Differences

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--- techtalk:evo:carb01 [2020/05/17 20:41]
ixl2relax
+++ techtalk:evo:carb01 [2023/11/17 13:29]
hippysmack [Keihin Butterfly (non-CV) Carburetor (Stock on L1976-1987 Sportsters)]
@@ Line 2: / Line 2: @@
 ====== EVO: Carburetor, Intake Manifold & Exhaust ======
-====== Overview ======
+====== Overview - Basic Stock Carb Model Info ======
 From 1986-1987, the stock Sportster carburetor was a Keihin 34mm, fixed-venturi "butterfly" model, as used on the Ironhead models from 1979 onward (BT models still used the 38mm version). Contrary to popular folklore, all Keihin non-CV carbs did come with accelerator pumps.
@@ Line 14: / Line 14: @@
 ====== Keihin Butterfly (non-CV) Carburetor (Stock on L1976-1987 Sportsters) ======
+See also in the Sportsterpedia: \\
+  * [[techtalk:ih:carb01#keihin_butterfly_or_non-cv_carb_late_1976-1987|Keihin Butterfly Carb Basic Information]]
+  * [[techtalk:ih:carb01q|Rebuilding the Keihin Butterfly Carb]]
+  * [[techtalk:ih:carb01p|Keihin Butterfly Carb Identificaton]]
+  * [[techtalk:miscres:miscres05#tsb_650-699|See TSB #694 for introduction information on the Keihin butterfly carb]]. \\ Click the link to view the TSB page in the Sportsterpedia. Then click on the "Y" next to #694 to view / download the PDF. \\
   * The Keihin non-CV carburetor is a horizontal type with a fuel bowl, single ring-shaped float, an accelerating pump, idle mixture adjusting needle and a throttle stop screw for speed adjustment. ((1970-1978 HD XL/XLH/XLCH/XLT 1000 FSM))
   * The throttle body casting contains an integral venturi and a fuel valve seat that is pressed into the body. The underside of the throttle body contains a boss. The main jet screws into the boss and holds the bleed tube in place.((1970-1978 HD XL/XLH/XLCH/XLT 1000 FSM))
@@ Line 85: / Line 91: @@
 //
   * Used in the Screaming Eagle Package line from HD as an Evolution XLH HI-FLO Carburetor & Air Cleaner. The carb was a (27001-88)
-  * The kit Number is 29081-90C for 86 and later Sportsters.
+  * The kit Number is 29081-90C for 86 and later Sportsters. Carb stamping is (27FA) plus a 4 character date code.
   * 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  ((http://xlforum.net/forums/showthread.php?t=132922))
+  * Build kits and the bowl gasket are obsolete and hard to find.
+    * The bowl gasket (27013-85) has been found at JW Boon.com but not the build kit. \\ [[https://jwboon.com/index2.php?content=https%3A//jwboon.com/dbhtml/catalog/Bool_OR/Fits_FLT%2520%2522Tour%2520Glide%2522/Section_inlet|Click here for a Link to their add]]. However, they do not ship to the U.S.
+    * Dennis Kirk sells a kit that looks to have the correct bowl O-ring included under Parts Unlimited branding.  Kit (1003-1671). \\ [[https://www.denniskirk.com/parts-unlimited/carb-rebuild-kit-1003-1671.p175288.prd/175288.sku|Click here for the link]]. However, according to the Q&A at the bottom of the page, the O-ring doesn't fit the SE carb. That needs to be verified.
+    * Parts Unlimited shows kit# 175288 (1003-1671) as a replacement for the stock paper gasket on Yamahas, still a Keihin though and the gasket (O-ring) looks the same. \\ [[https://www.parts-unlimited.com/prod...umber=10031671|Click for the link]]
+    * Speed Supplies.com has a listing for the bowl O-ring (27013-85) although there is no pic of it. ((LenC of the XLFORUM http://xlforum.net/forums/showthread.php?t=2076892&page=3)) \\ [[http://www.speedsupplies.com/partslisting.asp?position=312&increment=500&category=HD|Click here for the link]]
-^  PART NUMBERS & JET SIZES (IN MM) FOR KEIHIN BD CARBURETORS  ^^^^^^^^
+^  JET PART NUMBERS & SIZES (IN MM) FOR KEIHIN BD CARBURETORS  ^^^^^^^^
 ^Slow Jet  ^Size | ^Int. Air/Fuel Jet ^Size  | ^Main Jet ^Size  |
 |27383-88 |42 | |27113-87 |Blank* | |27106-85 |1.30 |
@@ Line 106: / Line 118: @@
 |              * in carburetor               ||||||||
  ((http://xlforum.net/forums/showthread.php?t=132922))
+\\
+^  XLH Hi-Flo Carburetor and Air Cleaner Kit (29081-90C) Parts List  ||||||
+|Item Description|Part No.|Item Description|Part No.|Item Description|Part No.|
+|VOES fitting|29190-85|Backplate|29075-91|Crankcase breather hose fitting|29034-85|
+|Gasket|27022-88|Button head screw|927A|O-ring|11110|
+|Manifold spacer|29275-88|Support spacer, \\ small I.D.|6786|Hose clamp|9946|
+|Carburetor assembly|27001-88|Support spacer, \\ large I.D.|6785|Venturi|29148-90|
+|Allen head bolts|3485A|Hex head bolt|3427|Air cleaner element|29025-88B|
+|Washer|6702|Allen head bolt|3587A|Vacuum hose kit|26553-94|
+|Lockwasher|7041|Washer|6333|Air cleaner trim|29024-88|
+|Air cleaner adapter|27041-90|Washer|6738|Bowl O-ring|27013-85|
+|Allen head bolt|885A|Gasket|27077-78|Rebuild Kit|91731-85A \\ See [[techtalk:miscres:miscres05#tsb_950-999|TSB M-961]]|
+|Nut|7686|Lockwasher|7068|
+|Washer|6228W|Air cleaner cover spacer|31523-88|
+|Carburetor gasket|27044-90|Counter-sunk allen head screw|3795|
 {{:techtalk:evo:carb:se_carb_functions.jpg?direct&300|}}
@@ Line 138: / Line 168: @@
 == Operation: ==
-  *  The carburetor atomizes gas in proper proportions to the air  pulled in through the air intake. At idle, a small amount of gas is siphoned through the pilot jet by the incoming air. The more the throttle is opened, the air begins siphoning through the main and needle jets. The tapered needle increases the flow of the needle jet as it is lifted since it's taper gets smaller as it sets inside the needle jet thus allowing for more flow when lifted up and out. Vacuum from carbs intake,the engine side of the throttle plate, is used to lift the slide barrel/ needle jet. At full throttle, the carburetor venturi is fully opened and the needle is lifted far enough to allow the main jet to flow at full jet capacity. The choke circuit is actually the starting enrichment valve system. The choke knob opens an enrichment valve. With the choke knob in the open position, the slow jet sends a stream of gas into the carburetor's venture thus enriching the gas/air mixture when the engine is cold. The accelerator pump circuit injects a fine spray of gas into the carburetor intake during sudden acceleration to reduce engine hesitation.
+  *  The carburetor atomizes gas in proper proportions to the air pulled in through the air intake. The throttle plate controls the amount of air flow. At idle, a small amount of gas is siphoned through the pilot jet by the incoming air and fed thru the Idle Port on the engine side of the throttle plate. As the throttle plate is opened farther, the air begins siphoning gas through the transfer ports (which are fed by the Pilot Jet) and eventually pulls gas thru the needle jet (which is fed by the main jet). The tapered needle, which moves up and down thru the fixed diameter needle jet, increases the flow of fuel as it is lifted up since it's taper gets smaller inside the needle jet, thus allowing for more flow when lifted up and out. The vacuum, in the air filter side of the throttle plate, is used to lift the slide barrel & needle jet. At full throttle, the carburetor venturi is fully opened and the needle is lifted far enough to allow the main jet to flow at full jet capacity. The choke circuit is actually an enrichment valve system to allow more fuel at startup. With the choke knob pulled out, a separate jet opening sends a stream of gas into the carburetor's venturi, on the engine side of the throttle plate, thus enriching the gas/air mixture when the engine is cold. The accelerator pump circuit injects a fine spray of gas into the carburetor intake during sudden twisting of the throttle to aid acceleration & reduce engine hesitation.
 ----
@@ Line 438: / Line 468: @@
 |HDI/Aust/Eng/Japan|2001|27749-01|185 / 42|(27185-90) - (27171-89)|(27647-01)|
 |HDI/Aust/Eng/Japan|2002-2003|27749-01A|185 / 42|(27185-90) - (27171-89)|(27647-01)|
+\\
+===== Slow & Main Jets - P/N & Comparisons =====
+^  Chart of Slow (Pilot) Jet Size Differences  |||||||
+| Number | HD Part # | MM | Dia Inches | Area Inch² | %+ of\\ Prev Jet | %± of\\ 42 Jet |
+^ |||||||
+| Keihin 35 | 27117-88 | 0.35 | 0.013780 | 0.0001491 | ~~ | -30.56 |
+| Keihin 40 | 27281-92 | 0.40 | 0.015748 | 0.0001947 | 30.61 | -9.30 |
+| Keihin 42 | 27171-89 | 0.42 | 0.016535 | 0.0002146 | 10.25 | --TYP-- |
+| Keihin 45 | 27170-89 | 0.45 | 0.017717 | 0.0002464 | 14.80 | 14.80 |
+| Keihin 48 | 27165-90 | 0.48 | 0.018898 | 0.0002803 | 13.78 | 30.61 |
+| |||||||
+| Keihin 44 | CV-Perf | 0.44 | 0.017323 | 0.0002356 |  | 9.75 |
+| Keihin 46 | CV-Perf | 0.46 | 0.018110 | 0.0002575 |  | 19.95 |
+| Keihin 50 | CV-Perf | 0.50 | 0.019685 | 0.0003042 |  | 41.72 |
+| |||||||
+| CV-Perf is for CV-Performance.com |||||||
+| Keihin P/N for above listed jets is N424-25B-XX <-- where XX is the size |||||||
+| The N424-25B-XX series jets have 0.8mm bleed (cross) holes |||||||
+| |||||||
+^  Chart of Main Jet Size Differences  |||||||
+| Number | HD Part # | MM | Dia Inches | Area Inch² | %+ of\\ Prev Jet | %± of\\ 170 Jet |
+^ |||||||
+| Keihin 160 | 27152-89 | 1.60 | 0.062992 | 0.0031149 | ~~ | -11.42 |
+| Keihin 165 | 27116-88 | 1.65 | 0.064961 | 0.0033126 | 6.35 | -5.80 |
+| Keihin 170 | 27115-88 | 1.70 | 0.066929 | 0.0035164 | 6.15 | --TYP-- |
+| Keihin 175 | 27090-89 | 1.75 | 0.068898 | 0.0037263 | 5.97 | 5.97 |
+| Keihin 180 | 27114-88 | 1.80 | 0.070866 | 0.0039423 | 5.80 | 12.11 |
+| Keihin 185 | 27185-90 | 1.85 | 0.072835 | 0.0041643 | 5.63 | 18.43 |
+| Keihin 190 | 27243-95 | 1.90 | 0.074803 | 0.0043925 | 5.48 | 24.91 |
+| Keihin 195 | 	27275-96Y | 1.95 | 0.076772 | 0.0046267 | 5.33 | 31.57 |
+| Keihin 200 | 27105-88 | 2.00 | 0.078740 | 0.0048670 | 5.19 | 38.41 |
+| |||||||
+| Keihin P/N for above listed jets is N424-27-XXX <-- where XXX is the size |||||||
+| Area Inch² = 3.14 * DiaInches/2 * DiaInches/2 = π*r² |||||||
 \\

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