 29081-90C with head breather holes (( photos courtesy of Ebay seller trebla119, Link to Ebay Store https://www.ebay.com/str/trebla119)) </sup>    ||
 |{{:techtalk:ref:carb:oval_air_cleaner_backing_plate_29075-91_by_trebla119_pic1.jpg?direct&400|oval_air_cleaner_backing_plate_29075-91_by_trebla119_pic1.jpg}}|{{:techtalk:ref:carb:oval_air_cleaner_backing_plate_29075-91_by_trebla119_pic2.jpg?direct&400|oval_air_cleaner_backing_plate_29075-91_by_trebla119_pic2.jpg}}|
-|  SE Clamp-on Air Filter and 7" Cover (does not use the carb adapter) (( photos by t0mmy91 of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-general-discussion-and-problems/4956055-basketcase-1990-sportster-1200-screaming-eagle-air-breather-help#post4957209))  ||
+|  SE Clamp-on Air Filter and 7" Cover (does not use the carb adapter) (( photos by t0mmy91 of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-general-discussion-and-problems/4956055-basketcase-1990-sportster-1200-screaming-eagle-air-breather-help#post4957209)) </sup>    ||
 |{{:techtalk:ref:carb:se_clamp-on_air_filter_and_cover_pic1_by_t0mmy91.jpg?direct&400|se_clamp-on_air_filter_and_cover_pic1_by_t0mmy91.jpg}}|{{:techtalk:ref:carb:se_clamp-on_air_filter_and_cover_pic2_by_t0mmy91.jpg?direct&400|se_clamp-on_air_filter_and_cover_pic2_by_t0mmy91.jpg}}|
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