S-25A Single Throat Mechanical Fuel Injector 2-1/16″ or 2-3/16″


This basic injector unit is designed for a single cylinder engine. For each additional cylinder, another Extra Single Throat is added allowing for change in engine configurations at a minimum cost.
Contact us to place an order or get a quote.

Product Description

This basic injector unit is designed for a single cylinder engine. For each additional cylinder, another Extra Single Throat is added allowing for change in engine configurations at a minimum cost.

Standard Features:

  • Fully assembled with shaft, butterfly, linkage, metering valve, nozzle, by-pass valves included
  • Extra Single Throat assembled without a metering valve
  • Ram tube, pump, drives, sold separately


  • Can be used in turbocharged application
  • Casting machined for V-band flange at additional cost

Contact us to place an order or get a quote.

Additional Information

Bore Size

2-1/16″, 2-3/16″


Single Throat

Sales Policies

Payment Policy: While we make every effort to fill and ship individual parts orders in a timely manner, complete injector kits and special orders may require more time due to the fact that each injector unit is built and flow tested to meet our customer’s individual engine specification and racing application. We accept all major credit cards or COD payments by certified funds. All shipments to foreign countries must be pre-paid.

Shipping Policy: 
Air shipments are available, however, unless otherwise specified, we will ship your order via United Parcel Service-ground. Orders sent to foreign countries can be shipped via United Parcel Service to most areas or by another specified Air Freight Forwarder (freight collect).

All retail prices referenced in the following pages are subject to change without notice. The current retail selling price at the time of shipment will apply to all orders. We cannot guarantee that all items referenced in the products catalog will continue to be available.

Return Authorization/Claims: 
Merchandise may be returned only within 30 days from the invoice date and only with pre-authorization. Refund, credit, repair, or exchange are given at our option after factory inspection. Returned items will be subject to a restocking fee of 10% of the list price. Returns must be sent freight pre-paid by the original purchaser and each item accompanied by the invoice number and purchase date. Merchandise returned COD, or after 30 days from the invoice date, will not be accepted. Claims for shortages must be made immediately upon receipt of your order.

Merchandise sent in for service and flow testing does not require a pre-authorization. Please include your name, address, and contact number along with any relevant specifications such as cubic inch of engine, type of fuel, type of racing, size of fuel pump etc…

: Our fuel injectors are manufactured strictly for use with high performance engines for racing and off-highway use only, and are therefore subject to the unusual stresses normally associated with this type of use. Since the operation of these engines is far in excess of the safe limits that are usually set for engines, breakage and failures are common, and are an accepted risk in racing. Also, the history of racing has always been one of trial and error by the users of this type of equipment. Therefore, because of the many unknown factors involved in experimentation, and because of the safe limits being exceeded by virtually every part in the engine, we do not offer a warranty of any kind on our equipment. It is purchased and used by the buyer at his own risk and with this understanding. If any of our parts become defective after purchase, the buyer assumes all cost of service or repair.

: Fuel Injection Engineering (FIE) is providing all information herein to familiarize potential customers with its’ products and services. Because racing is inherently dangerous, no representation of your safety is implied. To the extent permitted by law, this warranty is exclusive and in lieu of all other warranties or representations, whether expressed or implied, including any implied warranty of merchantability or fitness for a particular purpose. In no event will FIE be liable for special or consequential damages.

Finish Options

All HILBORN manifolds come standard with a clear anodize coating which provides the timeless nostalgia grey finish.

But customizing your HILBORN Injection to make it everything you’ve dreamed of is easy with our custom finish options. See below for a description of these options. Be sure to visit our finish options page to view colors and examples.

Polishing/Ceramic Clear Coating
Few finishes beat the glow of a highly polished manifold, making this is our number one finish option. Polishing can be mixed and matched with other finishes to provide a one of a kind manifold not soon forgotten.

Love the polished look, but not the constant upkeep required? Pair your polished manifold with our clear ceramic coating that eliminates the ongoing maintenance. Our clear ceramic is a high temperature, non- yellowing, scratch and impact resistant coating that eliminates the constant upkeep needed with bare aluminum. Once the manifold is polished, it receives a high temperature steam bath to remove any polishing residue before the ceramic finish is applied. Our ceramic clear will keep your manifold looking like new for years to come.

Ceramic Coating
Our ceramic coating is a high temperature, scratch and impact resistant coating, typically used on headers, that will protect your manifold from the bumps and bruises experienced by any application that is driven, raced or worked on frequently. Available in select colors and as a matte finish only, they are perfect for those looking for the best overall protection or to fit the more high tech looking engine bay that is trending today.

Powder Coating
For the most comprehensive color and texture options, powder coating is the best choice. With literally hundreds of colors available we’re sure you will find the perfect color for your special ride. Check out our powder coat color chart to see the numbers offerings!

Chromed ram tubes are the crowning touch to your HILBORN fuel injector and is the perfect maintenance free option that fits with any manifold finish.

Unfortunately we are unable to chrome the manifold itself.