• Used in the Screaming Eagle Package line from HD as an Evolution XLH HI-FLO Carburetor & Air Cleaner.
• It came in flange mount and spigot mount styles. ¹⁾
  • The first ones were called Andrews Flowmasters.
    They used a rubber adapter flange and a hose clamp to hold the carb on to the manifold and a K&N air cleaner held on by a hose clamp.
  • Later issues of this carb (called Screaming Eagle) were cast with a flange to allow the carb to bolt to the manifold. ²⁾
    The spigot mount looks a lot like the original Lectron mount from H-D. ³⁾
• Adjustable Accelerator Pump stroke
• Markings include:
  • Keihin, 27F8, HG13, Harley Davidson and Screaming Eagle. ⁴⁾
  • Screaming Eagle (27FA ED17) ⁵⁾

Marketing information on the Screaming Eagle High Flow Carb and Air Cleaner Kit (91731-88):
Harleys equipped with high performance engine parts may not be used on public roads and in some cases must be restricted to closed course competition.
Engine related performance parts are intended for the experienced rider only.

One piece die cast aluminum carb body, with integral mounting flange, bolts directly to the manifold eliminating the need for a rubber adapter.
The addition of the intermediate fuel circuit (adjustable by changing jets) eliminates a potential lean condition (or surging) at 2500-3500 cruise RPM.
Features:

• Large radius inlet and 40mm venturi for high air flow and increased HP throughout the RPM range
• Dual throttle cable linkage
• Accelerator pump
• Improved fuel delivery system
• Redesigned slow speed transfer port system
• Features a slow jet, main jet and 'new' intermediate jet
• Intermediate fuel port
• Enrichenor circuit for cold starts
• High flow (low restriction) reusable paper air filter element by K&N, designed by Harley Davidson
  Reduces turbulence and offers excellent filtration
• Chrome air cleaner cover with logo
• Requires a support bracket adapter kit for installation

Harley-Davidson motorcycles equipped with some Screamin’ Eagle® high-performance engine parts may not be used on public roads.
And in some cases must be restricted to closed course competition.
This engine related performance part is intended for racing applications and is not legal for sale or use in California on pollution controlled motor vehicles.
Engine related performance parts are intended for the experienced rider only.

On 1988 and later models, you must replace the intake manifold.
Use a stock replacement 1987-style manifold for proper installation of the carburetor and air cleaner kit.
Kit Includes:

• Carburetor assembly
• 2 Gaskets
• 1 Manifold spacer
• 2 Allen head bolt, 5/16“-18 x 2”
• 2 (ea) Washers and lockwashers, all 5/16“
• 1 Air cleaner adapter assembly
• 2 Allen head bolts, 1/4”20 x 2-3/4“
• 2 Nuts, 1/4”-20
• 4 Washers, 1/4“-20
• 1 Carburetor gasket
• 1 Back plate
• 4 Button head screws, 1/4”-20 x 3/4“
• 2 Support spacers, 5/16” ID
• 2 Support spacers, 17/32“ ID
• 2 Hex head bolts, 5/16-18” x 3-1/2“
• 2 Allen head bolts, 1/2”-13 x 3-1/2“
• 2 Washers, 5/16” ID
• 2 Washers, 17/32“ ID
• 2 Lockwashers, 5/16” ID
• 2 Lockwashers, 17/32“ ID
• 2 Air cleaner cover spacers
• 2 Counter-sunk allen head screws, 5/16”-18 x 5/8“
• 1 Crankcase breather hose fitting
• 1 O-ring
• 1 Hose clamp
• 1 Venturi
• 1 Air cleaner element
• 1 Vacuum hose kit

• 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 ⁶⁾

⁷⁾

*in carburetor

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• 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“. ¹²⁾
• 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.