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EC P7-RK Pro Rebuild Kit for HR High Volume(Double Stack, Alky)Carburetors
P7-RK EC Pro Double Stack HR Rebuild Kit
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EC P7-RK Pro Rebuild Kit for HR High Volume(Double Stack, Alky)Carburetors

Part Number: P7-RK
Online Price: $26.99
EC P7-RK Pro Rebuild Kit for HR High Volume (Double Stack) Carburetors – Ultimate Racing Performance
Availability: In Stock.

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Description

EC P7-RK Pro Rebuild Kit for HR High Volume (Double Stack) Carburetors


Complete High-Performance Rebuild Kit for HR-Series Carburetors — Gas & Methanol Ready

The EC P7-RK Pro Rebuild Kit is engineered for HR-series high volume (double stack) Tillotson-style carburetors used in high-performance small engine racing and vintage applications. Whether you're building for karting, 2-cycle racing, 4-cycle gas engines, or even vintage snowmachines, this kit delivers unmatched precision, durability, and completeness.


Race-Grade Components for Elite Engine Builders

Developed for professional engine builders and DIY racers alike, our EC Pro Gasket Kits are designed using OE or upgraded aftermarket parts that prioritize performance and reliability over cost-cutting. Unlike other kits that skip key components, ours includes everything you need for a complete and correct rebuild, down to the fuel strainer cork gasket and tension spring.


Key Performance Features

Fast Action Main Diaphragm (Wagon Wheel Style)

Designed in-house by EC, this aftermarket metering diaphragm improves throttle response and fuel delivery precision. The “wagon wheel” center ensures consistent dowel height, smoother fulcrum arm movement, and superior surface finish compared to both OE and generic alternatives.


.093" Alky Inlet Seat (Short with Cross-Hole)

Included is our short alky seat with a .093" orifice (0.538" length), perfect for methanol or high-flow fuel delivery. This inlet seat is widely used across:

  • Methanol-fueled racing carburetors
  • Rotary or reed valve 2-cycle engines
  • Large displacement 2-cycle and 4-cycle gas engines

While referred to as an “alky” seat, this component is not limited to methanol applications.


Captured Fulcrum Arm and Needle Assembly

The captured-style fulcrum arm “locks” onto the dowel of the inlet needle, maintaining firm contact for consistent metering. This setup is ideal for carburetors mounted with the fuel pump stack facing downward, such as in oval kart racing or vintage sleds.


Exclusive Parts Diagram Included

All EC Pro Kits include a detailed exploded parts diagram that identifies every component and aids in proper reassembly—a feature not offered by OE or most aftermarket kits.


Kit Contents:

  • Fast Action Main Diaphragm
  • Metering Diaphragm Gasket
  • Fuel Pump Diaphragm
  • Fuel Pump Diaphragm Gasket
  • Inlet Valve Diaphragm
  • Inlet Valve Gasket
  • Brass Fuel Strainer Screen
  • Fuel Strainer Cork Gasket
  • .375" Welch Plug
  • .093" Inlet Seat with Cross Hole (0.538" Length)
  • Captured Viton Inlet Needle
  • Captured Fulcrum Arm
  • Inlet Seat Copper Gasket
  • High/Low Side Needle O-Rings
  • 1.375" HR Flange Gasket
  • Red Cap (91A-351R)
  • Inlet Tension Spring (021)


Compatible Carburetors

The P7-RK Pro Kit fits all HR-series high volume (double stack) carburetors that do not require an accelerator pump, including:

Modern HR Racing Carburetors:

  • HR-181B
  • HR-191G

Vintage HR Snowmachine Carburetors:

  • HR-17C, HR-75A, HR-76A, HR-131A, HR-133A
  • HR-164A, HR-165A, HR-166A, HR-168A, HR-172A
  • HR-173A, HR-174A, HR-178A, HR-180A, HR-184A

This kit is also suitable for 3-plate HR carburetors and other double-stack HR models that don’t use an accelerator pump.

Not sure if this is the correct kit for your application? Contact us with your carburetor model number—we’re happy to help.


Looking for the HL version?

If you're working with an HL-series double stack methanol carburetor, check out our P8-MRK Pro Kit instead.

FAQ

1. What carburetors does the EC P7-RK Pro Rebuild Kit fit?

The EC P7-RK Pro Rebuild Kit is compatible with HR High Volume (Double Stack) carburetors, including models such as HR-181B and HR-191G, as well as vintage HR snowmobile carburetors like HR-17C, HR-75A, HR-76A, and more. It’s perfect for carburetors that don’t require an accelerator pump.


2. Does this rebuild kit work for methanol engines?

Yes, the EC P7-RK is designed to support methanol-based applications, especially with the short alky seat (.093") and the BOPET Mylar® diaphragm, making it ideal for 2-cycle reed engines and 4-cycle methanol racing engines.


3. What’s the difference between the EC P7-RK and EC P8-MRK kits?

The P7-RK is tailored for HR-series carburetors while the P8-MRK is designed for HL-series carburetors. Both kits include high-performance components, but the P8-MRK is ideal for methanol double stack HL carburetors, while the P7-RK is best for HR double stack carburetors.


4. Can I use this kit for vintage snowmobile carburetors?

Yes! The P7-RK rebuild kit is compatible with many vintage HR snowmobile carburetors, such as HR-17C, HR-75A, HR-131A, and others. If you're restoring or rebuilding a vintage engine, this kit has the necessary components to bring your carb back to life.


5. What makes the EC Pro Gasket Kit different from others?

Our EC Pro Gasket Kits include exclusive features that other aftermarket kits don’t, such as:

  • Detailed parts diagram for easier reassembly.
  • Fast Action Main Diaphragm for superior throttle response.
  • Captured fulcrum needle assembly for greater consistency.
  • BOPET Mylar® diaphragm for better fuel and chemical resistance.


6. Do I need special tools for this rebuild?

While basic tools such as screwdrivers and wrenches will be necessary, we recommend using precision tools when checking your fulcrum arm height and making sure all parts are correctly seated. For the best results, always follow the provided parts diagram and reassembly instructions.


7. Can I use this rebuild kit for gas carburetors?

The P7-RK kit is optimized for HR-series high volume (double stack) carburetors, which can be used for both gas and methanol applications. If you're rebuilding for gas-powered engines, simply ensure your carburetor doesn't require an accelerator pump.


8. How do I know if this rebuild kit is right for my carburetor?

If you're unsure, check the model of your carburetor or contact us with your carburetor's part number. The P7-RK kit is designed for HR double stack carburetors and fits a wide range of racing and vintage models. We’re happy to help you confirm compatibility.


9. Does the rebuild kit include all the necessary gaskets?

Yes, the EC P7-RK kit includes all the essential gaskets, including flange gaskets, inlet seat gaskets, and needle o-rings. All gaskets are made from high-quality materials designed to withstand the rigors of racing and high-performance use.

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