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Tillotson High Volume (Double Stack, Alky) Mylar Fuel Pump Diaphragm
Tillotson Alky (Methanol) Mylar Fuel Pump Diaphragm
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Tillotson High Volume (Double Stack, Alky) Mylar Fuel Pump Diaphragm

Part Number: 237-255MYL
Online Price: $2.99
Phone Order Price:$3.99
You Save:$1.00(25%)
Tillotson High Volume Alky Fuel Pump Diaphragm (Double Stack) – 237-255MYL
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Description

Tillotson High Volume (Double Stack, Alky) Mylar® Fuel Pump Diaphragm – 237-255MYL


The Tillotson High Volume Mylar Fuel Pump Diaphragm (237-255MYL)—also known as the Double Stack or Alky Stack—is a key performance component designed to increase fuel delivery in high-demand racing engines. This diaphragm is engineered for use in Tillotson diaphragm carburetors that require enhanced fuel flow for methanol (alky) or high-output gas applications.


Unlike standard diaphragms, the High Volume design separates the fuel pump diaphragm from the fuel inlet/check valve diaphragm, allowing the use of an extra plate in double-stack pump configurations. This results in greater fuel volume delivery, making it an essential upgrade for methanol conversions and high-RPM race engines.


Product Features & Benefits

  • High Volume / Alky-Ready Design
    Double-stack construction separates the pump and inlet diaphragms for greater fuel delivery
  • Durable Mylar® Construction
    Made from clear Polyethylene Terephthalate (PET/Mylar), known for stability and fuel resistance
  • Methanol Conversion Essential
    Ideal for converting gas carburetors to methanol (alky) use in racing applications
  • Race-Proven Compatibility
    Used in many of EC’s built carburetors for high-performance, alcohol-fueled engines


Applications & Compatibility

Fits a wide range of Tillotson high-volume diaphragm carburetors, including:

  • HL-304WX, HL-314F & G, HL-334WXA, HL-339A, HL-341A, HL-342A
  • HL-348 Series (A, B, C, D, E), HL-355 Series (A, B, C, D, E)
  • HL-360B, HL-360C, HL-380A, HL-380B
  • HR-181B, HR-184A, HR-190A, HR-191C, HR-191G, HR-196A
  • And other high-volume double stack (alky) Tillotson carburetors

Note: This diaphragm is not compatible with standard single-stack fuel systems. Always verify your carburetor model before ordering.


Recommended for Best Results

  • For methanol conversions, pair with an EC Pro Gasket Kit or Pro Rebuild Kit
  • Replace old or worn diaphragms during routine carburetor servicing or rebuilds
  • Required for high-volume pump plate conversions on Tillotson carbs

FAQ

What’s the difference between this and a standard fuel pump diaphragm?

This is a high-volume (double stack) diaphragm that separates the fuel pump and inlet check valve, allowing for greater fuel delivery—especially important in alky (methanol) setups.


Is this diaphragm only for methanol-fueled engines?

While designed for methanol (alky) conversions, it can also be used in high-performance gasoline engines where increased fuel flow is needed.


Can I install this in a single-stack carburetor?

No, this diaphragm is made for double-stack fuel pump assemblies. Attempting to install it in a single-stack setup may cause improper sealing or fuel delivery issues.

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