Injectors

This page provides detailed information about the fuel injectors used in the Honda RC51, including their specifications, connector details, visual references, and technical documentation as well as their integration into the FT Manager.

Fuel Injector Description and Ohm Readings

The Honda RC51 (RVT1000R) uses four fuel injectors, two per cylinder (primary and secondary). These are Denso high-impedance, top-feed injectors. Each injector is a solenoid-operated valve controlled by the ECU, with the primary injector handling base fuel delivery and the secondary injector supplementing at higher RPMs or under heavier loads. The injectors are labeled as Injector 1-1 (rear primary), Injector 1-2 (rear secondary), Injector 2-1 (front primary), and Injector 2-2 (front secondary), following the sub-harness labeling convention where the rear cylinder is designated as Cylinder #1.

The resistance (ohm readings) of the injectors is critical for verifying their functionality. Using a multimeter across the injector terminals, the expected readings are:

If readings fall outside this range, the injector may be faulty and should be inspected for clogs or electrical issues. Always disconnect the injector connector before testing to avoid ECU damage.

Being high-impedance injectors, an external injector driver is not required, and the FT ECU can handle the injectors directly.

Connector Data

The fuel injectors on the Honda RC51 use 2-pin connectors integrated into the fuel injector sub-harness (FISH). See the table below for specific injector and connector type information:

Note: Polarity is not critical for the injectors, as they are simple solenoids, but always verify pin assignments with the RC51 service manual to ensure proper connection to the sub-harness. See the FI Sub-Harness page for a wiring diagram. The 22 AWG gauge for the injectors is sufficient for splices from the main +12V line.

Sourcing the Injector Connector

You can source the connector for the four injectors from the following locations (ensure they are High Key):

• Motorcycle Terminal - 6195-0041
• KSV Looms - SKU: OE10269
• Corsa Technic
• ProWireUSA

Additional specifications can be found here.

Flow Testing the Injectors

I sent my injectors in for cleaning and flow testing. While they were not excessively dirty, the process provided valuable data about the OEM injectors. I used Fuel Injector Clinic. They replaced all seals, filter baskets, and cushioning rings as part of the service—an excellent value considering the cost of purchasing those components separately.

Below are the results of the flow test before and after cleaning, along with the Data Match report:

• Flow Testing Results
• Data Match Results

OEM Denso injectors are rated at 310cc/min (but test around 305cc/min) and have an average dead time of 1ms.

Fuel Injector Setup Guide

Step-by-Step Instructions

1. Open FT Manager.
2. Navigate to Engine Settings.
3. Click on the Fuel Injection tab.
4. Locate the (Primary & Secondary) Total Flow input field.
5. Convert your injector flow rate from cc/min to lb/hr using the formula below, then enter the result for both Primary and Secondary.
6. Set the Injector Dead Time according to your injector specifications.

Conversion Formula: cc/min → lb/hr

Fuel injectors are often rated in cubic centimeters per minute (cc/min), but many ECU systems require the value in pounds per hour (lb/hr).

Formula:
lb/hr = cc/min ÷ 10.5

• cc/min = injector flow rate in cubic centimeters per minute
• 10.5 = conversion factor (cc/min to lb/hr)

Example Calculation

            lb/hr = 305 ÷ 10.5
            lb/hr ≈ 29.05 lb/hr per injector
        

Setting Injector Dead Time

Injector dead time (also called latency) is the time it takes for the injector to open and close, typically given in milliseconds (ms).

Enter the value provided by your injector manufacturer, often specified for different battery voltages. Example:

            Voltage (V) | Dead Time (ms)
            ----------------------------
            13.5        | 1.00
        

I only received a single entry for this parameter, 996ms @ 13.5V. We will see if I run into any issues down the road, especially at startup or high RPM.

Fuel Injector Reference Images

Explore our curated collection of high-resolution images showcasing the OEM fuel injectors for the Honda RC51. These visuals highlight the injector body, electrical connectors (pin and seal sides), and fully assembled injector units with connectors, providing a clear and professional reference.

Wiring Diagram

Refer to the FISH documentation for wiring of the fuel injectors.